The lack of standardization in the fermentation process of cocoa beans (Theobroma cacao L.) directly affects the quality, price sold and acceptance in the chocolate industry. Therefore, adjustments to the standard fermentation process are necessary to improve the quality and acceptance of the almonds. The objective of this study was to analyze the influence of increasing levels of fermentation trough aeration on the chemometrics of cocoa beans. Cocoa fruits harvested in the municipality of Altamira-Pará were used. The troughs were adapted with different percentages of aeration in relation to the standard, being: T1 – Standard, T2 – Standard + 25% a holes in the troughs and T3 – Standard + 50% of holes. the parameters evaluated were: fermentation temperature in the troughs, biometrics, color, physicochemical parameters and bioactive compounds in the beans subjected to the fermentation and drying process and also a control sample of unfermented and dried cacao beans. The T1 experiment showed an increase increased in the temperature from the second day of fermentation until reaching a maximum value of 44.6ºC on the sixth day. The other treatments (T2 and T3) also showed a similar behavior of temperature increase starting from the second day, reaching maximum temperatures of 46.7º for experiment T2 and 47.1º for T3; however, both experiments reached their maximum temperature on the fourth day of fermentation. The physical-chemical parameters and bioactive compounds of the almonds were altered by the levels of aeration, particularly in experiment T3, where there was a 4% decrease in ash content, a 19% decrease in acidity, and a 41% increase in pH, along with an 18% increase in lipids and a 6% increase in energy value compared to the standard T1. When compared to raw almonds, experiment T3 showed a 29% reduction in titratable acidity, a 45% reduction in carbohydrates, and a 290% increase in pH (which is consistent with the fermentation process, as the microorganisms involved consume carbohydrates and increase acidity due to the organic acids produced by certain bacteria), a 169% increase in lipids, a 29% increase in proteins, and a 28% increase in energy value. Regarding bioactive compounds, experiment T3 showed an 18% increase in total phenolic compounds (TPC), a 9% increase in total flavonoids (TF), and an 8% increase in antioxidants (AA) measured by ABTS compared to the standard experiment T1. In relation to dried raw almonds without fermentation, experiment T3 had a 44% increase in TPC, an 87% increase in TF, and a 178% increase in AA measured by ABTS; this increase may have resulted from the loss of bioactive compounds that could have occurred during the drying process of the raw, unfermented almonds. Regarding the color analysis, the coloration was altered in experiment T3, highlighting increases of 29% in yellow (b), 17% in saturation (c), and 10% in hue (h) compared to the standard T1. In relation to the unfermented raw almonds, experiments T1, T2, and T3 showed higher values for the color parameters. The biometric change was notable only for the width of the almonds in experiment T3, where there was a 10% increase compared to T1. The principal component analysis revealed that lipids, total flavonoids, antioxidants, and the pH of the almonds largely explain (77%) the influence of increased aeration in the fermentation tanks. The aeration process was effective in reducing fermentation time and contributed to the improvement of almond quality compared to the standard method. This technique, by promoting better air circulation during fermentation, favors the development of more complex chemical characteristics, enhancing the uniformity of the process in a shorter time than that used as the standard.

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The aim was to determine crop evapotranspiration and water productivity in fruit trees of economic importance in the Amazon. The study was conducted in commercial plantations distributed in four municipalities in the state of Pará, being located in: Castanhal in açaí plantation (Euterpe oleraceae Mart.), Santa Izabel do Pará in coconut plantation (Cocos nucifera L.), Capitão Poço in acid lime planting (Citrus latifólia T.) and Vitória do Xingu planting of cocoa (Theobroma cacao L.). Towers were installed in all experimental areas, housing meteorological sensors to measure temperature and relative humidity, global solar radiation, rainfall and volumetric water content in the soil. Crop evapotranspiration (ETc) was calculated using the soil water balance method. Water productivity (WP) was determined by the ratio between production and ETc. For the study areas, a completely randomized design with subdivided plots was applied, with two treatments (irrigated and non-irrigated) and two monitoring periods (rainy and less rainy). For ETc data, the Kruskal-Wallis and Wilcoxon-Mann-Whitney tests were applied (p < 0.05). For water productivity data (compared only between treatments), the means were compared by Student's t-test (p < 0.05). For ETc data, during the rainy season (PC), none of the studied fruit trees showed any difference in the treatment averages. In the less rainy season (PMC), the irrigated treatment showed higher ETc averages compared to the non-irrigated treatment. Comparing the periods, in the irrigated treatment, the highest ETc averages for all fruit trees were observed during the PMC in relation to the PC. In the non-irrigated treatment, only the green dwarf coconut and acid lime obtained higher ETc averages in the PMC, while the ETc averages of the açaí and cocoa trees were lower during the PMC compared to the PC. In the Pa results, for the açaí, acid lime and cocoa crops, higher averages of the productivity components were observed in the irrigated treatment compared to the non-irrigated treatment. The observed Pa averages of all evaluated components were higher in the irrigated treatment in the açaí and acid lime crops, while in the cocoa crop, the averages of the evaluated Pa components did not differ between treatments. For the green dwarf coconut experimental site, no comparison was made between treatments due to the difference in plant age. However, when comparing the years 2023 and 2024, an increase in the production of coconut fruits and water was observed in the irrigated treatment, while in the non-irrigated treatment, there was only an increase in the volume of coconut water. In terms of Pa, in 2024, there was an increase in the Pa components evaluated in both treatments compared to 2023. In this sense, it was observed that irrigation enabled better responses to the increase in evaporative demand in periods of lower rainfall. In the water productivity study, irrigation provided satisfactory responses for the productivity components of the fruit trees studied, ensuring greater yield.

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Rice (Oryza sativa L.) is an essential food for more than half of the world's population, and is crucial for food security and the economy. Grown mainly in flooded soils, this crop faces challenges such as low pH and excess iron (Fe), resulting from redox conditions that favor the availability of this element. High concentrations of Fe are toxic to plants, impairing photosynthesis, gas exchange, anatomical structures, the antioxidant system, nutritional status, and biomass production. Therefore, management strategies and the use of biomolecules have been investigated to reduce these effects. Dopamine (DOP) has been studied as a neurotransmitter with a regulatory role in biotic and abiotic stresses. DOP attenuates the toxicity of heavy metals, in addition to mitigating the impacts of salinity, flooding and water stress, through the activation of antioxidant enzymes, improvement of photosynthetic efficiency, modulation of anatomical structures and increase in nutrient absorption and biomass. This study aimed to evaluate whether the exogenous application of DOP reduces oxidative damage in the photosynthetic system of rice plants exposed to excess Fe, in addition to analyzing changes in leaf structure, production of reactive oxygen species (ROS), activity of antioxidant enzymes, nutritional status and biomass. The research was conducted at the Federal Rural University of the Amazon, Paragominas Campus, in a greenhouse under controlled conditions. Ten-day-old rice seedlings were grown in a hydroponic system and subjected to four treatments: two concentrations of Fe (250 μM, control; 5000 μM, excess) and two of DOP (0 μM and 50 μM). DOP was applied to the nutrient solution from the 20th to the 40th day, while Fe was supplied from the 30th to the 40th day. On the 40th day, physiological and morphological parameters were measured, and samples were collected for anatomical, biochemical, and nutritional analyses. Data were submitted to one-way ANOVA and Scott-Knott test (p < 0.05). The results demonstrated that excess Fe causes significant damage to plants. However, DOP promotes nutrient accumulation in roots and leaves, providing Fe content in these structures, in addition to increasing leaf and root anatomy. DOP application minimizes oxidative damage, elevating photosynthetic pigments and increasing PSII quantum efficiency (ΦPSII) and electron transport rate (ETR). In gas exchange, increases in net photosynthesis (PN) and instantaneous carboxylation efficiency (PN/Cᵢ) were observed. DOP also strengthens the antioxidant defense, increasing the activities of superoxide dismutase (33%), catalase (29%), ascorbate peroxidase (75%) and peroxidase (17%), while reducing the levels of reactive oxygen species (O2⁻ and H2O2) and oxidative stress markers (MDA and EL). Although excess Fe reduced biomass, DOP increased shoot, root and total dry matter. Therefore, DOP alleviates the effects of stress caused by excess Fe in rice plants.

Cocoa farming is one of the main agricultural activities in the state of Pará, with the Transamazon region standing out as its primary production hub. Although family farming plays a central role in this context, the leadership of women in cocoa production remains largely underrecognized and undervalued, despite their strong presence across all stages of the value chain. This institutional and statistical invisibility limits women’s access to public policies and hinders the development of more equitable and inclusive strategies. This dissertation aims to analyze the socioeconomic and productive profile of women managing cocoa-producing units in four municipalities of the Transamazon region of Pará, with emphasis on the challenges they face regarding access to land, rural credit, technical assistance, and participation in social organizations. The study is based on primary data collected during a panel survey conducted between July and August 2023, covering 49 women. Although the data were originally collected with a focus on production, they were reinterpreted here through a gender lens. The results show that most women managers have low levels of formal education, self-identify as mixed race (parda), and manage small properties, generally under 100 hectares. Cocoa production is predominantly carried out in conventional systems, with low levels of fermentation or organic certification, although practices such as shading and fertilization are relatively common. Access to rural credit is sporadic, mainly directed at purchasing transport equipment and lacking technical guidance. Technical assistance is discontinuous and rarely tailored to gender-specific needs. Only 41% of the women reported receiving any form of guidance in recent years. Institutional participation is also limited: 67% of the interviewees are not part of any collective organization. It is concluded that, despite some progress, the empowerment of women in the cocoa sector of the Transamazon region still faces structural barriers. There is an urgent need to redesign public policies through a gender-sensitive lens that promotes the recognition of women as producers, expands access to resources, and creates conditions for their full autonomy and permanence in rural territories.

Coconut cultivation is gaining prominence in Amazonian fruit farming, positioning Northern Brazil as one of the largest producing regions on the national scale. The dwarf coconut palm exhibits significant sensitivity to meteorological conditions, which necessitates a thorough understanding of atmospheric effects on this species for its effective management. Given this necessity and the scarcity of information of this nature, the present study aimed to characterize and understand the agrometeorological dynamics associated with the cultivation of irrigated and non-irrigated green dwarf coconut intercropped with the tropical cover crop kudzu under the microclimatic conditions of Santa Izabel do Pará, eastern Brazilian Amazon. The experiment was conducted in a commercial area of green dwarf coconut in Santa Izabel do Pará, Pará, Brazil, considering one irrigated area and another managed under rainfed conditions. A micrometeorological tower was installed in each experimental area to collect meteorological variables, and phytotechnical variables were measured simultaneously. In general, it was observed that climatic seasonality affects critical variables in the cultivation, such as fruit mass, water content, and commercial cycle duration, highlighting irrigation as a stabilizing factor to mitigate seasonal losses caused by reduced water availability. The predominant energy flux in this agroecosystem is latent heat (LE), accounting for 70–80% of the net radiation. The average evapotranspiration in the cultivation was 2.58 (± 0.84) mm day⁻¹, resulting in an adjusted crop coefficient (Kc) of 0.80. The use of satellites for estimating radiation balance components and the three-layer model for evapotranspiration estimation demonstrated good performance indices, indicating that these methodologies can be applied in the region. In this context, the findings provide key insights for crop management, offering essential data for maximizing production and supporting agricultural planning.

The Green Dwarf Coconut (Cocos nucifera L.) is a tropical crop of great economic and nutritional importance, particularly in humid regions. However, its perennial nature makes it vulnerable to climatic variations and extreme weather events, affecting all stages of its development cycle, particularly after inflorescence opening, and consequently, its productivity. In this thesis, we used statistical and machine learning models to estimate the productivity of the Green Dwarf Coconut and assess the impact of meteorological variables and extreme climate events on yield. In the first chapter, we analyzed high-yield (April) and low-yield (November) harvests based on nine years of experimental and meteorological data. We considered variables such as temperature, humidity, precipitation, wind, solar radiation, and radiation balance, as well as derived variables such as vapor pressure deficit, evapotranspiration, and soil water deficit/excess. Multiple linear regression (MLR) models and machine learning algorithms, including multilayer perceptron neural networks (MLP), support vector regression (SVR), and random forest (RF), were tested. Model performance was evaluated using the root mean square error (RMSE), coefficient of determination (R²), and mean absolute error (MAE), along with model interpretation via Shapley Additive Explanation (SHAP). Machine learning models demonstrated superior performance, with MLP being more suitable for high-productivity periods and RF for low-productivity periods. Among the most influential factors, solar radiation and water excess during fruit maturation stood out for high-productivity periods, while relative humidity and vapor pressure deficit were key determinants in low-productivity periods. In the second chapter, we assessed the impact of extreme climate events on the productivity of the Green Dwarf Coconut in northeastern Pará, distinguishing between the rainy period (PC—December to July) and the less rainy period (PMC—August to November) from 2015 to 2023. We analyzed meteorological variables and extreme climate events, including extreme maximum temperature (HT), extreme precipitation (HEP, 90th percentile), and low precipitation (LP, 10th percentile). We developed predictive models using MLR and RF, with RF proving to be the most efficient, achieving an RMSE equivalent to 20% of the average productivity. However, RF exhibited generalization difficulties on the test set, possibly due to overfitting. The inclusion of lagged productivity (P_t-1) demonstrated its significant influence on the models. During the PC, extreme precipitation events and water excess after the fifth month of inflorescence development contributed to increased productivity, whereas in the PMC, low precipitation events reduced yield. In some cases, high precipitation was able to mitigate the negative effects of low water availability. Our results highlight the importance of agrometeorological modeling and machine learning as tools for estimating the productivity of the Green Dwarf Coconut and understanding the impacts of climate variations. Identifying the most influential variables enables the development of adaptive strategies to mitigate productivity losses and enhance crop stability in the face of climate change.

The assessment of areas affected by mining activities is crucial for understanding their chemical and physical attributes, which influence plant growth during the revegetation process, as well as for monitoring potentially toxic elements (PTEs) that may pose environmental and human health risks. This thesis evaluated the use of proximal sensors for the chemical and physical characterization of soils, sediments, and substrates in areas directly or indirectly impacted by mining activities in the Eastern Amazon. Additionally, machine learning algorithms were applied to predict the physical and chemical attributes of these matrices. The predictions were performed using machine learning algorithms, including Random Forest and Support Vector Machine, based on data from proximal sensors. The first chapter explored the use of portable X-ray fluorescence (pXRF) for determining the total and available contents of PTEs in areas affected by artisanal gold mining in the Serra Pelada region. The best regression model fits for total PTE contents were achieved for elements such as Cu, Fe, Mn, and Pb, while the prediction models for available Cu and Zn stood out with high performance. The second chapter, in turn, focuses on the characterization of iron mining pit substrates in the Carajás Mineral Province using pXRF and the Nix Pro™ color sensor, which provide total elemental content and color parameter data, respectively. The results indicated that pXRF and Nix Pro™ can effectively characterize open-pit iron mining substrates by providing valuable information on their elemental composition and color properties. pXRF allowed for the quantification of total elemental contents, particularly Fe, Al, and Si, which are key components of these substrates. Meanwhile, the Nix Pro™ color sensor captured color variations related to mineralogical differences, which are associated with soil properties. Furthermore, data fusion provided slightly improved predictive models for various soil attributes compared to the isolated use of each sensor’s data. Overall, the findings of this thesis highlight the great potential of proximal sensors, specifically pXRF and Nix Pro™, for the characterization of the chemical and physical attributes of areas impacted by mining activities in the Eastern Amazon in a practical, rapid, and sustainable manner.

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Oil palm (Elaeis guineensis Jacq.) is a species of the Arecaceae family, originating in Africa, which has potential for various products and by-products, the main product being palm oil. Due to the large number of areas suitable for palm oil cultivation, Brazil has one of the greatest potential for palm oil production in the world. The quality of seedlings is one of the main factors that affect the oil palm production chain, and this quality will be reflected in production. Therefore, adequate management of the system is a determining factor, among the main practices, there is fertilization, which is one of the biggest costs for agricultural production. Therefore, in order to reduce costs and maintain a high quality standard of seedlings, practices such as silicate fertilization can be a highly impactful alternative, due to its effect on increasing resistance to biotic and abiotic stresses, as well as on development of the leaf and root system, favoring the ability of plants to absorb nutrients, improving efficiency and reducing losses in the soil-plant-atmosphere system, contributing to sustainable agricultural development. The objective of the study was to evaluate the effect of silicate fertilization and a 50% reduction in recommended fertilization on the development of oil palm seedlings based on plant growth, physiological and nutritional analyses. The experiment was conducted for 12 months, on the MEJER company farm, located in the municipality of Santarém Novo - PA. The seedlings used were of the Compacta x Nigeria variety, placed in 50 kilo bags. As a substrate, an organic compost produced by the company and a dystrophic yellow latosol was used, which was corrected and fertilized according to soil analysis, crop needs and treatment composition. The experimental design consisted of randomized blocks with a 2x2 factorial scheme, comprising 4 treatments: two levels of chemical fertilization (100% and 50%) and two levels of silicate fertilizer (30 g and 0 g of calcium and magnesium silicate / bag / changes). To evaluate the effect of treatments, biometric variables, biomass, nutritional and physiological parameters were used. Treatment means were compared using the F test with P ≤ 0.05, the treatment effect size was evaluated using Cohen's d index. In biometric, biomass, physiological and nutritional variables, significant increases were observed for silicate fertilizer in relation to the control. Therefore, it is concluded that silicate fertilizer can be inserted into the oil palm seedling production system to induce early growth with less use of chemical fertilizers, contributing to seedling production with lower production costs and more sustainable.

In the Amazon region, corn (Zea Mays L., Poacea) is considered a cereal of great importance for both human and animal consumption. It is particularly a crop with high demands for macronutrients such as Nitrogen, Phosphorus, and Potassium, essential for plant development. However, given the current high costs of chemical fertilizers in the global market, there is a need for more sustainable and cost-effective alternatives to maintain productivity. In this context, it is believed that reducing the amount of fertilization associated with biofertilization associated with biofertilizers, such as entomopathogenic fungi native to the Amazon, can positively influence the promotion of growth, like the standard 100% of the recommended fertilization for the crop. Thus, the objective was to evaluate the use of entomopathogenic fungi associated with 50% the recommended fertilization to enhance the biometric, physical, biochemical, and anatomical parameters of corn plants. The experiment was conducted in a greenhouse, using a completely randomized experimental design with six treatments and six repetitions. The treatments were: T1- No fertilization and fingi (control), T2- 50% of the recommended fertilization for the crop. T3- Beauberia bassiana+ 50% of the recommended fertilization, T4- Metarhizium anisopliae +50 fertilization, T5- Mix oh Trichoderma asperellum (isolates UFRAT-06, UFRAT-09, UFRAT-12 and UFRAT-52) + 50% fertilization and T6-100% fertilization (recommended standard treatment). All treatments with microrganisms promoted greater growth go corn plants, with 15 being the most efficient for all analyzed variables. Plants inoculated wint T4- M. anisopliae and fertilization, showed higher values in the parameters of net photosynthesis (A), stomatal, conductance (gs) transpiration (E), and carboxylation efficiency (A/Ci), compared to T1(control Treatment). For the intercellular CO2 variable (Ci), the standout treatments were T4 and T5. In the anatomical analyses of the fungi, the best treatments were T4 and T5. Biochemically, all evaluated microrganisms showed satisfaction results for phosphate solubilization, siderophore production, and indole acetic acid (AIA) production. In conclusion, the microrganisms M.anisopliae and T. asperellum associated only 50% of the recommended fertilization for the crop are efficient and the biometric, physiological, biochemical, and anatomical parameters Creole corn plants.

The growth of the açaí consumer market has demanded greater productivity in production systems and, mainly, quality of the product and derivatives, aiming to serve a broader and more demanding consumer market. In this sense, the adoption of traceability systems is of great importance, as it contributes to quality, food safety, sustainability and compliance with current legislation, adding value and strengthening the product's image and consumer confidence. In the state of Pará, the traceability policy of the açaí production chain is implemented by the Agricultural Defense Agency of the state of Pará, through Ordinance No. 2,789/2020, which established the Vegetable Transit Guide (GTV). The objective of the work was to evaluate the process of implementing the state traceability policy in the açaí production chain in the state of Pará and answer the following research questions: (i) how the traceability policy has been implemented in the açaí production chain in the state of Pará, based on the Vegetal Transit Guide (GTV)? (ii) what are the processes, resources, actors involved and results obtained in the implementation of public policy? (iii) what are the perceptions of rural producers regarding this implementation? and (iv) what are the main challenges perceived by producers in relation to this public policy? The dissertation is structured into two results chapters. In the first chapter, Najan's (1995) 5C protocol was used, which establishes five interdependent evaluative dimensions: (i) content, (ii) context, (iii) capacity, (iv) competence and (v) clients and coalitions. The second chapter evaluates the perceptions of açaí producers in the state of Pará about the state traceability policy based on the Vegetable Transit Guide (GTV). The results of this evaluation in this initial phase of implementation offer important information for its improvement over the coming years. There is a positive perception among producers, but there are also a series of obstacles that limit the effectiveness of the policy, which is reflected in the low percentages of producers who consider it to be very good and excellent. For the next few years, greater investments must be dedicated to training, communication and transparency actions, aiming to provide greater support from producers and also social control, allowing monitoring of results with positive effects for the entire society.

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The açaizeiro (Euterpe oleracea Mart) is an Amazonian palm tree with a high profile due to its rich characteristics such as its antioxidant capacity and the production of fruit used as food by the Amazonian population. Organic fertilization improves soil fertility, growth and the mineral nutrition of agricultural crops. There is a great demand for organic products in the state of Pará, especially in agricultural production, so it is necessary to analyze the effects of using these inputs to fertilize the production of fruit. The objective of this research was to evaluate the effect of doses of compost associated with dolomitic limestone on the biometry, nutritional and physiological state of açaizeiro plants in organic farming, contributing to sustainability in the Amazon. The experiment was conducted in the municipality of Santo Antônio do Tauá/PA (1°9′7″ S, 48°7′44″W), in the community of Campo Limpo (1°2′S, 48°10′W). The experimental design used was randomized blocks in a 7x2 factorial scheme, with factor 1 being the six doses of organic compost (2, 4, 6, 8, 10 and 12 kg) and factor 2, the conditions of absence and presence of liming. The control treatment consisted only of chemical fertilization. There was therefore a total of fourteen treatments distributed over six replications, resulting in 84 experimental units, in which each experimental plot had two BRS PAIDÉGUA açaizeiro plants. Dolomitic limestone (PRNT 98.45 %) was used, and the organic compost came from the composting process of the following waste: poultry litter, agro-industrial waste from crops such as andiroba (Carapa guianensis Aubl.), boiler ash, cupuaçu (Theobroma grandiflorum), murumuru (Astrocaryum murumuru) and priprioca (Cyperus articulatus L.). Biometric, nutritional and physiological variables were assessed. The data was subjected to the necessary assumptions, analysis of variance (ANOVA) and test of means. In general, the organic compost provided the best results when the 8 and 10 kg doses were combined with liming, i.e. the organic nutritional management provided important effects on the biometric, nutritional and physiological variables. Therefore, this research showed that the reuse of agro-industrial waste, in the form of organic compost, together with the use of corrective practices (liming) favored the growth, nutrition and physiology of the açaizeiro, contributing to a low-cost and sustainable production alternative for the açaizeiro in the Amazon.

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Jambu is a leafy vegetable with enormous versatility of use, showing potential both for fresh food and for industrial exploitation, due to the biosynthesis of metabolites. However, its productivity varies according to the type of management adopted in the cultivation environment. Thus, the objective of this research was to evaluate the biostimulant potential of Trichoderma spp. in promoting growth, productivity and spilanthol concentration in local varieties of jambu. For this purpose, an experiment was carried out divided into two trials, where in trial I the characterization of biostimulated and non-biostimulated seedlings was performed. In the second trial, the seedlings were transplanted in a greenhouse, adopting a randomized block design, in a 3x4+3 factorial scheme, with four replicates, the first factor being composed of the jambu varieties and the second by the biostimulants, with three additional ones, without inoculation. In the seedling phase, we evaluated plant height, stem diameter and number of leaves. In the field, the days to flowering, physiological parameters, vegetative development, biomass production and spilanthol concentration were evaluated. The Jamb03-MIX treatment was grouped separately, due to the responses for height and diameter of the seedling collar. The physiological parameters were higher in Jamb-16, and the stomatal opening in this variety was influenced by the inoculation. There was precocity of flowering in Jamb-17 plants biostimulated with MIX. The growth characteristics and biomass production of the aerial part were higher in the Jamb16-IBLF006 and Jamb16-MIX treatments, influencing the grouping. The principal component analysis separated Jamb-03 based on inflorescence productivity and internal CO2 concentration. Jamb03-MIX had higher inflorescence production than the other varieties biostimulated with MIX. The spilanthol concentration in the inflorescences of Jamb17-MIX was higher than the additional. On the other hand, the responses of spilanthol in Jamb-03 and Jamb-16 were regulated by intrinsic factors of the variety. Therefore, we found that the inoculation of Trichoderma spp. in jambu can promote the development of more vigorous seedlings, with early flowering in the field, biomass accumulation, and modulation in spilanthol biosynthesis. However, the results are conditioned by the specificity of the interaction.

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Abstract

Boron (B) and zinc (Zn) are essential micronutrient for plant growth. B regulates the structural and membrane integrity of the cell wall and plasma membrane, ion mobility across the membrane, cell division and elongation, reproductive growth, biomolecule synthesis. Zn it plays important roles in plant development, reproduction and signaling due to its structural, catalytic and activating functions. Brassinosteroids (BRs) are a class of steroid hormones that regulate a number of physiological processes. EBR is the most active form of BRs, and exogenous application of EBR can ameliorate the effects of abiotic stresses. Therefore, the objective of this research was to investigate whether application of EBR can alleviate the effects of inadequate boron and zinc supplementation in soybean and tomato seedlings. Two experiments were carried out, the experiment 1 was with soybean plants under three levels of boron supplementation (control, low, and high B) and two EBR conditions (0 and 100 nM), and the experiment 2 was with tomato plants under three levels of zinc (control, low, and high Zn) ) and two EBR conditions (0 and 100 nM). Both experiments was performed at the Campus of Paragominas of the Universidade Federal Rural da Amazônia, Paragominas, Brazil (2°55’ S, 47°34’ W). The study was conducted in a greenhouse with the temperature and humidity controlled. This research has shown that the application of EBR relieved the stress caused by B in soybean plant and Zn in tomato plants, synergistically stimulating leaf and root structures, photosynthesis, and growth. Therefore, our results show that EBR application could help improve plants’ tolerance to boron and zinc stresses.

The thesis focused on urban agriculture, food security and sustainable development objectives, with the general objective of analyzing urban agriculture in the context of food security and sustainable development objectives in three municipalities in the metropolitan region of Belém. The methodology begins with visits to agricultural establishments to present the research project, facilitating the signing of the guarantee of free and informed consent. In the second phase, individual information was collected based on the questionnaire statements on a Likert scale. In the third moment, an interaction relationship was created in the work environment to collect impressions that contributed to the study, using the participant observation technique. In the fourth phase, the data was included in an electronic spreadsheet and in field reports to enable the production of the fifth and final phase, which was the statistical analysis procedure and discussion of the results found. The field visits took place from November 2023 to February 2024. The organization of producers is established through participation in three associations, an agricultural cooperative, three communities, three islands and 15 neighborhoods. Of the 120 producers interviewed, 59 were women and 61 men. The questionnaire criteria were better analyzed when combined with the use of the participant observation technique in an interaction relationship in the workplace. In the statistical stage, the criteria for data analysis and comparison begin with organization in an electronic spreadsheet and subsequently subjected to multivariate factor analysis (AFM). The analysis of variance and the Tukey test were carried out with the help of the SPSS 20 statistical program. The results show contributions of urban agriculture to food and nutritional security and indicate that it is a fundamental strategy for achieving 12 of the 17 sustainable development objectives. However, in the municipalities of Ananindeua, Belém and Marituba, despite urban agriculture offering nutritional, economic and environmental benefits to their populations, who can access different types of environmentally sustainable products, it is a fact that there is a long way to go for managers public, private sector, third sector and citizens to achieve the goals of the UN 2030 Agenda.

The deforestation of the Legal Amazon is one of the greatest environmental challenges faced by Brazil. Over the last few decades, the region has suffered from a high rate of deforestation, which results in loss of biodiversity, soil degradation and contribution to climate change. A temporal analysis of deforestation indicates that, despite ups and downs over the years, deforestation in the Legal Amazon has remained at a worrying level. In recent years, there has been an increase in deforestation, especially in native forest areas. There are several reasons for deforestation in the region, such as the expansion of agriculture, illegal logging and disorderly occupation. In addition, the lack of inspection and effective punishment for those responsible for deforestation also contributes to the problem. To mitigate deforestation in the Legal Amazon and ensure the sustainability of the region, it is necessary to adopt a multidisciplinary approach. This includes the implementation of public policies that encourage forest conservation, the expansion of conservation units and land title regularization. In addition, it is essential to strengthen inspection and punishment of those responsible for illegal deforestation. This can be done by increasing the number of environmental inspectors, creating an efficient monitoring system and applying more severe fines and penalties for those who break the law. Another important solution is to encourage sustainable land use practices in the region. This includes support for agroforestry, family farming and sustainable forest management initiatives, which ensure conscious exploitation of natural resources without the need for deforestation. Finally, it is essential that society as a whole becomes aware of the importance of the Legal Amazon for the environmental balance of the country and the world. This involves environmental education and the establishment of partnerships between governments, civil society and the private sector to guarantee the protection of the forest and the sustainable development of the region. In short, the issue of deforestation in the Legal Amazon requires a joint effort by different actors and the adoption of effective measures to guarantee forest conservation. Only with adequate public policies, efficient inspection and sustainable land use practices will it be possible to mitigate deforestation and guarantee the preservation of the Legal Amazon.

Proximal sensors are a fast, low-cost, environmentally friendly, and reliable method for detecting element content in soil. While previous research has used these sensors in temperate soils, their use in tropical soils, especially in the Amazon region, is still not well-understood. To address this knowledge gap, this study utilized portable proximal X-ray fluorescence spectrometry (pXRF) and visible and near-infrared spectrometry (Vis-NIR) sensors to predict soil texture in 61 municipalities in the state of Pará, Brazil. The study aimed: i) to investigate the performance of pXRF and Vis-NIR data separately and combined in predicting texture, and ii) to compare the effect of surface horizons, subsurface horizons, and combinations of horizons in predicting soil texture. Soil samples were collected from natural areas with primary or secondary forest cover, with at least 20 years of natural regeneration and approximately 20 ha of cover area, in the 0-20 cm and 80-100 cm layers. Soil texture analysis was carried out using the hydrometer method. A portion of the soil samples were analyzed by pXRF and Vis-NIR sensors in triplicates under laboratory conditions. Soil texture prediction was performed using two machine learning algorithms, the Random Forest (RF) and the Support Vector Machine with Radial Basis Function Kernel (SVM). The RF models showed higher R² values and lower RSME and MAE compared to the SVM models. The R² values with data from pXRF, Vis-NIR, and a combination of sensors were, respectively, for sand (0.89; 0.87 and 0.93), clay (0.92; 0.90 and 0.93), and silt (0.91, 0.67 and 0.93). In general, the models for clay obtained higher R² values compared to sand and silt. The prediction using data from the two sensors obtained lower RMSE and MAE values and higher R² values (sand 93%, clay 93%, and silt 92%) in relation to the best sensor individually (Vis-NIR). The prediction model for sand and clay, using Vis-NIR data, obtained lower errors in both horizons and combinations. The effect of combining horizons was minimally important for the models. The results demonstrate the reliability of using proximal sensors to evaluate soil texture in natural soils in the Amazon, which can help reduce costs and save the time required for soil analyses. 

The mineral exploration is essential for global economic development. In the Amazon region, artisanal mining predominates and is carried out on a large scale, with little concern for environmental impacts and human health. This is mainly due to the release of significant amounts of potentially toxic elements (PTEs) (represented here by metals and metalloids) and rare earth elements (REEs). In Chapter 1, the objectives were to quantify the concentrations of Rare Earth Elements (REEs) and estimate environmental and human health risks in artisanal mining areas of cassiterite and monazite in the Amazon region, as well as to understand the dynamics of this risk over time after exploitation. Environmental and human health risks were evaluated in waste materials (sterile and tailings) from three artisanal mining areas of cassiterite and monazite, considering the time of exploitation. In Chapter 2, the objective was to quantify the concentrations of PTEs and estimate environmental contamination and pollution in cassiterite artisanal mining areas in the Amazon region. Environmental and human health risk indices were estimated for PTEs with concentrations above the quality reference value for the state of Pará. The concentrations of REEs and PTEs were quantified through alkaline fusion and ICP-MS. The results were used to calculate pollution indices, environmental risk, and human health risks. The residues from monazite and cassiterite exploitation caused an increase in REE and PTE concentrations, significant enrichment, and a high contamination factor by PTEs and REEs. Waste from active and recently deactivated mines showed high ecological risk. The results indicate that artisanal mining of cassiterite and monazite has the potential for contamination and enrichment by PTEs and REEs. The considerable bioaccumulation in forage plants indicates a high potential risk in a municipality that is the largest producer of cattle in the country. From these results, we can conclude that monitoring and remediation measures should be taken by state environmental authorities.

In recent years, Brazil has significantly expanded the cultivation of green dwarf coconut (Cocos nucifera L.) under irrigation, driven by the increasing demand for coconut water and the establishment of processing industries. Despite the favorable tropical conditions, challenges such as rainfall seasonality and climatic variability in the Amazon justify the adoption of irrigation and fertigation technologies to enhance crop productivity and quality. This study was conducted at Fazenda Reunidas Sococo, in Santa Izabel do Pará, using a randomized block design (3 x 4). The efficiency of different levels of NPK+Mg fertilization (100%, 200%, and 300%) and four soil water tensions (15, 30, 45, and 60 kPa) was evaluated in terms of productivity and coconut water quality. Variables assessed included foliar nutrient concentrations (N, P, K, and Mg), production metrics, and coconut water quality indicators. The results revealed that lower soil water tensions (15 kPa and 30 kPa) combined with higher fertigation levels (200% and 300%) significantly increased productivity, reflected in higher numbers of fruits per plant (NFP), fruit weight (PF), and water volume (VA). Additionally, coconut water quality was optimized, with notable improvements in soluble solids content (Brix) and balanced acidity (ATT) and electrical conductivity. Regarding foliar nutrients, higher concentrations of N and K were observed in treatments with 200% and 300% fertilization, particularly under soil water tensions of 15 kPa and 30 kPa, whereas P and Mg exhibited better performance under moderate tensions (30 kPa and 45 kPa). At higher tensions (45 kPa and 60 kPa), nutrient absorption was reduced, indicating water stress in the plants.

The açaizeiro is a native palm tree in the Amazon with great economic importance for the regional fruit industry, mainly for the state of Pará, the largest national producer, with açaí juice being an iconic product of this state, representing the main product extracted from the palm. Due to the economic potential and expansion of the açaí market, there is a need to produce quality seedlings for the implantation of organic crops in the Amazon, which is strictly related to the use of substrate. The use of organic compounds from residues in the formulation of substrates is a practice adopted by many farmers and presents itself as an alternative from an economic and environmental point of view. The objective of the study was to evaluate the morphophysiological and nutritional quality of açaí seedlings in different proportions of organic waste compost. The experiment was carried out in a nursery at the Universidade Federal Rural da Amazônia, Campus Belém/PA. The organic compost used to compose the substrates came from the organic community Campo Limpo, municipality of Santo Antônio do Tauá, resulting from the composting of chicken manure and residues from açaí (Euterpe oleraceae Mart.), andiroba (Carapa guianensis Aubl. ), passion fruit (Passiflora edulis Sims) and priprioca (Cyperus articulatus L.). The experiment consisted of a randomized block design, with treatments arranged in a 5x2+1 factorial arrangement, with factor 1 (five proportions of organic compost - 0%, 20%, 40%, 60% and 80%) and factor 2 (with and without the use of liming) and the treatment containing 100% of compost. Each treatment had 5 replications and 3 seedlings. At 6, 8 and 10 months after transplanting, biometric evaluations of the seedlings were performed (plant height, stem diameter, number of leaves, leaf area, root length, root volume, shoot dry mass, dry mass root, robustness index and Dickson quality index) and leaf tissue nutritional content (N, P, K, Ca, Mg, S, B, Mn, Fe and Zn), while at 6 and 10 months they were evaluated the physiological parameters (chlorophyll index, net CO2 assimilation, stomatal conductance to water vapor and transpiration rate). The results reveal that the use of these organic residues in the formulation of substrates promoted an increase in biometric, physiological and nutritional parameters, resulting in quality seedlings suitable for definitive planting. In this way, these substrates produced from these residues constitute a promising alternative in relation to commercial substrates, resulting in quality seedlings, in addition to contributing to the reduction of the purchase of fertilizers, minimizing the costs with commercial substrates, reducing the environmental impacts caused by the disposal of these materials, in addition to providing a noble and rational end to these residues.

Knowledge of the characteristics of materials produced in manganese (Mn) mining in
southeastern Amazonia may be essential for defining contamination levels and for
correct environmental management in altered areas. In this sense, the objectives of this
study were to characterize the properties and determine the pseudototal and bioavailable
concentrations of potentially toxic elements (PTEs) in soils, overburden and by-product
of Mn mining at the Azul mine, southeastern Amazonia. For this purpose, samples were
collected from overburden piles and Mn mining by-products, as well as soils from
native forests, considered as reference. The samples were characterized in terms of
chemical properties and granulometry. Mn, barium (Ba), copper (Cu), molybdenum
(Mo), nickel (Ni), lead (Pb) and zinc (Zn) concentrations were determined by acid
digestion and inductively coupled plasma mass spectrometry. Bioavailability was
obtained using the sequential extraction proposed by the Community Bureau of
Reference. The results were used to estimate contamination rates and ecological risks.
The pH values of the forest soil and the by-product were more acidic than in the
overburden, and the organic matter contents were higher in the reference forest area. All
EPTs showed higher concentrations in waste and by-product, especially Mn, Ba and Cu.
In these same materials, Mn, Ba, Cu, Zn and Pb had greater enrichment and
contamination. The ecological risk index was high in overburden (309.55) and by-
product (592.67). The chemical fractionation revealed that all EPTs predominate in the
residual form, with percentage concentrations above 60% of the pseudototal
concentration, revealing the strong association of the elements with the crystalline
structures of the minerals and the low risk of environmental contamination. The results
of this study may support more efficient monitoring and the development of new
technologies for mineral processing and environmental recovery in Mn exploration
areas.

A desnutrição humana ou fome oculta acomete pessoas em vários países. Diante disso, diversas estratégias têm sido utilizadas para mitigar o problema, sendo uma delas a biofortificação agronômica, que consiste na introdução de nutrientes essenciais aos seres humanos por meio da suplementação desses nutrientes às plantas. Existem evidências de escassez de selênio (Se) nos solos amazônicos, bem como, trabalhos que evidenciam a insuficiência do consumo de zinco (Zn) por mulheres grávidas e crianças. O jambu, sendo uma hortaliça muito consumida no Norte brasileiro, apresenta potencial para biofortificação com Se e Zn. Assim, neste trabalho teve-se como objetivo avaliar os efeito da suplementação com Se e Zn no crescimento, fisiologia, desenvolvimento e acúmulo de  Se e Zn em variedades de jambu (flor roxa e amarela). Foram realizados dois ensaios experimentais conduzidos em casa de vegetação, no delineamento de blocos casualizados, com cinco repetições. O primeiro consistiu de um experimento no arranjo fatorial (5 x 2), sendo cinco doses de Se (0; 1,0; 2,0; 3,0 e 4,0 mg L^-1) e duas variedades de jambu (flor roxa e amarela). O segundo consistiu de um arranjo fatorial  (6 x 2), sendo seis doses de Zn (0; 1,0; 2,0; 3,0; 4,0 e 5,0 mg L^-1) e duas variedades de jambu (flor roxa e amarela). No primeiro experimento foi avaliado crescimento, a produção, a pós colheita, teor de clorofila, as trocas gasosas e os teores de Se, já no segundo o crescimento, a produção, a pós colheita, as trocas gasosas e os teores de macro e micronutrientes. Os resultados obtidos foram submetidos à análise de variância, quando significativos, realizada a análise de regressão. Verificou-se que o Se interferiu no crescimento e nas respostas produtivas do jambu, observando-se, em geral, que as maiores respostas foram obtidas com a dose de 1mg L^-1 para variedade roxa e 2mg L^-1 para variedade amarela, bem como foi verificado acúmulo para essas doses, concluindo assim, que as variedades foram biofortificadas. Além disso, o Zn interferiu no crescimento e nas respostas produtivas das variedades de jambu, observando-se, em geral, que o melhor desempenho de ambas as variedades foram obtidas na dose de  2mg L^-1, e que, foi verificado acúmulo de Zn nas partes comestíveis, concluindo assim, que as variedades foram biofortificadas.

The oil palm (Elaeis guineenses Jacq.) among the oilseed crops, is the most productive in the world, standing out in the production of oil of high economic value. The production of seedlings requires a long period in the nursery and the water supply is essential at this stage as it is the main limiting factor in the quality of seedlings. However, there are studies that show that microbial technology (fungi and bacteria) is effective in promoting growth and mitigating the negative effects of water deficit. The study was composed of two chapters, being chapter 1 with the following hypothesis that microorganisms alter photosynthetic performance to promote the growth of oil palm seedlings. The objective of this chapter was to evaluate the biometry, biomass accumulation, gas exchange and chlorophyll a fluorescence in leaves of oil palm seedlings inoculated with microorganisms. The experiment was carried out in a greenhouse in a completely randomized design with five treatments, comprising the inoculation of four microorganisms (UFRABA01, UFRABA124, FT12, MIX of fungi) and control (without inoculation) with five replications per treatment. The inoculation of microorganisms promoted the growth of oil palm seedlings. The height, stem diameter, number of leaves, leaf area, root length and total chlorophyll increased by an average of 37%, 49%, 16%, 223%, 63% and 15%, respectively, in the inoculated seedlings in relation to the control seedlings. The dry mass of leaves, shoots, roots and totals increased by an average of 214%, 228%, 213%, 71%, respectively, in the inoculated seedlings compared to the control seedlings. Net photosynthesis, stomatal conductance and transpiration increase by an average of 62%, 25% and 22%, respectively, in inoculated seedlings in relation to control seedlings. For chapter 2 thesis as a hypothesis that the inoculation of microorganisms as a mitigator of damage to the photosynthetic apparatus caused by water deficit. The objective is to evaluate the biometry, gas exchange, water potential, lipid peroxidation and activation of antioxidant enzymes in oil palm seedlings inoculated with microorganisms and submitted to water deficit. The experiment was carried out in a greenhouse with a completely randomized design. The treatments consisted of inoculation of microorganisms (UFRAB01 and MIX of fungi) and a control (not inoculated), with five replications, in oil palm seedlings submitted to full irrigation and submitted to water deficit (-2.5 Mpa). The inoculation of UFRAB01 and MIX increased the height and diameter of the collar regardless of the water condition. The water potential decreased in all seedlings submitted to water deficit, with the greatest reduction of 75% in the control seedlings. Net photosynthesis was drastically reduced by the water deficit, but the inoculation of UFRAB01 and MIX managed to alleviate this reduction and maintained the highest averages, about 63% higher than the control. Stomatal conductance and transpiration were reduced by water deficit, however the inoculation of UFRAB01 and MIX managed to regulate these processes to increase water use efficiency by 23% and increase carboxylation by 51% compared to the control. Lipid peroxidation (MDA) was not affected by inoculation of microorganisms. Probably, some physiological mechanisms involving the regulation of stomatal opening and greater rubisco carboxylation activity may be being activated by microorganisms to sustain the greater demand of photoassimilates necessary for greater growth and to alleviate the alterations by other non-enzymatic defense systems.

Difficulties in access in areas of the Amazonian biome have limited economic and agro -environmental planning analysis in the northern region of Brazil. In this sense, the soil digital mapping tools (MDS), notably, machine learning techniques have helped to obtain quality soil maps and known accuracy. And considering the variability of models available today, it is important to evaluate their performance in relation to the data set and environmental variables involved in the digital soil mapping. This work aimed to perform the digital mapping of soils of the municipality of Tracuateua/PA, on a scale 1: 100,000, evaluate different methods, and determine the set of significant environmental covariables that represent the soil formation factors and explain the local pedological variance. The study evaluated the performance of two machine learning algorithms (Radon Forest - RF and Recursive Partitioning - RPART) for soil mapping in the municipality of Tracuateua/PA, Northeast Paraense, Eastern Amazon. 44 geomorphometric covariables were used from a digital elevation model - MDE, obtained from Palsar, local geology and Landsat 8 satellite vegetation rates, using GIS 2.3.2 saga software and qgis 3.16.11. In the SFWARE R 4.2.0, covariable selection was selected by the collinearity elimination algorithm and successively. 2 machine learning algorithms were tested as classifiers, and the analyzes were conducted using the Dplyr, Tidyr, Forcats, Tibble, here, Caret, Earth, Grepel, GGPLot2, SF, Readr, Janitor, Future and Future packages. Preliminary results indicate that the two algorithms performed similar performance (Kappa 0.44-0.66). Soil classes: (Yellow Latosol - LA, Yellow Argisol - PA, quartzenic neosols - RQ) and Hydromorphic Plains (Hamable Gleissols - GX) obtained greater agreement with the conventional map, with greater performance of the algorithms. In general the global agreement rate obtained by the map algebra showed that the result was satisfactory, with 49-60 % agreement between the conventional soil map and maps produced by machine learning. The most disagreement areas in MDS occurred in the PA unit due to low correlation with environmental variables. The performance of the models was satisfactory, with good agreement with the conventional soil map, this highlights the importance of MDS as a potential complementary tool to assist soil mapping in difficult areas in Brazil, especially in regions, as in the Amazon

The present study aimed to evaluate the agroeconomic viability of 'Tahiti' acid lime (C. latifolia (Yu. Tanaka) Tanaka) in commercial planting, aiming to present production results, productivity, costs and post-harvest losses, contributing to the management strategy for exporting citrus fruits from Northeast Pará. To answer the problem question, the research highlights as specific objectives: Analyze the situation of the lemon market in the state of Pará, specifically in the regions where the citrus poles are located, from the international, national and regional context of culture; To evaluate the economic viability of the acid lime tree 'Tahiti' from the production, productivity and production costs in commercial cultivation for the domestic market and for export of the fruit. To evaluate the percentage of post-harvest losses of 'Tahiti' acid lime in the packing house as a possible implication in agroeconomic viability, identifying its causes. Given the above, it is noteworthy that each specific objective generated a chapter for the master's dissertation. - 2nd chapter: Situation of production and market of limes and lemons in Brazil and in the State of Pará. - 3rd chapter: Economic dynamics of 'Tahiti' acid lime in commercial planting for domestic and export markets from northeastern Pará. - 4th chapter: Post-harvest losses of 'Tahiti' acid lime in commercial plantation for export.

The Amazon has high potential for the development of beekeeping and meliponiculture due to territorial extension, climate and flora diversity. These activities combine the fundamental requirements of sustainable development, as they provide important environmental services, in addition to adapting to the social and productive context of regional family agriculture. The Northeast of Pará is one of the most important regions of honey production of bees in the Amazon, however, there is a lack of studies that address socioeconomic aspects and, mainly, that address strategic elements for the sustainable development of this production chain. The objective of this dissertation is to evaluate is to estimate the economic value of bee environmental services, identify the determining factors of honey production and the sustainable development strategies of the honey production chain in northeastern Pará. The data collection will be based on the official databases of several institutions related to the promotion, production and commercialization, as well as primary research with agents of this production chain. The expectation is that the results can subsidize strategic plans and public policies for the sustainable development of the honey production chain in northeastern Pará.

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Brazil is the seventh largest cocoa producer in the world and the 17th world exporter of the commodity. Although it represents a small share of this market at an international level, Brazilian cocoa farming has high socioeconomic importance in the domestic market, in addition to great development potential, due to the growth of its production chain and the sustainable expansion of cocoa. The Brazilian cocoa market has undergone transformations, since our country was once the world's largest producer of the crop and currently, due to a serious structural crisis that began with witches' broom contamination, it needs to import cocoa beans to supply the national industry. Seeking to better understand this scenario, this work aimed to verify the dynamics of how price and production have influenced Brazilian cocoa exports in recent decades. The data used in the work were obtained from the Institute of Applied Economic Research (IPEA), ComexStat and the Brazilian Institute of Geography and Statistics (IBGE), for the period from 1994 to 2020. Tests of stationarity and cointegration of the series were performed. and the Vector Error Correction (VECM) model was used to determine the short-term and long-term relationships. Regarding the results, it was observed that the variables Cocoa Export (EXP), Cocoa Quantity Produced (QPC) and Average Cocoa Price (PMC) are cointegrated. The adjustment coefficient revealed that cocoa market imbalances are adjusted at a rate of 56.2% per year. In the short term, it was noted that the lagged price and production positively influence contemporary cocoa exports. It is recommended, for future research purposes, the inclusion of more explanatory variables in the model, complementing the study and contributing to the formulation of public policies.

The açaí palm (Euterpe oleracea Mart.), native to South America, is considered a palm tree of great economic importance in the Amazon region. The high sensitivity to water deficit limits the production of seedlings and hinders the expansion of commercial plantations. Biostimulants can be used as an efficient strategy to reduce seedling losses, as they increase tolerance to the negative effects of water deficit (DH) and help plants recover after rehydration. The objective of the study was to evaluate the effect of the biostimulants Bacillus subtilis (BS) and Fertiactyl GZ® (BC) on changes in gas exchange, oxidative stress and accumulation of osmoregulators caused by water deficit and to analyze the capacity of biostimulated seedlings in water recovery after a period of water deficit. The experiment took place in the greenhouse of the soil building of the Universidade Federal Rural da Amazônia-UFRA, in Belém, Pará. The study was divided into two chapters, the first one referring to the imposition of water deficit with 4 treatments and 6 repetitions. The treatments consisted of non-inoculated plants (control) and inoculated with BS, BC and BS + BC, which were evaluated under full irrigation conditions and after 7 and 14 days of water suspension. At 7 days of water deficit, the seedlings biostimulated with BC increased, respectively, 76%, 100%, 39% and 75% to A, gs, E and A/Ci. At 14 days of water deficit, plants with BC and BS+BC increased by 71% and 35% to A; 100% and 63% on gas; 75% and 25% to A/Ci and with BC, 64% to E, in relation to the control. At 14 days of water suspension, Ψw was 24% and 35% higher in seedlings biostimulated with BS and BC, compared to non-biostimulated ones. The proline content was higher in biostimulated seedlings, being more expressive in plants with BS, 75% higher than the control. At 14 days of DH, the MDA content of the control plants was statistically higher than all averages of the biostimulated plants. The highest enzymatic activity of SOD and CAT was found for BC and BS+BC and of the APX enzyme for the BS+BC treatment. The objective of the second chapter was to evaluate the photosynthetic and physiological performance of açaí seedlings after rehydration and was composed of 5 treatments and 6 replications. The treatments were BS, BC, BS + BC and non-biostimulated plants (DH control and IRR control), which were evaluated in water recovery condition at 0, 7 and 14 days of rehydration. At 7 days of rehydration, compared to the DH control, all biostimulated plants had statistically higher means of A and A/Ci. Plants with BC increased 101% A and 100% A/Ci. When compared to the IRR control, all treatments showed statistically lower means of A, gs, E and A/Ci. At 14 days of rehydration, plants inoculated with BC and BS+BC presented, respectively, 20.2% and 25.3% higher A; 29.4% and 35.3% higher A/Ci compared to control in HD. Compared to the IRR control, biostimulated plants showed statistically the same average of A and A/Ci. Açaí seedlings biostimulated with BS, BC and BS+BC accumulated more proline than control plants DH and IRR, at 0 and 14 days of rehydration. At 14 days of water deficit, the levels of MDA in control plants increased by 20.3% in relation to plants with BC. The BS+BC treatment showed higher activity for the SOD, CAT and APX enzymes in 49.6%, 160% and 75.5% higher than the DH control, respectively. The application of BC and BS+BC can be an efficient alternative to reduce the losses of açaí seedlings in non-irrigated nurseries or located in regions with defined periods of water restriction and can contribute to increase the availability of seedlings for the field that are more tolerant to the deficit. water.

Abstract

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Gold (Au) is exploited by rudimentary methods in several artisanal mines in the Amazon, which generates residues that can harm the ecosystem and public health with pollution by rare earth elements (REEs). The objectives of this study were to determine the concentrations and risks of REEs in areas altered by artisanal Au mining in the southeastern and northeastern Amazon. The areas studied in the southeastern region referred to the zone of influence of the Serra Pelada artisanal mine, located in the municipality of Curionópolis, state of Pará, and included agricultural, urban, mining, and native forest areas. In the northeastern Amazon, the studied areas corresponded to artisanal Au mines in Cachoeira do Piriá, state of Pará, where miners use methods such as underground exploration, reprocessing by cyanidation, and surface colluvial mining. The collected samples were submitted to chemical and granulometric characterization. The concentrations of REEs were quantified by inductively coupled plasma mass spectrometry and used to estimate levels of pollution and risks to the environment and human health. In general, the properties showed marked differences between areas without significant anthropic impact and altered areas, which had lower levels of organic matter and less acidity. Most REEs had higher concentrations in anthropized areas when compared to reference areas. The most alarming contamination factors were observed for lanthanum (La) and yttrium (Y) in agricultural areas in Serra Pelada, and for cerium (Ce), europium (Eu), La, neodymium (Nd), praseodymium (Pr), samarium (Sm), and scandium (Sc) in the underground and cyanidation mining areas in Cachoeira do Piriá. The highest enrichment factors were observed for Y in Serra Pelada, ranging from 18.2 to 44.4, and for Ce, La, Nd, Pr, and Sc in Cachoeira do Piriá, ranging from 5.5 to 20. Ecological risks from individual exposure to REEs were low in all studied areas, but simultaneous exposure was associated with risks ranging from moderate (167.3) to high (365.7) in Cachoeira do Piriá. On the other hand, risks to the health of adults and children were not evidenced. The results of this study indicate that mitigation measures must be implemented to protect the environment from the impacts of REEs, considering the levels of pollution, enrichment, and ecological risks of these emerging pollutants in areas altered by human activities in the eastern Amazon.

The natural conditions of low fertility and high acidity of the Amazon soils poses challenges for the sustainable agricultural production in the region. The use of alternative soil techniques which may avoid burning the forest down are generally dependent on the application of fertilizers and lime, non-renewable and expensive resources. The objective of this study was to evaluate the performance of an agroforestry system model implemented in newly deforested areas without the use of external inputs. For that, we evaluated the growth of twelve species, including native and fruit trees, in three gap areas with similar climate and soil characteristics, located in the National Forest of Caxiuanã, State of Pará. In general, after three years of follow-up, there was a reduction in soil fertility and difficulty in establishing the most nutrient demanding crops. Species such as Colubrina glandulosa, Carapa guianensis and Vouacapoua americana showed a low mortality rate and regular growth, while fruit trees species such as Musa paradisiaca, Theobroma spp. and Psidium spp. faced difficulties in establishing themselves in the system, showing symptoms of mineral deficiency and growth rates below expectations. The results suggest that the implementation of AFSs under these conditions should be carried out in two steps, using key species in order to improve the soil fertility before the introduction of the more demanding crops. The selection of species, the arrangement used and the adoption of specific practices for managing organic matter are important decisions to ensure a sustainable agroforestry production in the region.

Differences in species composition between local communities (β diversity) depend on several factors biotic and abiotic as environmental conditions and biological interactions. Knowledge of elements such as the richness and abundance of beetles, characterized by response to changes in the environment, are decisive for the maintenance of forest environments and their biodiversity. With this, the objective is to understand the spatial dynamics and dissimilarity of the weevil beetle community arboreal in two habitats with different plant structures in Eastern Amazonia. The study was carried out in the municipality of Paragominas (PA), two forest fragments were selected in a bauxite mining area: a remnant of natural forest and an area undergoing natural recovery after 5 years of closure of bauxite mining activities. At each site seven 250 × 4 m (1 000 m²) transects were selected, where all trees and shrubs with a circumference at breast height of > 10 cm and leaf area height up to 10 m were sampled. The collections were carried out bimonthly from January 2019 to January 2020, where the collection of beetles was used the arboreal arthropod collector, to assess species composition across habitats, Hill number diversity profiling, diversity partitioning, and β diversity. In total, 465 specimens were captured, with a predominance of the subfamilies Curculioninae (45%) and Baridenae (21%), the five most abundant morphospecies were Anthonomus sp1 (136 ind. 30%), Mandarini sp1 (72 ind. 16%), Anthonomus sp2 (26 ind. 6%), Cryptorhynchini sp1 (25 ind. 6%) and Udeus_sp1 (14 ind. 3%). The forest area showed no difference in total beta diversity when compared to the natural regeneration area. Species turnover was the main contributor to β-diversity (92.2%), while nesting contributed 7.8%. We found a positive relationship between total β diversity and the geographical distance when beetle communities from both habitats were combined (Mantel test: r = 0.2771 P = 0.012).  Our results illustrate the significance of turnover in the regeneration area and demonstrate that the composition pattern of beetles is a function of environmental factors, and that it is necessary to monitor and evaluate the ecological processes in the area, in order to guarantee the success of natural regeneration.

The Law 11. 947/09, which establishes the National School Feeding Program (PNAE), brought important advances, particularly with regard to the stimulation of family production with the establishment of the requirement of at least 30% for food purchases from family agriculture with resources from the Program. The state of Pará has a significant participation of family agriculture in the state's production, representing 38.6% of the value of agricultural production and 85% of establishments, according to the IBGE Agricultural Census of 2017. The PNAE is an important public policy instrument aimed at ensuring healthy and adequate school feeding. The objective of this study was to analyze family farming and the PNAE in the state of Pará, from 2010 to 2020, based on a systematic review of the literature, the analysis of the instruments of management and control of government public policies and the performance of the application of the resources of the Program in the state. Research was carried out in secondary sources, literature review with qualitative approach with the use of descriptive method and quantitative with the use of indicators. The information used for the research was obtained from the audit reports of the Public Draws Program of the Comptroller General of the Union (CGU), the portal of the National Fund for the Development of Education, the National Institute of Educational Studies and Research Anísio Teixeira (Inep) and the Brazilian Institute of Geography and Statistics (IBGE). The results of the analysis of the CGU reports showed problems in the execution of the Program, in the state, related to irregularities in acquisitions, purchases of family agriculture below 30%, precarious conditions in the preparation and irregular supply of snacks and, poor performance of the School Feeding Councils (CAE). The performance analysis showed that there was a reduction in the number of schools and students from public schools served by the program, as well as a reduction in the amounts transferred in the period. A positive result was the increase in the acquisitions of family agriculture with PNAE resources, leading to the achievement of the percentage of 30%, by all mesoregions of Pará in 2019. In general terms, the results of the analysis of the systematic review are very similar to those found for the state of Pará, studies in other regions have also shown advances in increasing the purchases of family farming, in the supply of healthier foods for school feeding, however, they show results that signal that there is still much to be done to achieve a satisfactory performance of the Program,  as little interaction of local managers with family farmers, poorly organized family farmers, lack of structure for the performance of the School Feeding Councils and lack of equipment for storage of food in natura. All these obstacles prevent greater purchase of products from family agriculture and, therefore, make it difficult to meet the minimum acquisition of 30% with resources from the Program.

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The permanence and succession of artisanal fishing and small family farming properties represent a challenge to the survival of rural and social development. Fewer and fewer young people are showing interest in remaining in the countryside, and their desire to continue the agricultural activities carried out by their parents is even lower. Understanding the scenario in which the process of family succession of these activities finds itself, seeking alternatives that can minimize the rural exodus and contribute to the permanence of young people in the countryside, become necessary and urgent, since these issues threaten the generation of income and jobs and local food production. For the study, municipalities belonging to the Northeast Pará mesoregion were chosen, due to their rural characteristics based on family farming and artisanal fishing. The thesis is composed of four chapters. Chapter II consisted of a systematic review of the literature, carried out in accordance with the PRISMA guideline, which led to the identification, screening and inclusion of works suitable for analysis, which resulted in 87 articles relevant to the topic. For the construction of the other three chapters, different models of questionnaires were developed aimed at managers of agricultural establishments and their children, totaling a sample of 280 participants belonging to the municipalities of Bragança, Viseu and Augusto Corrêa, in Pará, in order to understand the perceptions of possible successors and identify the expectations of heads of rural establishments regarding generational succession in their production units. The articles that made up chapters III and IV made use of quantitative and qualitative data, developed from descriptive analyses, enriched with bibliographic and documentary research procedures. Chapter V used the Q Methodology guidelines, developed in four main stages: Concourse and sample selection on the specific subject (Q-Set or Q-Sample); sampling of participants (P-Set); application of the methodology (Q Sort) and (4) factor analysis and descriptive statistics. After analysis, it was found in article I that the studies focus mainly on the opinion of the main farmer and young farmers, and disregard other family members, especially women. It was observed that the South region covers 67.4% of publications, with emphasis on Rio Grande do Sul, while the state of Pará represents 3.37%. The articles highlight that the valorization of agriculture, diversified production, pluriactivity, young people's participation in decision-making and family support would stimulate generational succession on agricultural properties, while financial difficulties and access to credit, the unplanned succession process, lack of public policies, gender inequalities and scarcity of rural technical assistance are the main factors that negatively influence the succession process. Regarding chapters III and IV, it was observed that the desire of young people to abandon the countryside is mainly influenced by the utopian desire for financial autonomy (21.7%), combined with the hardship of agricultural activities (16.7%), the lack of investment in productive units (15.4%) and the low economic return (12.2%) from artisanal fishing and agriculture and they receive, in most cases, there is support from their parents for abandonment, the who say they do not want their children to continue with the activities, as they consider them exhausting (55.8%). The scenario shows that the main conditions for young people to stay in rural establishments is their pride in their parents' profession (41.7%), followed by the appreciation of the activity (26.7%) and the expectation of income (21.7%), but potential successors also attribute that the incentive (55%) and greater openness of managers to decision-making in activities (56.7%) could positively influence their permanence. In turn, family leaders believe that factors such as liking to live in rural areas (34.2%) and owning their own business (28.3%) can favor the social reproduction of these families. Finally, it was found that 88.3% of family managers had not yet heard of this term, nor had they received any guidance (99.2%). In their perceptions, their children no longer want to remain in the activities (50.9%) and perhaps, because of this, they have not yet been able to define a successor (52.5%), opting to increasingly encourage their children to migrate and seek better living conditions in more developed cities. Chapter V highlighted seven main points of view regarding succession from the girls' perspective, namely: working conditions, living conditions, attractiveness of socialization, family support, associative organizations, institutional support and attractiveness of rural and financial autonomy. Therefore, it is concluded that there is a lack of encouragement from parents and preparation for the succession process, a lack of interest on the part of young people, as well as the need for public policies through the actions of responsible bodies, which offer conditions to stimulate these girls and boys, through alternatives that promote prospects of prosperity and then socioeconomic advancement, favoring their permanence in the countryside and then the maintenance and development of these activities.

Parauapebas, despite the marked urban growth in recent decades, faces gaps related to urban planning and public policies directed to the fundamental needs of the population. Mining is the main economic matrix of the municipality. However, socioeconomic and environmental aspects point to the need to diversify the local economy. In this context, urban agriculture can contribute to food production, income generation, and the use of urban idle spaces. This approach is seen as an alternative to mitigate the impacts of disorderly urban growth, with the potential to promote substantial improvements in the quality of life of the population. This thesis is organized into five chapters, the first of which presents a contextualization of the research theme. The second chapter focuses on the analysis of urban land use and occupation in Parauapebas, identifying and quantifying urban voids, as well as evaluating the potential of these spaces for urban agricultural practices. The third chapter addresses the survey of the socioeconomic profile of vegetable producers in one of the neighborhoods of Parauapebas, with the objective of analyzing the productive dynamics of horticulture developed in the Nova Carajás neighborhood. The fourth chapter analyzes the relationship between urban agriculture and the urban master plan of Parauapebas, identifying challenges and opportunities for the integration of these practices in urban planning. In the last chapter, the conclusions and propositions are presented. The results of this study contribute to the formulation of public policies aimed at reducing socioeconomic and environmental challenges, promoting sustainability and the social well-being of its population.

The lettuce (Lactuca sativa) is the most commercialized leafy vegetable worldwide, having its consumption predominantly in the form "in natura", being the crespa type the most commercialized in Brazil. However, this crop comes from temperate climates, presenting some limitations in production and development, mainly due to the precocious bolting, which is recurrent in regions that present temperatures above 28 °C. In this sense, the objective of this work was to evaluate the performance of crisp lettuce cultivars in a hydroponic system in a hot climate region, as well as the effects of Mg concentrations in the nutritive solution. To accomplish this, two experimental trials were conducted in an entirely randomized design. The first trial evaluated the biochemical, productive, physiological and postharvest quality performance of 9 cultivars of crisp lettuce, as well as their suitability for cultivation in warm climatic regions. The second trial evaluated the effect of concentrations of 0.01, 0.5, 1, 2 and 4 mmol Mg L^-1 on antioxidant enzyme activity, electrolyte leakage from leaves, physiological performance, growth, yield and postharvest quality of two lettuce cultivars with different suitability for warm climatic regions. Based on the results of the first trial, it was possible to observe a greater productive aptitude of the cultivars Olinda and Cristina, which did not express bolting, and also presented a better productive performance in relation to the other materials evaluated. We highlight the differences between the two cultivars, which serve two distinct markets in alfaculture. We also observed that among the materials tested, the variety Monica is the most susceptible to fruit set in regions with hot climates, due to its greater precocity and degree of expression of bolting. As for the effects of Mg concentrations, we observed that the contemplation of Mg nutritional status was not sufficient to mitigate the expression of early bolting. However, Mg promoted improvements in antioxidant responsiveness, photosynthetic performance, growth and yield of lettuce cultivars, with estimated critical concentrations of 2.44 mmol Mg L^-1 and 2.92 mmol Mg L^-1, respectively for Olinda and Monica cultivars.

The Northeast of Pará is the oldest colonization area in the Amazon, characterized by intense human action on nature, with substantial loss of its natural characteristics. The occupation of the municipality of Tracuateua was carried out predominantly by family farmers, who used the slash and burn system as the main practice of preparing areas for crops. This research aimed to evaluate agriculture in the municipality of Tracuateua, through the assessment of the technological level, as well as the socioeconomic aspects and spatial dynamics of land use, aiming to subsidize public policies aimed at strengthening agriculture. At first, through a systematic literature review, to evaluate the scientific production related to agriculture in the northeast of Pará. The second moment of the research included an assessment of land use and occupation associated with official data from the 2017 Agricultural Census, and the elaboration of maps of land use and land cover in three different periods through satellite image processing. And, later, to analyze family farming in the municipality of Tracuateua in relation to the importance of access to the main public policy programs aimed at strengthening agriculture. The results showed that the municipality of Tracuateua presented changes in terms of area occupation by the agricultural sector. In addition, when analyzing the agricultural sector, it was possible to perceive that the technological level and agricultural diversification are low, with little use of chemical inputs and machines and the predominance of the cultivation of only five agricultural crops. Thus, great challenges remain in family farming establishments, so it is necessary to seek alternatives to improve agricultural production, which can become viable through the incorporation of production systems and structural changes in public policies.

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The occurrence of root-knot nematodes in vegetable growing areas causes damage to production. In this scenario, studies for the identification and distribution of root-knot nematodes in the northeast region of Pará, may support control and prevention methodologies. Thus, the objective of this work was to survey and map the occurrence of root-knot nematodes (Meloidogyne spp.) in vegetable-producing areas in northeastern Pará. For this, soil and root collections were carried out in the municipalities belonging to the micro-region of the Caeté river basin, namely: Bragança, Bonito, Capanema, Nova Timboteua, Primavera, Quatipuru, Santa Luzia do Pará, Santarém Novo, São João de Pirabas and Tracuateua. Samples of various vegetables were collected, namely: lettuce, carirú, chicory from the Amazon, coriander, cabbage, spinach, jambu, pumpkin, pepper, chili pepper, cucumber and tomato. The extractions were performed at the Nematology Laboratory (LabNema), at UNESP/FCAV, in Jaboticabal – SP. For the soil samples, the method of centrifugal flotation in sucrose solution was used and for the roots, the method of Coolen and D'Herde, then the populations were estimated and later the species were identified. The identification of the species occurred by the perineal pattern of the female, the labial region of the males and the isoenzymatic phenotype for esterase. In order to represent the population density of eggs and juveniles, chloropletic maps were prepared using the quantile method. To understand the history of the area, questionnaires were applied to the producers. Thus, the following were evaluated: history of the areas, number of galls, absolute density of nematodes in the soil and roots, relative density, incidence per location and frequency of nematodes per crop. From the survey, symptoms were noted in “reboleiras”, roots with a high amount of galls, absence of fallow in most production areas, presence of weeds, in addition to other management practices that can impact the dissemination and maintenance of weeds. nematodes. Through the results, the presence of Meloidogyne spp. in all samples collected. The species M. incognita, M. javanica and M. enterolobii were identified. It was also found that M. incognita was the most incident species. It was observed the presence of M. incognita in the cultures of chicory in the Amazon, carirú, coriander, jerimum, cucumber and stingy pepper, it was noted the presence of M. javanica in the cultures of jambu and tomato. In addition, mixed populations of M. incognita and M. javanica were identified for the kale crop and M. incognita and M. enterolobii for the chili pepper crop. Thus, it is possible to identify the occurrence of root-knot nematodes in northeastern Pará, with the species M. incognita, M. javanica and M. enterolobii detected in vegetable production areas in northeastern Pará.

The mining process generates large amounts of solid waste, which have large amounts of potentially toxic elements (PTE’s), which are extremely harmful to the environment and human health (eg arsenic). An example is MAPE (artisanal and small-scale mining) in the municipality of Cachoeira do Piriá, state of Pará, where gold exploration is carried out. In this context, this research relates the use of biochar to reduce bioavailability and
its integration in the assessment of the risk caused by arsenic (As) from gold mining residues, with the purpose of use in environmental remediation programs. In chapter 1, the influence of 3 biochars (açaí kernel, Brazil nut husk and palm kernel cake) on two types of mining residues was evaluated, applied at a rate of 5%. The addition of the 3 biochars provided the accumulation of As in more stable fractions and consequently decreased the bioavailability of As in the two residues. In chapter 2, the influence of enrichment of biocavion with phosphorus (P) using single and triple superphosphate (SFS and SFT) on bioaccessibility, As accumulation in lettuce (Lactuca Sativa) and the interaction of biochar in the evaluation of risk to human health through ingestion of
contaminated soil and plant material. All biochars increased the bioaccessibility of As, due to the increase of P contents in the residue. The addition of biochars provided a decrease in the translocation and accumulation of As in lettuce leaves, with the exception of the excess P condition (SFT). The addition of enriched biochars provided a decrease in risk assessment (HI) levels, mainly related to a decrease in As accumulation in lettuce leaves. The enrichment with SFS obtained the best results mainly in the availability of nutrients, reduction of the accumulation of As in the lettuce leaves and therefore it can be indicated as an environmental remedy, mainly with the help of phytoremediation species.

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The Marandu grass belonging to the genus Urochloa (Syn Brachiaria) is a forage of greatest importance in Brazil and has a larger and larger planted area. Pasture management in relation to mineral fertilization was often neglected by producers. However, this scenario has been changing the application of mineral capo fertilizer aiming at greater agronomic performance is a reality. Technologies that are being primed with which are enhancing nutrient use efficiency, increased plant growth and possibly improved, are the developed and improved changes to the environment. The use of plant growth-promoting microorganisms is used in grass and has the ability to reduce the demand for macronutrients, increase plant growth and act as a bioagent to control phytopathogens, in addition to providing sustainable production. The objective of this work was to select biostimulants capable of promoting greater nutrient use efficiency, improving the photosynthetic apparatus and providing greater plant growth. The experiment was carried out in a greenhouse at the Federal Rural University of the Amazon (UFRA). Initially, three experiments were carried out independently, evaluating the reductions of nitrogen (N) (experiment 1), phosphorus (P) (experiment 2) and potassium (K) (experiment 3), inoculated or not. The experimental design was completely randomized in a 5 x 3 factorial scheme with five replications. The factors evaluated were: mineral fertilizer rate: 0, 25, 50, 75 and 100% of the recommended dose and inoculation with growth-promoting microorganisms: uninoculated, inoculated with Bacillus subtilis (UFRA-92) and co-inoculated with Trichoderma asperellum composed of isolates (UFRA-06, UFRA-09, UFRA-12 and UFRA-52) and Bacillus subtilis (MIX). The inoculation of the isolates was carried out via irrigation and at 35 days after emergence, biometric parameters were measured: plant height, root length, leaf and root dry mass, and the following were calculated: leaf appearance rate, leaf elongation rate, leaf area. The leaves were collected and analyzed for nitrogen, phosphorus and potassium composition. The nutrient use efficiency was calculated from agronomic efficiency, physiological efficiency, recovery efficiency and nutrient response efficiency. From the best treatment and the best doses of nitrogen, phosphorus and potassium found in the first trial, a new experiment was set up in a greenhouse, using these results. The treatments were: plants not inoculated and fertilized with a reduced dose of NPK (C), plants not inoculated and fertilized with a maximum dose of NPK (C+) and plants co-inoculated with Trichoderma asperellum (UFRA-06, UFRA-09, UFRA-12 and UFRA-52) and Bacillus subtilis and fertilized with a reduced dose of NPK (MIX). The experimental design was completely randomized (DIC) with ten replications. Gas exchange based on CO₂ assimilation (A), instantaneous carboxylation efficiency (A/C_i), stomatal conductance (g_s) and transpiration rate (E) were evaluated. Chlorophyll a fluorescence was determined from the potential activity of photosystem II (PSII) reaction centers (F_v/F_o), photochemical extinction coefficients (qP), electron transfer rate (ETR), effective photochemical efficiency of PSII (F_v'/F_m') and non-photochemical extinction coefficients (qN). The total chlorophyll content was also measured with the aid of the SPAD chlorophyll meter and the content of chlorophyll a (Chla), chlorophyll b (Chlb) and total (Chla + Chlb) was quantified, as well as the quantification of soluble carbohydrates: Glucose, Sucrose, Fructose and Starch. Growth parameters were evaluated from plant height, root length, leaf and root dry mass, and leaf area and leaf elongation rate were calculated. The nutrient content of the leaves was quantified: Nitrogen, Phosphorus and Potassium. The results of this study showed that the interaction between co-inoculation and doses was responsible for increasing leaf area, plant height, elongation rate and leaf appearance for nitrogen and potassium, while for phosphorus the interaction was significant for root dry mass. The isolated effect of inoculation on nitrogen doses provided an increase of 104% in root dry mass, 194% in leaf dry mass, 22% in root length and 11% in leaf elongation rate. In phosphorus doses, the isolated effect of inoculation generated an increase of 119% in root dry mass, 156% in leaf dry mass, 51% in height, 20% in root length and 9.3% for leaf elongation rate. At potassium doses, co-inoculation generated an increase of 117% in root dry mass, 34% in root length, 14% in plant height, 50% in leaf area and 20% in leaf elongation rate. Inoculation and co-inoculation showed significant increases in all indices of efficient use of the nutrient. The nutritional content as a function of co-inoculation generated an increase of 256% in nitrogen content, 280% in phosphorus content and 29% in potassium content. The results also showed that co-inoculation provided increments of 25% in CO2 assimilation, 140% and 53% in instantaneous carboxylation efficiency, 34% in stomatal conductance and 30% in transpiration. The variables calculated in the chlorophyll a flowering and the growth parameters had significant increments from the co-inoculation. As well as the chlorophyll content, which had an increase of 353% in chlorophyll a, 349% in chlorophyll b and 352% in the sum of chlorophylls. The content of soluble carbohydrates also had positive responses due to the microorganisms, which showed an increase of 218% in glucose, 36% in sucrose, 775% in fructose and 178% in starch. The nutritional content of co-inoculated plants had an increase of 324% in nitrogen, 387% in phosphorus and 243% in potassium. It is possible to affirm that the application of biopromoters in a co-inoculated form were responsible for increasing the nutrient use efficiency, improving the photosynthetic apparatus, increasing plant growth, providing greater efficiency in the acquisition of water and nutrients and in the transformation of energy into productive gains. In this sense, it is possible to affirm that the microorganisms used can be used as inoculants in Marandu grass, to provide an activity with reduced impacts on the environment.

Several pollutants have been released into the atmosphere through numerous human activities, among these are heavy metals (HMs), which are the main threats to the environment due to their potentially cytotoxic, genotoxic and mutagenic characteristics. Among of HM, Ni and Pb are elements that can cause phytotoxicity, affecting the physiological performance and biomass accumulation. To overcome these negative interferences, brassinosteroids (BRs) emerge as plant growth regulators that perform a variety of physiological functions such as growth, and that also confer resistance to plants against various biotic and abiotic stresses, being 24- epibrassnolide (EBR) one of the most biologically active. In these contexts, the aim of this study was to verify whether the exogenous application of EBR can alleviate the damage provoked by heavy metals induced stress, precisely by Ni and Pb, in tomato plants, evaluating the biochemical, physiological, anatomical, and nutritional responses. Thus, two experiments were planned and executed, the first analyzed the EBR action on deleterious effects of excess Ni (experiment I), and the second evaluated the role of this steroid in mitigating the Pb toxicity (experiment II). The two experiments were randomized with four treatments each, the first with two concentrations of nickel (0 and 400 µM Ni, described as - Ni and + Ni, respectively), and the second also with two concentrations of lead (0 and 200 µM Pb, described as - Pb and + Pb, respectively), two levels of EBR were used in both experiments (0 and 100 nM EBR, described as - EBR and + EBR, respectively). Regarding experiment I, the results showed that EBR alleviated Ni stress through upregulating the antioxidant system, with increments of 44%, 27%, 46% and 35% in SOD, CAT, APX and POX, respectively, assisting to protect photosynthetic machinery and stimulating the accumulation of biomass. While for experiment II, the results demonstrate the interferences caused by Pb stress in tomato plants, however the exogenous application of EBR also mitigated the negatives effects, confirmed by the improvement in root anatomy with increases of 23%, 24% and 20% in RET, RDT and RMD, respectively, consequently promoting gains of 95%, 115% and 92% in leaf, root and total biomass, respectively. Therefore, this research demonstrated that EBR alleviated the damage provoked by Ni and Pb stress in tomato plants.

Mining is one of the most important economic activities for Brazil and the state of Pará, contributing significant amounts to the balance of trade, as well as the resources of financial compensation for mineral exploration (CFEM). Despite this abundance of resources, socio-environmental impacts occur, especially in cities where mineral activity is developed. The municipality of Parauapebas is the largest national producer of iron ore and, consequently, a territory with great socioeconomic impacts ranging from the great migratory flow, thus reflecting the need to increase the availability of products and services related to food, health, education, urbanization among others; even problems related to the awareness of the population about the receipt and correct use of cfem, adding to this the problem of the lack of an alternative economic matrix to ore depletion. The objective of the thesis was to evaluate the impacts of mining on the competitiveness of other economic activities of Parauapebas, especially agriculture and the degree of awareness of the population of the municipality about the impacts of mining, mainly evaluating whether the inhabitants of the city can feel the conversion of economic wealth into human well-being through satisfaction with public services. The results showed that agriculture receives positive and negative impacts from mining, since it receives great financial support from both the government and mining companies through private social investments, but the activity can make little progress in modernization and productivity, due to the negative impacts generated by mining, such as the loss of younger labor and consequently aging of the population of the field,  thus losing the opportunities to explore a consumer market that moves more than one billion reais per year. Another negative impact found both in the urban area and in the rural area was the low territorial belonging, with the population having low interest in establishing residence and participating in the management processes of the municipality as public hearings, sessions of the city council and even in voting to elect the representatives of the public power. Finally, a low rate of social efficiency of public services was found, evidencing the difficulty in transforming mineral income resources into quality of life for the population, and the low capacity of satisfaction for residents even of basic services such as health, education and transportation stands out. The municipality needs a joint effort of public power, private initiative and civil society to become a sustainable territory in the long term so that the life of the city is not restricted only to the useful life of the mines of its territory.

Agribusiness has been one of the pillars for the positive result of the GDP (gross domestic product) in recent years in Brazil. In view of this, the linear growth of this sector has generated greater demand for soil correctives, conditioners and fertilizers, which are inputs that directly affect crop productivity. The use of alternative sources to these inputs has been constantly studied, thus mining and agro-industry can contribute to the alternative development of new inputs for use in soils. In this sense, the state of Pará has the largest aluminum production chain, coming from bauxite mining and, in addition, has a broad agro-industrial development through the cultivation of oil palm, coconut, cocoa, açaí, among others. Occasionally, these chains are potential generators of waste, considered environmental liabilities, which, after chemical characterization, may present potential as soil conditioners and reduce environmental liabilities. The incorporation of oil palm residues that are sources of organic matter and nutrients to bauxite residues (RB), with alkaline properties, high content of organic matter and nutrients, can constitute a product with soil conditioning characteristics, that is, does not compromise the environment and improves soil quality and increases crop productivity. The first chapter of this work aimed to evaluate the physicochemical properties (total N, organic carbon, water holding capacity, cation exchange capacity, carbon-nitrogen ratio, granulometry, macronutrients, micronutrients and PTEs) as well as the ecological risk potential (PERI) of conditioners generated by BR increment under different organic residues of oil palm. For this, we defined a factorial with three doses of BR (25, 50 and 75%) and incorporated in two types of organic wastes from palm oil production (1- fiber, bush and dregs in ideal proportions for composting; 2- mature compost of organic waste from oil palm) in 60 L containers as experimental units and we evaluated after 90 days. The second chapter aimed to evaluate the leaching of chemical elements, estimation of soil and groundwater contamination, soil physicochemical characteristics and agronomic efficiency of Brachiaria grown under soil with application of formulation containing BR and oil palm residues. In this case, we selected the formulations considering the MAPA parameters for soil conditioners, on them we simulated precipitation for 60 days. The columns were composed of PVC pipes filled with 5 kg of medium-textured soil with bottles adapted with hoses to facilitate drainage and collection of leachates. After 60 days, the hoses and bottles were removed and the columns were used as pots for growing Brachiaria. The results indicated that the use of 25% BR associated with oil palm residues constituted a formulation that meets the requirements for soil conditioning. The higher the concentration of organic residues in the formulation the higher the values of cation exchange capacity, water retention capacity, organic carbon, total N, macro and micronutrients, as well as lower sodicity and content of potentially toxic elements (PTEs). The PERI was considered low even with the use of 50% RB. After application of the formulations in the soil the leaching of nine chemical elements was detected, without the presence of EPTs. The treatments neutralized Al3+ in the highest doses of residues and RB and also increased V (55.6%) in relation to native forest soil (10.8%), as occurred with limestone (83%). They also raised soil pH (5.5) in relation to native forest soil (4.7). The production of Brachiaria increased with the use of waste and compared to the native forest soil. Therefore, formulation containing BR and oil palm residues can be classified as soil conditioner without impact on soil and groundwater contamination, besides increasing soil physicochemical parameters and grass production.

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Coconut farming is a major generator of waste, mainly green coconut husk, resulting from the coconut water in agro-industries production. These residues can be converted into biochar (BC), a carbonaceous product, obtained by the biomass of animal or plant origin thermodegradation. When added to urea, BC can constitute a sustainable alternative for the use of these residues and as a potential mitigator of nitrogen (N) losses through the leaching process, when applied to the soil, thus improving edaphic quality. In this context, the aim were: to characterize BCs of residues from the coconut water production produced at 400, 500, 600 and 700 °C, to evaluate the adsorption capacity of ammonium (N-NH₄⁺) and nitrate (N-NO₃^-) in solution of BCs produced at temperatures of 400 and 700 °C; and to evaluate the effect of BC doses added to urea on the leaching of N-NO₃^- and N-NH₄⁺ in two soils with different textures (180 and 880 g kg^-1). Increasing the temperature to 700 °C produced BCs that were more alkaline (pH=10.8) and with a pH_PCZ twice as high compared to that produced at 400 °C. At higher temperatures, BCs showed higher concentrations of K and Ca. BCs produced at lower temperatures have higher yields, volatile material content and fixed carbon. CEC and AEC were increased by 2 and 4 times in BCs produced at 700 °C, which exhibited maximum capacity to adsorb N-NH₄⁺ and N-NO₃^- higher 17 and 70%, respectively, when compared to BCs at 400 °C. The BC produced at a temperature of 700 °C, due to its higher N adsorption capacity and better physicochemical characteristics, was used in the leaching test. Two doses of urea, 200 mg kg^-1 (100%) and 100 mg kg^-1 of soil (50%) were used as experimental control units, to be added to BC. The treatments were as follows: 50% (T1) and 100% (T8) of the urea dose, 50% urea + 10% BC (T2), 50% urea + 20% BC (T3), 50% urea + 30% BC (T4), 100% urea + 10% BC (T5), 100% urea + 20% BC (T6), 100% urea + 30% BC (T7). After the application of the treatments in the soils, the leaching events were carried out after 3, 7, 14, 21 and 28 days, and the leached material was collected for further analysis of the concentration of N-NH₄⁺ and N-NO₃^-. The results enriched with urea (T4 and T6 treatments), reduced by up to 20 and 90%, respectively, the leaching of N-NH4⁺ during the 28 days of evaluation, compared to their respective control treatments in very clayey soil, and 30 and 50% in predominantly sandy textured soil. Reduction for N-NO₃^- leaching, in treatments T4 and T6, was also observed. The product of the addition of biochar from the green coconut husk produced at 700 ºC in the composition of mineral fertilizers, particularly urea, is a material with high potential for mitigating losses inorganic N in soils, regardless of texture.

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Until the beginning of the 1990s, agricultural policies for rural areas in Brazil had a highly concentrated character, to which only large businessmen enjoyed the benefits of a close relationship with the State. The construction of a new trajectory based on support for family-based socio-productive activities occurred in 1995, when the first specific policy for this segment was created, the National Program for Strengthening Family Agriculture (PRONAF), which was designed considering different life spectra. social, environmental and economic development of family farmers to promote so-called sustainable rural development. In view of the fact that public policy evaluations show great potential to assist in the formulation and evaluation of government projects, academic interest in this type of analysis has been growing. However, the studies developed to elucidate the behavior of Pronaf in the North region constitute a real bottleneck in the information available about the Program. Thus, this research aims to characterize the main effects of Pronaf on family farming in Pará. To fulfill this purpose, the initial approach of this dissertation is dedicated to the general analysis of the Program at the national level, taking into account the perspectives of different studies published between the years 2000 and 2020. The second chapter performs the general diagnosis of the supply behavior credit in the state of Pará between the years 2000 to 2019, using methodologies such as shift-share to decompose the sources of credit growth, the Gini Index to measure the level of concentration of resources and the Normalized Rural Credit Index to identify the productive specialties of family farming at the municipal level. Finally, the methodology of the third chapter uses econometric modeling of panel data to verify the existence or not of possible impacts of the Pronaf financing on the agricultural activities typically financed in family farming.

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The consumption of coconut water has been growing significantly in recent years and, consequently, there is a greater demand for the production of the fruit still unripe, which generates an environmental liability, which are the fruit peels. In addition, the bark is difficult to decompose due to the high levels of cellulose and lignin in its composition. In this context, the aim of the present study was to evaluate different formulations of composting coconut husks over time. The experiment was carried out in the composting yard at Fazenda Reunidas Socôco®, municipality of Santa Izabel do Pará, in the Amazon region. The experimental design was randomized blocks in a factorial scheme (5x6) of five treatments (T1: Crushed Coconut Shells (CCT); T2: CCT + 3% poultry litter (CA); T3: CCT + Inoculant (IN); T4: CCT + 3% CA + IN; T5: CCT+5% CA) and six composting times (0, 12, 24, 36, 48 and 60 days) with four repetitions. The contents of nitrogen, phosphorus, potassium, calcium, magnesium, iron, aluminum, sodium, organic carbon (Corg), organic matter (OM), ash and carbon/nitrogen (C/N) of the compost were evaluated. The results were submitted to analysis of variance and Tukey test at the level of 5% probability (p<0.05) using the SISVAR statistical program. Pearson correlation (p<0.05), clustering and Principal Components (ACP) analyzes were also performed using the R Software. There was a significant reduction in C/N, Corg and MO, although the treatments did not differ from each other for variables Corg and MO, and increase in the contents of N, P, Fe, Al and ash in all treatments after 60 days of composting. T2, T4 and T5 reached an adequate C/N ratio (<33) for use as fertilizer faster (36 days), higher values of N, P, Ca and Mg, in addition to lower C/N ratios at 60 days. The C/N showed a strong negative correlation with the N content and moderate with the P, Ca and Al content, in addition to a strong positive correlation with the MO and Corg content. The cluster analysis showed that the chemical characteristics of different formulations change over time, favoring the formation of groups influenced mainly by nutrient content and C/N of the material. ACP showed that the reduction of C/N over time is strongly related to waste mineralization processes. Therefore, the results of this research demonstrate that the composting of coconut fiber, with the addition of CA, is effective in reducing C/N to values suitable for application to the soil in a shorter time, reducing the compost yard time and, consequently, the operating costs involved in the large-scale composting process.

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Soybean (Glycine max (L) Merrill) is a legume of great worldwide interest, being used for human or animal food and part of the biodiesel industry. The complex of insect-pests related to the soybean crop presents itself as an obstacle to the development of the crop. Among the pest insects that most concern soybean producers in the state, is the soybean looper Chrysodeixis includens (LEPIDOPTERA: NOCTUIDAE), which deserves to be highlighted given its difficulty to control and lack of basic knowledge for the implementation of an adequate management. Thus, the main objectives of this work aim to (i) evaluate the population dynamics of C. includens with the help of Geostatistics, and (ii) the resistance of soybean cultivars in the State of Pará. The experimental area is located in the municipality of Paragominas where tests were carried out. of field. The population dynamics of C. includens was evaluated in three consecutive crops (2015/2016 and 2016/2017), correlating the influence of abiotic factors and their spatiotemporal distribution with the use of Geostatistics. For this purpose, weekly samplings were carried out with the use of a batting cloth, and the resistance of soybean cultivars was also evaluated. Field tests were carried out with 20 planted cultivars, among conventional and transgenic (Bt and RR technology). According to the data obtained, it can be concluded that the greatest infestation of the soybean looper occurred during the vegetative period of the culture. Through semivariograms, it was observed that the models that best fit the spatial distribution of the false-measurer caterpillar were: pure nugget, spherical and exponential effect. With range values for an experimental area ranging from 1,80 to 7,30 meters, with formation of aggregation areas for plants with infestation of the false-medium caterpillar. The georeferenced monitoring was an efficient strategy for the characterization of the spatiotemporal variability of the false-measurer caterpillar, constituting an important tool to support the MIP, defining the management in specific characters and consequent reduction in environmental impacts in the soybean crop. The cultivar containing the Bt toxins (M8210 IPRO) was the least preferred by soybean looper; the Round Up tolerant cultivar (P98Y52 RR) showed an intermediate preference between the most and least preferred; cultivars M8867RR and AN sc 89109 RR, showed resistance to small and large soybean looper; the cultivars containing the Bt toxins (IPRO) showed, even so, attack by C. includens; cultivar BRS 9090RR was the most preferred due to the attack of C. includens.

Since its inception, agriculture has been associated with rural areas, giving an urban area an exclusive role as a consumer of agricultural production from the countryside, however, over the years, agriculture has gained notoriety in urban and peri-urban areas. The Metropolitan Region of Belém (RMB) has been experiencing disorderly population growth, with high levels of poverty and unemployment, so agriculture in the metropolitan region of Belém appears as an opportunity for many families, contributing with quality food, acquisition close to the consumer center. It also plays an important role for the population, ensuring the occupation of labor, income, food security, preservation of biodiversity and the best use of spaces. Although it has its economic, social and environmental relevance, it appears that the activity, very often, does not have public policies that correspond to the needs of the population. Thus, the research problem is defined according to the following question: What is the current socioeconomic situation of agricultural activity in the metropolitan region of Belém do Pará – PA? Therefore, this research analyzed the characteristics of agriculture developed in the Metropolitan Region of Belém, with a focus on socioeconomic aspects and rural credit concession. To carry out the research, data from the Brazilian Institute of Geography and Statistics (IBGE) and the Central Bank of Brazil (BACEN) were used and the analyzes were performed using the Microsoft Excel program. Therefore, it was found that the metropolitan region of Belém has as main agricultural economic activity the cultivation of Açaí and Cassava and the municipality with the highest concentration of rural credit was Castanhal. In addition, the need to promote public policies that encourage agriculture in urban areas and facilitate access to credit for a greater number of farmers was observed, contributing, above all, to their development and better quality of life.

Discussions about the importance of the modernization process of Brazilian agriculture in rural development have been gaining strength over the years. Although advances in the process of agricultural modernization in the country are perceived, many regions evolve more slowly, putting pressure on their natural resources, as is the example of the state of Pará. While in the state of Pará, in 2017, 68, 25% of agricultural establishments had access to electricity, a good used strategically in the modernization process, in the country this percentage reaches 83.12%, and in the state of São Paulo, it reaches 88.05% of rural establishments. Thus, given the importance that the changes are linked to the modernization of the territory, more specifically the productive structure of the countryside, this research aims to present a diagnosis of the level of modernization of agriculture in the microregions of Pará, estimating the Agricultural Modernization Index and its determining factors in the period from 1990 to 2019, also evaluating the evolution of the sources of growth and specialization of the main crops in the State of Pará. In the development of the research, data on agricultural production were used, allowing the evaluation of production growth rates, harvested area and yield, in addition to data obtained from the 1995/1996, 2006 and 2017 Agricultural Census of the Brazilian Institute of Geography and Statistics (IBGE), to build an econometric multiple linear regression model analyzing the influence of production factors on the performance of agriculture in the region. The results pointed to a recomposition in the agricultural exploration system of Pará, both of temporary and permanent cultures, where in the first evaluation period, the twenty-two micro-regions were classified with low technological level and in the last analysis, only five continued at this level. Analyzes over time show that production fluctuations in the early 1990s were mainly associated with the expansion of cultivated areas, in contrast to the current scenario, where fluctuations are also greatly influenced by increased productivity. Despite the advances that have already taken place in the modernization of some sectors of agriculture in Pará, it is still evident that there is a considerable discrepancy in the technological level between some microregions. Due to this, increased attention must be paid to public policies, technical assistance and technological innovations. , related to agricultural modernization in the Amazon, with a view to reducing technological distance.

Soybean [Glycine max (L.) Merrill] is a legume of great socioeconomic relevance, both nationally and internationally. Excessive Ni can seriously affect germination, plant growth and impair enzyme activity. EBRs are presented as a new group of phytohormone steroids that act to stimulate a multitude of physiological reactions in the plant including cellular and metabolic functions. Our objective was to reveal the structural, physiological, biochemical, nutritional and growth behavior of soybean subjected to stress by high dose of Ni and to identify the possible benefits caused by EBR. The experiment was randomized with four treatments, including two concentrations of Ni (0 and 200 µM Ni, described as - Ni2 + and + Ni2 +, respectively) and two concentrations of 24-epibrassinolide (0 and 100 nM EBR, described as - EBR and + EBR, respectively. The excess of Ni2 + caused damage to the root and leaf structures, causing anatomical changes in these tissues. At the root, the EBR increased the epidermis (27%), protecting the root from the Ni2 + ion. , significant increases in palisade (11%) and spongy parenchyma (29%). the plants submitted to EBR and Ni dispensed increments in comparison with the treatment without EBR of 50%, 27%, 40% SOD, CAT, APX and POX and 19%, respectively, compared to treatment without EBR Our results confirm that the pretreatment with 100 nM of EBR clearly mitigated the anatomical disturbances caused by the excess of Ni in the structures of the leaves and roots with positive performance also in the attenuation of high nickel dosage in nutritional, physiological, biochemical and growth characteristics in soybean.

Copper is a micronutrient with a role in the development of plants, however, in excess, it becomes phytotoxic resulting in nutritional imbalances and negative responses in biochemical and physiological parameters. Nitric oxide (NO) has been highlighted as a stimulator of the seed germination process and attenuator of abiotic stresses for many species. In this context, the objective of the work was to evaluate the effect of NO as a mitigation agent for copper toxicity in maize (Zea mays L.) in its vegetative, reproductive and grain stages. The first experiment was conducted in the EBPS laboratory (UFRA/Belém campus). The design consisted of DCR-Design completely randomized in factorial 4 x 3, with 12 treatments and 8 repetitions, totaling 96 trays containing 25 seeds per repetition. The seeds of the K9606VIP3 variety were soaked for 48 hours in Germitest paper with a solution containing sodium nitroprusside Na₂ [Fe (CN)₅ NO]2H₂O (0, 75 and 150 µM), as ON donor, sodium ferrocyanide Na₄Fe (CN)₆ (0,75 and 150 µM) as compensator and deionized water (control). Germination was negatively influenced by copper concentrations that promoted an increase in the percentage of abnormal seedlings. There was a reduction in the emergency speed coefficient and a longer average time in the treatment of 200 µM of copper. NO did not attenuate copper toxicity compared to RL. There was no interaction of the effect of NO on LAP and TL, observing the negative effect of copper with increasing concentrations. The dosage of 200 µM of copper provided a lower DMR. ON mitigated the effect of toxicity in relation to MSPA in the dosages of 100 and 200 µM of copper. The dosage of 200 µM of copper promoted an increase in proline in the roots. NO measurements promoted a decrease in this amino acid in BP. The dosage of 0 µM NO promoted a higher percentage of proline in the roots. The second experiment was conducted in a greenhouse. The corn seeds were soaked for 48 hours in Germitest paper with a solution containing sodium nitroprusside Na₂ [Fe (CN)₅ NO]2H₂O (0, 200 and 300µM), sodium ferrocyanide Na₄Fe (CN)₆ (0, 200 and 300 µM) and deionized water. The seeds were sown in buckets with 15kg of soil containing copper concentrations CuSO₄.5H₂O (0, 60 and 200 mg Kg-¹) incubated for 50 days. The design consisted of RBD - Randomized Block Design, with 12 treatments and 4 repetitions, totaling 48 plants. Biometric characteristics (height; leaf area, stem diameter; number of leaves) and chlorophyll content determinations (SPAD index) were evaluated. The chlorophyll a fluorescence and gas exchange were measured. The data were submitted to ANOVA, using the Scoott-Knott test at 5% using SISVAR. There was no effect of treatments on height, leaf area, number of leaves, observing effect only on stem diameter, in which the dosage of 60mg Kg^-1 showed an increase of 32.7% compared to control. There was no effect of treatments on the SPAD index and gas exchange, only on chlorophyll a fluorescence parameters.

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The açaí palm (Euterpe oleracea Mart.) is a plant species native to the Amazon, whose fruits are prominent in the Brazilian and international markets. The growing demand for these fruits encouraged the growth of irrigated plantations on dry land. However, the management of irrigation in these cultivations has not yet been consolidated, since there are no technical and economic assessments considering the different cultivation systems adopted by farmers in the region. The objective of this study was to evaluate the production and economic viability of açaí palm cultivation under different irrigation depths in monoculture and intercropped with cupuaçu trees in the micrometeorological conditions of Castanhal, state of Pará, eastern Brazilian Amazon. The experiment was conducted in area of 0.6 ha (1°19'24.48 "S and 47°57'38.20" W, 41 m), dimensioned in a completely randomized design, where 8 and 10 replications were evaluated for açaí palms and cupuaçu trees, respectively. In the experimental area, a micrometeorological tower was installed to quantify rainfall, air temperature and relative humidity, wind speed, global incident radiation and soil volumetric water content. Irrigation was estimated based on reference evapotranspiration fractions: TS (without irrigation - rainfed), T50, T100 and T150, referring to 50%, 100% and 150%, respectively. During 2018 and 2019, the reproductive phenology of açaí palm, yield, water use efficiency and economic viability indicators of açaí palm and cupuaçu tree were evaluated. The results indicated that water availability significantly affected the yield and water use efficiency in the açaí palm cultivation. The replacement of 150% of the reference evapotranspiration promoted better performance, with yield gains between 43.35% (monoculture) and 44.04% (intercropping) when compared to cultivation without irrigation. The maximum water use efficiency was achieved with the application of T150, corresponding to 3.89 kg ha^-1 mm^-1, in the monoculture area, while the minimum was equal to 0.92 kg ha^-1 mm^-1. Cupuaçu tree had better performance in response to T100, whose fruit production was 68% higher than in TS, following the same trend of water use efficiency, which was maximum in T100 (2.615 kg ha^-1 mm^-1) and minimum in TS (1.105 kg ha^-1 mm^-1). The economic indicators revealed that all treatments are viable in both cultivation systems, but irrigation promoted better performances, especially the replacement of 100% of the reference evapotranspiration in the intercropping, with net present value (NPV) of US$9,952.80, internal rate of return (IRR) of 44.35%, and benefit/cost (B/C) ratio of 1.95. On the other hand, rainfed resulted in lower indicators, especially monoculture, which presented NPV of US$1,696.24, IRR of 21.35% and B/C ratio of 1.19. Therefore, the cultivation of açaí palm intercropped with cupuaçu trees and irrigated with 100% of the reference evapotranspiration generates greater profitability for farmers.

Copper mining (Cu) residues in the Mineral Province of Carajás can be hazardous due to the presence of potentially toxic elements (EPTs) and unfavorable properties that regulate the release of EPTs into the environment. Microorganisms and organic compounds have been used to favor the establishment of plants used for phytoremediation of sites contaminated by EPTs. The aim of this study was to characterize and evaluate the risks of Cu mining residues, and to identify alternatives for the recovery of these materials. The study was carried out in two mining areas of Cu in the city of Canaã dos Carajás-Pará. Plants, soil, overburden and rock waste were collected in the artisanal mine, and in the industrial mine, tailings. Firstly, chemical and granulometric attributes and environmental indicators in soil and mining waste were determined. Posteriorly, the tailings of industrial mining were treated with soil and organic compound of açai kernel in different proportions, and sown with seeds of Cenostigma tocantinum without and with inoculation of bacterial growth-promoting strain, isolated from the roots of Solanum torvum. After 100 days of cultivation in greenhouse, the plants were evaluated for germination, growth and Cu absorption, and the substrates were analyzed for pH, organic matter (MO) and Cu concentration. Descriptive statistics were performed to characterize the residues, and the Scott-Knott test was used to compare the means after the experiment. The pH ranged from 6.2 to 8.0 and the pseudo-total Cu concentrations were high in all residues, reaching 19034 mg kg^-1 in artisanal rock residue. The pollution indexes indicated that the residues are highly contaminated by Cu and moderately contaminated by chrome (Cr) and nickel (Ni). Carcinogenic risk to human health was detected by exposure to Cr in artisanal mining residues. With the addition of treatments, Cu availability was increased by up to 170%. Bacterial inoculation favored the germination of C. tocantinum seeds in untreated tailings. Plants cultivated in the tailings with the organic compound showed higher growth and higher tolerance index. Cu absorption by plants was influenced by bacteria, with root concentrations of 905 and 800 mg kg^-1 in tailings treated with soil and untreated.

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Pests and diseases are the main challenge to agricultural production and the coconut economy in Brazil. The distribution in space and time creates an identity of dispersion of damage caused to plantations. The ‘Lethal Atrophy of the Coconut Crown’ (ALCC) and the Aceria guerreronis mite have become threats to commercial coconut plantations in the country, being able to quickly lead to death of plants and great losses in production. The first objective of this work was to characterize the spatial and temporal distribution pattern of the ALCC in a commercial area of green dwarf coconut plantations in Brazil in the municipality of Santa Izabel, mesoregion of the Northeast of Pará. Monthly evaluations were carried out from January 2014 to December 2018, checking plants with symptoms characteristic of ALCC. The geostatistical technique was applied to perform spatial-temporal estimates of the disease, from the modeling of semivariograms and preparation of ordinary kriging maps. The model that best fit the spatial distribution of the disease was the spherical one, as it presented the best coefficient of determination (R²). The Spatial Dependence Index (SDI) was moderate in the evaluations between 2014 and 2017, except for 2018, which showed strong SDI. The second objective of this work was to evaluate the parameters of spraying in coconut culture. The efficiency and the deposition of drops on the target are important for the effectiveness in combating pests and diseases. The use of an electrostatic sprayer proved to be efficient for coconut spraying. It was observed that the density and droplet size were satisfactory for spraying. Spray coverage and deposition were higher in the middle and lower thirds. As for the parameters, deposition and volumetric distribution uniformity, the best results occurred when volumes of 888 L ha^-1 were used.

The use of biostimulants in banana farming is an alternative to reduce the amount of nonrenewable inputs in Amazonian agroecosystems, as well as improve the economic return of the activity. Thus, the objective was to study the effect of inoculation of microorganisms combined with fertilizer doses on the production of silver banana, and to analyze the economic viability of the technology. A biostimulant (BIO) based on two microorganisms, Trichoderma asperellum (Ufra-06, Ufra-09, Ufra-12 and Ufra-52) and Bacillus subtilis (Ufra-92) were used. The experimental design was completely randomized blocks with four blocks and 4 plots per treatment. Three treatments were used: 100% F (control), with 100% fertilizer dose, without biostimulant; 50% F + BIO, with half the dose of fertilizer plus biostimulant and; 100% F + BIO. The planting was carried out under field conditions in the municipality of Ourém. The experimental period considered the implementation, formation (2018) and first year of production (2019). The first production was evaluated through the characteristics of the bunches and fruits, and the parameters bunches per clump and fruit yield. Economic viability was studied from the analysis of production costs as well as economic indicators (PN, IRR, NPV, B / C, C / B) resulting from a six year cash flow. Biostimulant inoculation plus 50% of fertilization promoted a production performance similar to 100% F. The three nutritional managements are economically viable, however 50% + BIO is more profitable, returning the invested capital faster. Therefore, T. asperellum and B. subtilis biostimulant can be used to reduce the amount of synthetic fertilizers in the production of silver banana, being an economically viable technology, 30% more profitable than conventional nutritional management.

Soybean is a crop of great importance in the world and national scenario, responsible for much of the animal and human food, besides having a great potential for the manufacture of fuel such as biodiesel. However, there are several factors that negatively affect the good production of this oilseed, among these factors are the damage caused by insects, where one of the main is the whitefly. This pest causes direct and indirect damage to soybeans, the latter being characterized by virus transmission that harms many Brazilian crops. Thus, this work aimed to evaluate the whitefly infestation and the spatial distribution of this insect in its developmental stages (egg, nymph and adult), under field conditions, in Paragominas, PA, Brazil. The experiment was evaluated in three consecutive harvests, years 2015, 2016 and 2017, the first being held at the Federal Rural University Campus, making a weekly monitoring of the experiment. And the years 2016 and 2017 in the area belonging to the NAPT (Support and Technology Transfer Center) of Embrapa Eastern Amazon of Paragominas. The experimental design was randomized blocks in split-plot scheme (20 plots x 11 evaluations x 4 blocks), corresponding to the infestation evaluation of 20 soybean cultivars and 11 sampling dates at 07, 14, 21, 28, 35, 42. , 49, 56, 63, 70 and 77 days after emergence. For the descriptive analyzes, the variance (ANOVA) was performed by the F test (Fisher), and the means, when they differed significantly from each other, compared by the Tukey test at 5% probability. And for the geostatistical analysis we used the software SUFFER 7.0. The developmental year 2015 with the highest preference for whitefly was 56 days after emergence. In 2016, at 14 and 21 days after plant emergence, were the most favorable periods for the development of B. tabaci biotype B. In 2017 egg infestations at 7, 14, 21 and 35 DAE were at times of higher incidence of the pest.

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The jambu is a leafy vegetable, widely used in the North region, both in typical dishes and medicinal herb. Its taste is quite peculiar, and the flowers produce a tingling sensation and numbness of the mouth mucous membranes, due to the presence of the spilantol substance. In the last years, the vegetable has been conquering space in the national and international market, however its production is still concentrated in small properties near the capital of Pará. Despite all its importance, the cultivation of jambu, in the North region needs in-depth research on management and fertilization in order to increase its production and quality. In this sense, the objective of this work was to evaluate the effects of liming and nitrogen fertilization on the productive, physiological and post-harvest quality responses of yellow-flowered and purple-flowered jambu varieties. For this purpose, two experiments were carried out under protected environment conditions at the Federal Rural University of the Amazon - UFRA, from February to May 2019. The experiment was conducted in randomized blocks, in factorial scheme (6 x 2), with five repetitions. The treatments consisted of six doses of nitrogen (0; 60; 90; 120; 150; 180 kg ha-1) with and without liming application (0 and 70%V). The characteristics of foliar area, fresh and dry mater, gas exchange, photosynthetic pigments and post-harvest quality were evaluated. Liming improved the efficiency of nitrogen fertilization in the jambu varieties; the dose of 120 kg N /ha-¹ is more suitable for the production of inflorescences in both jambu varieties; the estimated dose of 170 kg N /ha-¹ is more suitable for the production of biomass from the aerial part for yellow and purple flower jambu; the use of a soil improver combined with nitrogen fertilization promoted an increase in gas exchange in the yellow flower variety; on the other hand, only liming influenced gas exchange in the purple flower variety; liming combined with nitrogen doses improved the post-harvest quality of the jambu varieties. The higher dose used (180 kg ha-1) reduced the photosynthetic pigments in the yellow-flowered jambu and the maximum nitrogen doses in the presence of liming increased the contents of photosynthetic pigments in purple-flowered jambu.

The Serra Pelada mine was discovered in the early 1980s, attracting workers from around the world to explore thousands of gold tons until 1990, when the Brazilian government closed the mining activities. Currently, piles of mining wastes are deposited unprotected on the soil surface of the area, which can put the population's health at risk. Some studies have been carried out to characterize environmental contamination by potentially toxic elements (PTEs) in the region, but no approaches have been made on the mobility, bioavailability and bioaccessibility of these elements. Chemical fractionation and oral and pulmonary bioaccessibility of barium (Ba), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were studied in soils and artisanal gold mining residues of Serra Pelada, Pará, Brazil. 10 samples of mining waste, 10 in urban areas, 5 in agricultural areas and 2 in native vegetation areas without anthropic influence were collected. Chemical, physical and mineralogical characterization of the samples was carried out. Pseudototal concentrations were extracted with acid digestion in a microwave oven. Chemical fractionation was obtained by the BCR (Bureau Community of Reference) sequential extraction method, oral bioaccessibility in the gastric and intestinal phases was obtained by the SBET (Simple Bioaccessibility Extraction Test) method, while pulmonary bioaccessibility was obtained through the Gamble solution. The concentrations were quantified by flame atomic absorption spectroscopy and subjected to descriptive statistical analysis. The results indicated contamination by Ba, Cu and Ni, especially for Ba in the mining area. Chemical fractionation revealed that the elements predominated in the residual form, however high concentrations of Ba are in high reactivity forms. The Ba bioaccessible concentrations via oral, in both phases, were higher in areas with a greater anthropic influence degree. Cr and Cu were more bioaccessible in the intestinal phase and Zn in the gastric phase, regardless of the area. Pulmonary bioaccessible concentrations were not found for Ba, Cr and Zn, while Cu, Ni and, mainly, Pb, were bioaccessible via inhalation. The EPTs studied deserve attention for their high total concentrations (which indicate high potential risk), concentrations in the high mobility fractions and bioaccessible concentrations (oral and pulmonary) found in Serra Pelada, mainly in the areas of greatest anthropogenic occupation, where the elements are in direct contact with the local population.

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Amid the various varieties of melon, the net melon has gained prominence in the market competitively because it is a better looking melon with peel and pulp color, aroma, texture, firmness and sweetness. The objective of this work was to evaluate the behavior of the melon in a protected environment, subjected to different soil water stresses and potassium doses applied via fertigation, focused on the climatic conditions of the northeast Pará mesoregion. The experiment was conducted between April and August 2019 at the School of Igarapé-Açu (FEIGA), UFRA, located in the municipality of Igarapé-Açu - PA. The soil of the region consists of a dystrophic yellow argisol of medium sandy texture. The experimental design was a randomized complete block design (DBC), in a 4 x 5 factorial scheme, with 20 treatments and three replications, totaling 60 experimental plots, consisting of five percentage doses of potassium (0, 50, 100, 150 and 200%) of the recommended dose for culture, which corresponded to 0, 123.84, 247.68, 371.52 and 495.36 kg ha^-1 of K₂O respectively and four soil water stresses (15, 30, 45 and 60 kpa) used as an indication of when to irrigate the critical voltage. The variables analyzed were: fruit weight (kg plant^-1), transversal and longitudinal diameter of the fruits (mm), pulp thickness (mm), ° Brix (%) and pH. Significant effect was observed for potassium dose and soil water tension (K x T) interactions, only for pulp thickness (EP), ° Brix and fruit cross diameter, obtaining a better index in the combination of 100% K₂O and soil tension. 37.73 kPa (42.80 mm), 100% (9.5%) and 150% (9.5%) with voltage of 24.67 KPa respectively, showing no difference between both and 43.8 kPa and potassium dose and 100%  (128.88 mm), respectively For fruit weight and longitudinal diameter the best results were obtained when irrigation was performed at 15 kPa tension, with 1.54 kg of plant^-1 fruit and 127.7 mm, respectively. Significant quadratic effect was observed for potassium doses, with larger longitudinal diameter (127, 506 mm) and fruit weight (1.70 kg plant^-1), at 94% and 103%, respectively, of the recommended fertilization potassium. The tension of 15 Kpa presents better results of fruit weight and longitudinal diameter of the fruit under the conditions of the study. Potassium fertilization via irrigation water affects the fruit weight and longitudinal diameter. The interaction potassium doses and soil water stress affect the ° Brix, pulp thickness and longitudinal diameter of the fruits. Soil water stress and potassium dose showed no significant effect on the pH of the melon fruit pulp.

Decomposition is a crucial process for nutrient cycling and carbon storage in ecosystems, but the amount of studies investigating this process in agroforestry systems is still small. The decomposition and release of nitrogen (N) from palm oil residues was evaluated in two agroforestry systems (SAFs) and in a monoculture, both located in northeastern Pará. The residues were classified as empty fruit bunches (CFV), foliole (FOL), rachis (RAQ) and petiole (PEC). During three months of experiment, the mass loss of residue samples ranged from 45% (FOL) to 66% (PEC) in SAFs to 44% (CFV) and 58% (RAQ) in monoculture. Decomposition constants ranged from 0.004 to 0.008 month -1 in FAS and between 0.006 and 0.008 month -1 in monoculture. FOL and CFV presented the highest N concentration and the lowest C/N and lignin/N ratio. N concentration and C/N and lignin/N ratios correlated significantly with decomposition rate (r = 0.73, -0.74 and -0.76, n = 12, P <0.001, respectively). These results suggest that the faster decomposition of FOL and CFV is due to the higher quality of these residues (high N concentration and low C / N and lignin / N ratios). N release in all cultivation systems was also higher by FOL and CFV.

The oil palm (Elaeis guineensis Jacq.) Comes from West Africa in the Gulf of Guinea region. It was brought to Brazil in the colonial period, 17th century, by slaves and its cultivation began in Brazil in the 70's, being a tropical perennial species of African origin that best expresses its production potential under high temperature, solar radiation, high precipitation and humidity. relative air. Among the main diseases that attack this palm and other palm trees of economic importance, the Red Ring disease is one of the most severe and deadly, causing the plant to death and endangering the development of plantations in the region. Thus, the objective is to evaluate the spatial and temporal distribution of Anel Vermelho and R.Palmarum in conventional palm oil plantation in the municipality of Thailand, state of Pará, in the production area of AGROPAR Farm, belonging to AGROPALMA SA, through of data obtained monthly from a Historical series from 2011 to 2018, seeking to identify the spatial distribution pattern of this pathosystem, using Geostatistics as a tool. To evaluate the dispersion of the Red Ring and R.Palmarum will be used the presence and absence method, being (1) for the presence and (0) for absence. Thus, semivariograms will be generated and the theoretical models will be tested: Spherical, Gaussian, exponential and linear (pure nugget effect). For the spatiotemporal distribution of the red ring pathosystem a centroid of each plot will be generated and the geographic coordinates (Latitude and Longitude) will be related to the accumulated occurrences of the red ring per year and to determine the dispersion of R.Palmarum the traps will be georeferenced and related to the occurrences of this insect vector. The semivariograms obtained will be submitted to the estimated Kriging for the preparation of the Patossystem dispersion maps. Thus, the objective of this work is to evaluate the spatial and temporal distribution of the Red Ring in conventional oil palm planting in Thailand-PA

The oil palm is the most important oilseed worldwide, and Al can be an abiotic factor limiting its productivity and quality, causing a decrease in the growth and development of these plants, B in turn, is a micronutrient that participates in the synthesis of the wall and cellular elongation, in the transport of carbohydrates, avoids the paralysis of the root growth, presenting great importance in the development of the roots, growth that can help to mitigate the toxic effects of aluminum, directly affecting its production and yield. In this context, the objective of the work was to study the effect of B, enabling greater growth and development from the evaluations of morphological processes, gas exchange, chlorophyll and carotenoid content in oil palm seedlings, grown under different aluminum saturations. The experiment was carried out in a greenhouse, using as substrate samples of a Yellow Latosol with a 0-20 cm layer, in a completely randomized design, 3x5 factorial arrangement, with three levels of Al saturation (m%): 50, 60 and 70%, applied in the form of aluminum chloride (AlCl3) and five doses of B: 0, 3, 6, 10.15 mg // dm³ soil in the form of H3BO3, the samples were grown in the period of 8 months. The results showed that B promoted better results when compared to treatments with the absence of micronutrient, in addition to mitigating the effect of toxic aluminum, showing greater efficiency by using water in oil palm seedlings, for the variables of MSPA, MSR and MST the amount of B to be applied for maximum technical efficiency is 0.40 mg / dm³; 2.71 mg / dm³ and 0.04 mg / dm³ of B for 70% Al saturation. Therefore, it is concluded that the biometric and gas exchange variables for oil palm seedlings were significantly influenced by saturation of Al in the soil, and B was able to mitigate the toxic effect of Al in oil palm seedlings when submitted to doses of 3 and 6 mg / dm³, according to the variable EisUA, being an essential micronutrient in the growth and development of plants.

Mining in the Carajás Mineral Province (PMC) started in the 1980s, with excavation being carried out by means of an open pit, forming mine pits and waste piles, which are revegetated to reduce negative environmental impacts. Brazilian environmental legislation, in the case of a federal conservation unit, such as the Carajás National Forest (FLONACA) - where the Carajás Mineral Complex has been installed for the extraction of iron, copper and manganese - recommends the use of exotic species cocktails / non-aggressive and easy to control commercials, and FLONACA's native forest and canga species for the revegetation of areas impacted by mining. However, the selection of native species requires the best knowledge of their growth and nutritional requirement. The objective of the present study was to evaluate mineral and organic fertilization on growth, efficiency of nitrogen use, nodulation, and the production of nitrogen compounds from two species of the genus Crotalaria, the first being Crotalaria spectabilis (commercial / exotic species from FLONACA ) used to revegetate areas impacted by mining in Carajás, and the second to Crotalaria maypurensis (native to the Carajás ferruginous canga). The latter is not yet used in revegetation activities at PMC, however, it has potential for use in revegetation due to the high production of seeds and rapid production of biomass. The experiment was conducted in a greenhouse, with two aforementioned species, which were grown under different fertilization conditions (Control - no fertilizer added; NPK; NPK + Micronutrients; NPK + micronutrients + Organic compound; PK; PK + Micronutrients; PK + Micronutrients + organic compound) constituting 7 treatments, with 5 repetitions. Carajás iron mining waste was used as a substrate for the growth of both species. After 90 days of cultivation in the treatments, biometric data, nutritional efficiency, nodulation efficiency, and quantitative analysis of amino acids and nitrogen compounds (nitrate and ammonia) were evaluated. The results obtained revealed that, regardless of the treatments applied, the commercial species showed higher plant height than the native species. In the same way, the commercial species was more responsive to the treatments used to promote greater production of roots and shoots. Specifically, the treatment NPK + Micronutrients, promoted the highest production of biomass in the commercial species, while the treatment NPK + micronutrients + Organic compost promoted greater growth in the native species. The native species showed a higher number of nodules and dry nodule mass. However, this did not reflect greater efficiency in nodulation or in the efficiency in the use of nitrogen, since the commercial species was superior in these variables. In addition, the species studied showed different responses to nitrogen compounds in their tissues. While C. maypurensis tended to have a higher concentration of nitrate in leaves and nodules, the species C. spectabilis ammonium is the predominant form of nitrogen. The results show that the species present differentiated nitrogen metabolism. Although the native species shows less growth, its use in the revegetation of mined areas in FLONACA must be taken into account by native species.

The açaizeiro (Euterpe Oleracea Mart.) is native to the Brazilian Amazon whose natural habitat is hydromorphic soil ecosystems that drain twice a day. The objective was to evaluate the floodplain systems by means of the chemical, physical and biological attributes of hydromorphic soils in areas of native açaizais, in addition to the chemical characteristics of the water quality of the river in order to contribute to the maintenance, preservation and proper management of these ecosystems. . The study was carried out in three areas of native açaizal on the Saracá Island belonging to the municipality of Limoeiro do Ajurú, in the region of Baixo Tocantins. 60 soil samples were collected with deformed structures in two pluviometric periods (n = 10) and 60 undisturbed samples (n = 20) at a depth of 0-10 cm. The deformed samples were used to determine the physical characteristics of the soil and the deformed samples were used for the analysis of texture and chemical and biological attributes of the soil, both were developed in the soil physics, chemistry and microbiology laboratories of Ufra. The micronutrients were determined in the chemical analysis laboratory of the Emílio Goeldi Museum and the chemical quality of the river water in two pluviometric periods was analyzed at the Evandro Chagas Institute. Regarding the physical-hydric attributes of the hydromorphic soil, the three floodplain areas presented a silt loam texture, good water retention in potential critics and a high index of soil aggregation, promoting these areas good structure, already taking into account the chemical attributes of the soil and water in the two pluviometric periods, the iron content in the soil was higher in the less rainy period, while manganese decreased in the same period. Calcium and magnesium increased while phosphorus and potassium did not increase significantly in relation to the two periods. The levels of metals found in the river water of the three areas are in accordance with the reference values established by CONAMA, only iron in the very rainy period in the central floodplain obtained a higher value. In relation to biological attributes, the low metabolic coefficient indicates savings in energy use and, supposedly, reflects a more stable environment or closer to its equilibrium state. The soil of the three floodplain areas has good nutrient availability, energy savings used by microorganisms and excellent soil water retention and aggregation that configures the floodplain ecosystem to natural chemical, physical and biological conditions favorable to the production and maintenance of native açaí groves and the quality of the river water considered suitable for consumption by riverside dwellers.

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Climate change can have negative effects on plant growth and physiology, inducing various abiotic stresses and, consequently, limiting productivity. Waterlogging is an environmental threat that limits crop growth and yield Ensuring productivity in adverse environmental conditions is a priority, given the need to ensure food security. 24-Epibrassinolide (EBR) is one of the most active forms of brassinosteroids that are plant steroids, involved in promoting plant growth and development. Recent studies have shown that these steroids can also act in the adaptation and tolerance of plants against various abiotic stresses. Our hypothesis was based on the damage caused by waterlogging and the possible benefits of EBR on plant metabolism. The aim of this research was to investigate the anatomical, biochemical and physiological responses of the application of EBR in Glycine max plants under waterlogging. This study used a completely randomized factorial design with two water conditions (control and waterlogging) and three concentrations of 24-epibrassinolide (0, 5 and 10 nM EBR). This research clearly demonstrated that exogenous EBR protected soybean plants against oxidative stress caused by waterlogging, which was confirmed by the improvements in the root anatomy, photosynthetic machinery and biomass. Application of EBR attenuated the negative impacts of waterlogging under Chl a, Chl b, Total Chl and Car contents, the concentration of 10 nM EBR induced increases of 14%, 47%, 19% and 111%, respectively, when compared to the waterlogging + 0 nM of EBR treatment. The results prove that pre-treatment with EBR improved the tolerance of soybean plants to waterlogging and that the application of 10 nM EBR produced better effects on biomass.

Zinc is an essential element to plants, however, in excess it can be toxic to the vegetable. Phytoremediation of soil contaminated with Zn is effective to reduce the toxic effects of this metal to the environment. Therefore, it is necessary to identify species tolerant to these conditions. Schizolobium amazonicum is an arboreal species native to the Amazon used for the recovery of degraded areas. Silicon is a beneficial element that increases plant tolerance to biotic and abiotic stresses. Therefore, the objective of this work was to evaluate the morphological, physiological, biochemical and nutritional effects of Si on young plants of S. amazonicum submitted to Zn toxicity. A 4 x 2 factorial randomized block design with four zinc concentrations (1, 150, 300 and 600 μM) and two concentrations of silicon (0 and 1.5 mM) with five replicates per 30 days was used. The nutritional status, growth, tolerance to excess zinc, chlorophyll a fluorescence and gaseous changes in seedlings were evaluated. Preliminary results show that high zinc levels reduced plant growth and nutrient uptake, but the application of Si attenuated this effect. S. amazonicum showed low translocation and moderate and high tolerance to Zn concentrations indicating that this species can be used as a phytostabilizer of this metal.conditionsTraduções de conditionSubstantivoFrequênciaacondiçãocondition, status, requirement, proviso, state, plightoestadostate, status, condition, estate, country, orderasituaçãosituation, position, condition, state, location, layacircunstânciacircumstance, condition, fact, case, instance, respectacláusulaclause, proviso, stipulation, condition, article, passageaparticularidadeparticularity, peculiarity, particular, circumstance, point, conditionaposição socialcondition, degree, state, rankoincidenteincident, incidental, scene, circumstance, passage, conditionofatofact, suit, event, truth, act, matterVerbocondicionarconditionacondicionarcondition, pack, stow, wrap, put upregularregulate, set, order, correct, condition, postdeterminardetermine, ascertain, set, define, order, prescribeestipularstipulate, date, covenant, conditionlimitarlimit, narrow, confine, bound, contain, borderDefinições de conditionSubstantivo1the state of something, especially with regard to its appearance, quality, or working order.the wiring is in good conditionSinônimos:state shape order2the circumstances affecting the way in which people live or work, especially with regard to their safety or well-being.harsh working and living conditionsSinônimos:circumstances surroundings environment situation setup setting habitatVerbo1have a significant influence on or determine (the manner or outcome of something).national choices are conditioned by the international political economySinônimos:constrain control govern determine decide affect touch form shape guide sway bias+3 definiçõesSinônimos de conditionSubstantivoweather conditionSubstantivostate circumstances fitness disorder stipulation status circumstance precondition term shapeVerboconstrain train treat improve discipline qualify+67 sinônimosVeja tambémcondition

Paraense fruit growing is constantly threatened by several phytosanitary problems, with insects belonging to the Tephritidae family (Insecta: Diptera) being among the main pests of this sector. However, despite the economic importance of these tefritids, information about the bioecology of these insects in some regions located in the Amazon biome is still scarce. Thus, our objective was to conduct a survey on the biodiversity of fruit flies and their parasitoids in the lower Tocantins microregion, Pará, Brazil. For this, passive and active collections were carried out in agroforestry yards located in the municipality of Cametá, Pará, Brazil. In the passive collection, McPhail traps were used, which were installed at 1.5m in height and used hydrolyzed protein as an attractive corn, while the active collection was carried out using guava, taperebá and star fruit, which were collected and stored in appropriate container and environment for obtaining the pupae of fruit flies and later their parasitoids. Shortly after the screening of the captured insects, the females of Anastrepha Schiner (Diptera: Tephritidae), as well as the parasitoid hymenopterans were tagged and later sent for identification at the Instituto Biológico de são Paulo. Soon after the identification of the fruit flies, the wealth, abundance and population fluctuation were determined, in addition to the niche modeling for the species with new reports for the region. As for parasitoids, the richness, abundance and influence of host fruits on the parasitism index were analyzed. Among the species found in this study, we highlight the Anastrepha zacharyi Norrbom flies, as the first report in the state of Pará, Brazil, this species being possibly endemic to the Amazon region. As for the community of tefritids associated with agroforestry yards, we find the following species; A. obliqua, A. distincta, A. striata, A. sodalis, A. leptozona and A. serpentina, the population fluctuation of these insects being influenced by the availability of hosts. Four species of parasitoids were recorded in this study; Doryctobracon areolatus (Szépligeti); Opius bellus Gahan; Utetes anastrephae (Viereck); Asobara anastrephae (Muesebeck), the first being the most abundant. Among the thefts collected, the Taperebá - Spondias mombin was the one that provided the highest rate of parasitism and the Carambola - Averrhoa carambola the lowest.

The oil palm leaf stripper caterpillars, Automeris liberia and Brassolis sophorae are considered important pests in the crop, because they cause large defoliation, reducing production at various stages of crop development. The objective of this study was to describe the biomorphometry of the leaf strippers A. liberia and B. sophorae and to evaluate the biocontrol with the fungi Isaria sp., Trichoderma sp., Metarhizium anisopliae and Beauveria bassiana, where 239 isolates were obtained from soils from different areas of palm plantation of the company Agropalma S / A. After toxicological screnning on third instar larvae of the Tenebrio molitor beetle (Coleoptera: Tenebrionidae), nine isolates, five of M. anisopliae and four of B. bassiana, were selected and evaluated again on coleopteran larvae under different concentrations. The best performance of the isolates UFRA_Ma62 (M. anisopliae) and UFRA_Bb05 (B. bassiana) at concentration 10⁸ conidia. mL^-1, which were tested on caterpillars in the laboratory and in the field. Biological results showed that the biological cycle was 85 and 137 days for A. liberia and B. sophorae, respectively. Sexual dimorphism regarding adult size and antenna difference between males and females. Statistical analyzes were performed using the Newman-Keuls test (P <0.05) using the R program. Field tests showed greater control efficiency when using the UFRA_Ma62 isolate and less cost than standard treatment with B. thuringiensis.

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The potential of remote sensing in agricultural management in the Brazilian Amazon is still little explored despite being highly promising with the evolution of sensors and the arrival of drone platforms. Especially in the detection and spatial modeling of diseases, which in recent decades has had a strong impact on the productivity of regional cultures. The detection and monitoring of disease dispersion in oil palm plantations represent major challenges for the management of this crop in Brazil. Anticipating impacts and negative trends in oil palm production, supported by remote sensing and applicable methodologies, are among the objectives of this study at the doctoral level. Oil palm plantations in the state of Pará provide inputs for the food, cosmetics, agri-energy and biofuels industries, satisfactorily supplying the Brazilian market. In recent years, several factors such as pests, diseases and severe droughts have interfered in the productivity of oil palm in the region, generating the need to adopt new techniques for detecting and monitoring these problems. In the present study, successful spectral enhancement tests (by simple reflectance and vegetation indices) were carried out to detect diseases in four oil palm plots on the Companhia Palmares da Amazônia (CPA) farm, belonging to the Agropalma SA group, in municipality of Acará, state of Pará. The results allowed the identification of expressive minimum and maximum reflectance patterns of the studied plots, correlating them with the occurrences of diseases registered in the area. Vegetation indexes were calculated from Sentinel 2A orbital images, with emphasis on the EVI index, which showed an excellent correlation with real occurrences of diseases. However, the NDVI and SAVI indices also showed good adjustments with the occurrence of diseases in the year 2017. The areas corresponding to plots L36 and H27 showed higher occurrences of diseases, based on the reflectance analysis by vegetation indices. Thus, it could be concluded that the reflectance enhancements, NDVI, SAVI and EVI obtained by orbital sensors, are efficient in detecting diseases in the plots. The results allowed the identification of diagnostic anomalies of stresses in the plots, either due to a disease or other factor, which allows decision making in a timely manner, avoiding large scale eradication in the extensive areas of commercial oil palm plantations in the region. The second analysis of the work referred to the calculation of palm oil productivity by means of orbital images, evaluating its correlation with the actual productivity and with the geostatistical zoning of the infestation by Fatal Yellowing (FA) and anomalous climatic factors. It is worth mentioning that the remote sensing productivity estimate can be used as an important support for crop forecasting, supporting the traditional methods adopted when harvesting in the field, which in turn can be imprecise, time consuming and with high cost of execution. In this context, spectral enhancement through the calculation of vegetation indices has great potential to estimate the productivity of palm oil in the Amazon. For the calculation of productivity, orbital images of the OLI Landsat-8 system for the years 2014 and 2015 were used, covering fifteen plots in the production areas of Fazenda Companhia Palmares da Amazônia (Agropalma SA) in the municipality of Acará, state of Pará. Additionally, the Agroplama SA databases, referring to local productivity and occurrences of pests and diseases, compiled between 2005 and 2015 were used. From these databases, geostatistical analyzes (dispersion of PA), productivity calculations by remote sensing and its correlation with the infestation areas. Field data referring to productivity were collected by company employees and served to correlate with results based on remote data. Based on the images of the years 2014 and 2015, the vegetation indices were derived: NDVI, EVI, SAVI, ARVI and RNDVI, and from the statistical model of linear regression, the indices and their effectiveness for calculating productivity against the measures were evaluated. obtained in the field for both years. Such index estimates were considered satisfactory for oil palm productivity, confirming the potential efficacy of orbital remote sensing for productive crop prediction.

Global soy production reached the 2017/2018 crop, the second highest production ever recorded thanks to harvests in the United States and Brazil. Among the factors that have contributed to leverage the production and productivity of this commodity, in addition to favorable soil conditions, the availability of nutrients, especially micronutrients, has been a determining factor to be considered. Essential micr-onutrients such as zinc (Zn) and iron (Fe) play a crucial role in soybean production, as they are involved throughout the crop's development cycle. However, inadequate supplies of Zn and Fe have become stress factors for culture due to the deficiency or excess of these elements in the plant. In recent years, strategies and technologies have been developed for the treatment of plants stressed by abiotic factors, among them, the application of plant steroids has been discussed as an effective and less harmful method. From plant steroids, considerable attention has been paid to brassinosteroids (BRs). In this context, the objective was to evaluate the effects of Zn and Fe in the soybean culture exposed to low/high supplies of these elements in the soil, as well as to investigate the physiological and biochemical behavior of BRs in soybean plants submitted to Zn deficiency and excess and Fe and identify the possible benefits caused by the steroid. For this, two experiments were carried out in a greenhouse. Experiment I followed a completely randomized factorial design with two concentrations of 24-epibrassinolide (0 and 100 nM EBR) and three supplies of Zn (0.2, 20 and 2000 μM Zn). Experiment II was carried out in a completely randomized design with four treatments (0 nM EBR + 250 μM Fe, 0 nM EBR + 2.5 μM Fe, 100 nM EBR + 250 μM Fe and 100 nM EBR + 2.5 μM Fe). In general, low supplies of Zn and Fe and high supplies of Zn produced deleterious effects. However, the results revealed that exogenous BRs (100 nM EBR) minimized the damage caused by Zn and Fe deficiency and by toxic Zn levels in soybean plants. In experiment I, EBR alleviated the impact produced by zinc stress on the root system by acting positively on the epidermis, endoderm, cortex, vascular cylinder and metaxylem, intrinsically improving the nutritional status in plants. EBR promoted improvements in the photosynthetic machinery of plants exposed to zinc stress, stimulating the activity of antioxidant enzymes that play crucial roles in the protection of chloroplast membranes, with positive repercussions on chlorophylls, effective quantum yield of PSII photochemistry and transport rate of PSII electrons. In experiment II, EBR maximized the Fe content in the leaf, stem and root, as well as improved the nutrient content and the metal homeostasis, as confirmed by the increased detection of Fe2+/Mg2+, Fe2+/Mn2+ and Fe2+/Cu2+ in plants with Fe deficiency. The steroid also promoted improvements in chloroplastic pigments and increased photochemical efficiency, positively regulating electron transport and reducing the negative impacts associated with PSII photoinhibition.

Soybean is a legume that is widely cultivated in many countries due to the high levels of proteins and oils contained in its grains. It is used in human and animal nutrition or for the production of medicines, industrial products and biofuel. On the other hand, salt stress is a limiting factor in crop production and it is estimated that more than 800 million hectares are affected by salinity. In this sense, the aim of this research was to evaluate the structural behavior, using root, stem and leaf variables, detailing the possible anatomical changes involved in these organs, in addition to understanding the nutritional behavior, the photosynthetic apparatus, gas exchange, antioxidant system and oxidative damage in soybean plants submitted to progressive salt stress. For this, the experiment was randomized into five treatments (0, 50, 100, 150 and 200 mM NaCl). In the root, increases in the epidermis and endoderm reveal the protective roles of these structures in plants subjected to 100 mM Na+ , which favor the reduction of the influx of Na+ . With the increase in salinity, the higher increase in the lysigenous aerenchyma minimizes the absorption of toxic ions by replacing dead cells with air spaces. In relation to the stem, increases in the cortex and pith, in the first internode in concentrations of 100 mM Na+ , alleviate the damage and oxidative stress generated by salt in the meristematic regions. In all root and stem regions analyzed in soybean plants subjected to concentrations of 50-200 mM Na+ , the metaxylem is reduced to prevent cavitation and loss of functionality of vessel elements and, these changes, maximizes the impermeability of this tissue preventing ionic flux by increase the thickness of the cell wall. In relation to leaves, progressive salt stress negatively interferes in K+ /Na+ homeostasis, nutritional content, photosynthetic apparatus and gas exchange, also increases oxidative damage and, to some extent, induces the antioxidant system and harms photosynthetic pigments. On the other hand, the impacts of salinity promote leaf anatomical changes to minimize the deleterious effects associated with Na+ . Effects such the increase of epicuticular wax in saline concentrations of 50 mM Na+ favor a lipophilic protection that prevents the loss of water through transpiration and the direct incidence of solar radiation in the epidermal cells. In addition, the improvements observed in the number of stomata, in their most elliptical form, as well as the increase in the thickness of the epidermis, up to 100 mM Na+ , evidence a strategy for the efficient use of water. Finally, this research showed that soybean plants subjected to progressive salt stress exhibited anatomical changes to minimize the deleterious effects associated with Na +.

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Iron (Fe) toxicity is one of the most frequent abiotic stresses in rice, affecting from 15% to
30% of total production. Brassinosteroids (BRs), including the 24-epibrassinolide (EBR)
regulate ion homeostasis and improve antioxidant system. The aim of this research was to
answer if the EBR can contribute to tolerance of rice plants exposed to Fe toxicity, evaluating
the possible repercussions on anatomical characteristics, nutrient concentrations, antioxidant
system, and gas exchange. The experiment was randomized with four treatments, including
two Fe supply (250 and 6250 Mm Fe described as control and toxicity, respectively) and two
concentrations of brassinosteroids (0 and 10 nM EBR, described as – EBR and + EBR,
respectively). Plants exposed to Fe toxicity and treated with EBR presented increases in
Mg2+/Fe2+, Mn2+/Fe2+, Cu2+/Fe2+ and Zn2+/Fe2+ ratios in shoot of 83%, 89%, 103% and 120%,
comparing with same treatment without EBR. This research revealed that the EBR mitigated
the deleterious effects of the Fe toxicity on rice plants, modulating the aerenchyma area, in
which this structure contribute to the formation of an oxidative barrier, Fe immobilization in
root surface. Concomitantly, this steroid increased the contents of other metals, such as
magnesium, manganese, copper and zinc, proving the influence related to metal homeostasis,
confirmed by increases in metal ratios. Plants under Fe toxicity and treated with EBR
presented increases in all enzyme activities evaluated, superoxide dismutase, catalase,
ascorbate peroxidase and peroxidase, mitigating the oxidative damages and favoring the
scavenging of reactive oxygen species. Finally, the EBR actions alleviated the negative
impacts induced by Fe excess on net photosynthetic rate and carboxylation instantaneous
efficiency, being these benefits directly related to higher electron transport and stomatal
density and indirectly linked to protection mechanism exercised by the antioxidant enzymes
on photosynthetic machinery. Therefore, our results clearly indicate that the EBR is able to
confer tolerance in rice plants under Fe toxicity.

Tectona grandis L.f is the most important economic species of the genus Tectona. Due to the reduction of its availability of natural form, there was increase in its production of planted form. An alternative to homogeneous management is the varied management, which can be implemented through precision forestry. A widely used precision tool is geostatistics. As this tool generates many maps, one way to simplify them is multivariate statistics, through principal component analysis. With the main components, it is possible to determine the management zones of an area through the algorithm "Fuzzy c-means". The objective of this work is to generate areas for the management of a teak crop with the help of multivariate statistics and geostatistics, in order to contribute to the fertilization recommendation. The work was carried out at the São Luiz farm, located in the municipality of Captão Poço, which is approximately 75 km from the municipality's headquarters. The farm has grown teak (Tectona grandis) for 20 years. A systematic sampling grid of 155 geo-referenced points was used to collect soil samples and yield. The collected samples were placed in plastic bags, identified and sent to the laboratory, for determination in the soil of pH, Ca, Mg, K, SB, Al, H + Al, P melich, B, and for the calculation of the variables ; M.O, effective CTC, CTC pH 07, m%, v%, samples of DBH, Height and volume were also determined. It was possible to fit most of the variables of the study into one of the most used semivariogram models in precision forestry. After the semivariograms were adjusted, the kriging maps of the isolated variables were made. Through multivariate statistics, the first three main components were selected, representing 79.58% of the data variability. Geostatistical analyzes were also performed on the main components. The three selected components were used to determine the management zones, through the algorithm "Fuzzy c-means". Three were the number of zones suitable for work. After the determination of the zones it was possible to relate each of the 155 observations of the soil variables to one of the zones. Zone 1 corresponded to 9 of the samples, zone 2 to 43 and zone 3 to 103, then a variance analysis was performed to obtain the means of the soil variables in each of the zones and, afterwards, these averages were submitted tukey test so that it is possible to see if they are statistically different. The application of the cluster analysis showed different results from the homogeneous analysis. Zone 01 was the one that showed the best soil fertility results. Through cluster analysis it is possible to obtain results not shown by univariate statistics.

In cultivated pasture, the plants development is directly related to soil attributes and its spatial variability, and due to its intensive management, has caused levels of soil degradation and consequent decrease in pasture yield. It is also observed that there is a shortage of studies in Southeast region of Pará State in relation to use of geostatistics as a tool in study of relation of spatial distribution of soil attributes and forage quality in cultivated pasture systems, in which could contribute to more profitable and environmentally sustainable livestock. Based on this, the aim of study were to evaluate the spatial variability of soil attributes and the morphogenic behavior of forage in grazing under a rotational system of buffaloes. The study was carried out in Parauapebas city, State of Pará, Brazil, in a pasture grown forage Panicum maximum (Jacq.) cv. Mombasa, in a rotational grazing system with buffaloes, established five years ago. An experimental mesh was installed for data collection established with spacing of 10 x 10 m, containing 392 sampling points distributed in an area of 34300 m2. The soil attributes analyzed were soil mechanical resistance to penetration (SMRP), soil water content (U%) and soil hydrogenation potential (pH). The qualitative parameters of forage were: height (H), number of tillers (NT), dry mass (DM), stem / leaf ratio (SL ratio), leaf area index (LAI). In superficial layers of soil (0-0.2m), the physical attributes of soil SMRP and pH showed a structure of spatial dependence of moderate to strong in pickets. A (U%) showed weak spatial dependence and high correlation with pH. Forage height and number of tillers had moderate to strong spatial dependence and low correlation with soil attributes.

Pseudomonas is a genus of gram-negative bacteria frequently found in soil or in symbiotic relationship with plants. When these bacteria occur into internal tissues of plants, they are denominated endophytic bacteria. Among them, some bacteria are known as Plant Growth-Promoting Bacteria (PGPB), since they are able to produce phytostimulants, biofertilizers and biocontrol substances. Previous studies have identified Pseudomonas bacteria (isolates Pt12 and Pt13) associated with roots of Piper tuberculatum, a piperaceae occurring in the Amazon region with known resistance to infection by Fusarium solani f. sp. piperis, causal agent of fusariosis of  black pepper (Piper nigrum L.). The present study aims to characterize these two isolates regarding their abilities to produce siderophores and indoleacetic acid (AIA) and solubilize inorganic phosphates, as well as to detect DNA sequences of proteins potentially related to biosynthetic pathways of these substances. Our results showed that isolates Pt12 and Pt13 were able to produce AIA, especially in the presence of high concentration of tryptophan, indicating that they are IAA-producing bacteria by tryptophan-dependent biosynthetic pathways. The isolate Pt12, previously identified as a Pseudomonas putida, was also able to produce siderophores when cultivated on LB (Luria-Bertani) and TS (Tryptone Soybean) media, and analyzed through CAS (Chrome Azurol S) assay. In addition, when cultivated in NBRIP medium the isolate Pt12 was able to solubilize tri-calcium phosphate, which was evidenced by detection of transparent halos around the bacterial colonies.

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Coconut farming has great socio-economic importance, especially for regions
North and Northeast, generating employment and income for inhabitants of these regions. This one
The objective of this study was to evaluate the effects of defoliation on
Cocos nucifera seedlings, performed at different levels. Four
treatments: without defoliation; defoliation of 30%; 60% and 90%. Were
measured gas exchange variables: Liquid assimilation rate of CO2 (A)
Stomatal conductance (Gs), transpiration rate (E) and intercellular carbon ratio and
atmospheric carbon (Ci / Ca) in addition to growth variables of two materials
the Brazilian dwarf coconut and the PB 121 Hybrid.
variance at the end of the experiment, where the results show that for the PB 121 hybrid,
the gas exchange variables did not obtain a significant difference, except the relation
Ci / Ca that obtained the highest rates for the control treatment. On the other hand, the
The net assimilation of CO2 was significantly lower for treatments of 60 and
90% of defoliation of the Brazilian dwarf coconut. The treatment of 30% of
hybrid PB 121 had its leaf area equal to the control treatment, showing its
foliar recovery, however, the T60 and T90 were significantly lower. In case
of Brazil's green dwarf, no level of defoliation was able to recover its area
leaf, being, all proportionally inferior to the control treatment. Plants that
suffered higher percentage of defoliation, presented lower height, for the two materials
genetics. It was concluded that the artificial defoliation influenced negatively, the
growth of coconut seedlings, not reaching satisfactory parameters for the field.

A

The present work had as objective to verify the potential of control of aqueous extracts of plants native or occurring in the Amazon Region, for the control of the key pest aphid in growing vegetables. Field interviews were conducted with producers of vegetables located in two municipalities in the Northeast of Paraense, in order to obtain information about pests, the main control methods, and the use or knowledge of plants with insecticidal effect. In addition, the effect of aqueous extracts of plants occurring in the Amazon region on nymphs and adults of aphids was evaluated. The leaves were dried in an oven at 50ºC for 48h and crushed to obtain powder. The treatments consisted of 10% (g-mL-1) vegetable extracts of cipó de alho, melão de São Caetano, Quina and distilled water (control). The solutions obtained were sprayed on brassica discs (Brassica oleracea var. Acephala), placed on filter paper in Petri dishes containing 10 aphids, followed by the plates were sealed with transparent plastic film, punctured with an entomological pin and held in camera conditioned air type BO D (25 ± 1ºC, 70 ± 5% RH and 12h of photophase). The experimental design was completely randomized and the natural mortality was corrected by Abbott's formula. Among the interviewees, 95% reported having some type of problem with the occurrence of pests in their area of cultivation. The number of dead nymphs and adults were counted 24 and 48 h after spraying, the results were submitted to analysis of variance and the means were compared by the Tukey test at 5% probability. Among the pests that cause the most damage to cultivated vegetables, are caterpillars (Lepidoptera), packs (Orthoptera), leafhoppers, slugs, whiteflies (Hemiptera, Aleyrodidae and aphid (Hemiptera, Aphididae). The insecticidal effect of the extract of quinine was observed in aphids in the nymph and adult phase, and the extract of garlic cichó had an insecticidal effect only in the phase The number of insects killed after spraying with melão de São Caetano extract did not differ from the control treatment. The extract of quinine showed an insecticidal effect on the aphid, a key pest in vegetables, in the nymph and adult phases.

The emerging demand for reducing dependence on mineral fertilizers and the need for sustainable agriculture development point to the use of microorganisms as a viable alternative to the producer in order to reduce mineral fertilization. The objective of this study was to evaluate the potential of nine microbial isolates to promote growth through two methods of inoculation (irrigation and immersion) in emerald grass seedlings. The experiment was carried out in a completely randomized design in a 2x8 factorial scheme, with four replications. The treatments consisted of two methods of application (Rega and Immersion) x 9 microorganisms isolated and in control combination (T1 (water / control), T2 (Pseudomonas fluorescens- BRM32111), T3 (BRM32113), T4 (R-92) , T5 (R-61), T6 (R-58), T7 (mixtures of Pseudomonas fluorescens (BRM32111) and Burkholderia pyrrocinia (BRM32113) and T8 (mixtures of Trichoderma asperellum-UFRA-T.06, UFRA-T.09 , UFRA-T.12 and UFRA-T.52) .The irrigation application method, independent of the isolate, provided a 64% increase in total biomass, whereas by immersion the increase was 35% in relation to the control. In this study, the BRM32111 and BR32113 isolates measured increases of 104% and 122%, respectively, and the root dry mass and plant height variables were sufficient to explain the highest percentage of variation in the data. of 156% and 92% in dry mass of root and height of plants, respectively, in relation to the control. The rhizobacterium BRM32113 proved to be competent in inducing the growth of the emerald grass plant and could be inserted into an ecologically sustainable nutritional management program with potential for commercial use.

The Amazon is an important source of natural resources, rich in biodiversity, water resources and minerals, providing important ecological services to the world, such as storing fresh water and minimizing the effects of global warming. Therefore, studies demonstrating the dynamics of potentially toxic elements (PTEs), such as metals and metalloids in soil, are of great relevance. The identification of the concentrations of these elements is indispensable for control and decision making in order to avoid environmental impacts and the health of plants and animals, including humans. The concentration of PTEs in Piriá Watercourse in soil samples under native forest and tailings of different types of gold (Au) exploration, as well as chemical and physical attributes, and their relationships with PTEs were determined. In order to evaluate the degree of pollution, the enrichment factor (EF), contamination factor (CF), geoaccumulation index (Igeo), pollution load index (PLI), potential ecological risk (PER) and ecological risk multi-element combination (IR). High levels of PTEs were found in the rejects of the Au exploration areas, values higher than those of research (VI), defined by CONAMA, which characterizes polluted areas. The concentrations of As, Co, Cr, Ni, and Sb. Of the 18 elements evaluated only Ag, Cd and Si are at levels corresponding to the natural values, ie, soil quality reference values (QRVs) for the state of Pará. are above VI, while Hg and Mn are above the prevention values defined by CONAMA, and above the world average. There was enrichment of the PTEs As, Ni, Sb, Ag and Mo. All the elements presented moderate to highly contaminated CF in at least one of the garimpos, demonstrating contamination by EPTs. The PLI indicated deterioration of the soil in all the mines. It featured PER for various elements in all prospects, as well as extremely high RI for a large number of PTEs. From the pollution rates determined for the artisanal mining areas we can infer the need for immediate actions for remediation, aiming at reducing the environmental risks and the health of the local population.

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The availability of B in the soil can influence the water condition of the plants in different ways, so that the concentration of this element can be a fundamental factor for the plant to be able to attenuate the effects of the water restriction. Thus, the supply of B can favor the water relations of plants, improving the absorption of water and nutrients, transport through the xylem, and relieve the wilt of plants. In this context, the objective was to evaluate the effects of B doses and their influence on gas exchange in the vegetative phase; the fluorescence of chlorophyll a, gas exchange, growth and productivity in the reproductive stage of soybean cultivated with different water contents in the soil. For this, a greenhouse experiment was carried out in two different phases. In the first phase, treatments were 4 doses of B (0.0, 1.5, 3.0 and 6.0 mg dm-3) and five replications in randomized blocks. In the second, the treatments consisted of the combination of the same doses of B of the first phase and three levels of water in the soil [60, 80 and 100% of the moisture in the field capacity (Ucc)], in a 4 × 3 factorial scheme, with five replications distributed in a randomized block design. The results revealed that: i) the application of B promoted improvement in gas exchange by stomatal control, greater photosynthetic activity and better osmotic adjustment; ii) the B supply in plants under 60% Ucc promoted greater photosynthetic efficiency due to improvements in the photochemical phase, evidenced by the chlorophyll a fluorescence; (iii) The application of B contributed to improving the efficiency of water use, reducing water loss through transpiration and producing more dry matter per gram of transpired water; iv) the supply of B in condition of water restriction promoted an increase in biomass production and grain yield

O açaizeiro (Euterpe oleracea Mart.) é uma palmeira nativa da Amazônia e de grande interesse econômico no Brasil e no mundo. O Brasil é o maior produtor mundial do fruto de açaí, sendo o estado do Pará o maior produtor nacional. Essa produção era destina ao consumo local, porém a conquista de novos mercados e o aumento nas exportações estimulou a expansão dos plantios comerciais em terra firme. As crescentes emissões de gases relacionados ao efeito estufa deverão influenciar a temperatura na terra e o estresse térmico leva a uma série de alterações fisiológicas, bioquímicas e no crescimento de plantas. Portanto caracterizar o efeito isolado da alta temperatura no status hídrico, trocas gasosas, fluorescência da clorofila e crescimento de mudas açaizeiro, bem como avaliar indicadores bioquímicos de estresse relacionados ao metabolismo do carbono, dentre outros. Além disso diferentes materiais genéticos de açaizeiro apresentam diferentes tolerâncias ao estresse térmico. Avaliando-se o comportamento fisiológico de diferentes materiais vegetais de açaizeiro submetidos à alta temperatura .

A pimenteira-do-reino (Piper nigrum L.), pertencente à família Piperaceae, é a especiaria mais importante e difundida no mundo. Esta cultura é originária do sul da Índia e hoje é extensivamente produzida nas regiões tropicais. O Brasil é um dos mais importantes produtores de pimenta-do-reino, sendo o Estado do Pará o principal produtor nacional, responsável por aproximadamente 66% dessa produção. No entanto, a produção brasileira de pimenta-do-reino vem declinando drasticamente, em 47,28% de 2006 a 2014. Esse fato está ligado principalmente a doença causada pelo fungo Fusarium solani f. sp. piperis, que provoca a fusariose, que tem causado sérios prejuízos na produção de pimenta-do-reino na região amazônica. Enquanto as cultivares de pimenteira-do-reino são susceptíveis a esta doença, algumas piperáceas de ocorrência na região amazônica apresentaram resistência à infecção pelo patógeno. Entre estas, na espécie Piper tuberculatum Jacq., conhecida com pimenta de macaco, foram identificadas bactérias endofíticas do gênero Pseudomonas, isolados Pt12 e Pt13 (Pseudomonas putida e Pseudomonas sp., respectivamente) que inibiram o crescimento do F. solani f. sp. piperis em condições in vitro em 38,96% e 55,31%, respectivamente. Sabendo-se que as bactérias endofíticas colonizam os tecidos internos das plantas e podem impactar positivamente no crescimento e no desenvolvimento do seu hospedeiro, o objetivo principal deste trabalho foi estudar a interação da pimenteira-do-reino com bactérias Pt12 e Pt13, para verificar se esses endófitos podem atuar sobre a planta por meio de alterações fisiológicas e otimizando a absorção de nutrientes do solo, contribuindo, desta forma, para a promoção do crescimento e desenvolvimento vegetal. Sendo assim, buscou-se avaliar as plantas inoculadas com as bactérias Pt12 e Pt13 em termos morfofisiológicos e de biomassa. Nos ensaios para avaliar os parâmetros morfofisiológicos e de crescimento as plantas foram inoculadas apenas com o isolado Pt13, onde foi observada influência positiva e significativa nos parâmetros fisiológicos das plantas inoculadas, como trocas gasosas e clorofila total. O crescimento e a biomassa seca neste ensaio, também, foram influenciados pela interação, onde foi observado incremento da massa seca da raiz, expansão da área foliar e área foliar específica em plantas inoculadas em comparação com as plantas controle. Em outro ensaio, as plantas de pimenteira-do-reino foram submetidas a três níveis de inoculação: plantas inoculadas com Pt12, plantas inoculadas com Pt13 e plantas não inoculadas, associando estes grupos a diferentes fontes de fósforo (Arad, superfosfato simples e superfosfato triplo e um controle sem adição de fósforo), compondo um fatorial 3x4x5 (3 níveis de inoculação x 4 tratamentos com fósforo x 5 repetições). Foi observado pelo modelo do efeito linear misto uma interação entre os níveis de inoculação das plantas e os tratamentos com fósforo. Os resultados mostraram diferenças significativas entre todos os níveis de inoculação das plantas para todas as variáveis estudadas (altura, diâmetro do caule, número de folhas, área foliar, área foliar específica, massa seca da parte aérea, da raiz e total), com exceção da razão raiz parte aérea. Com relação aos tratamentos com fósforo, somente para o diâmetro do caule não foram observadas diferenças significativas. Estes resultados mostram que as bactérias endofíticas do gênero Pseudomonas isolados Pt12 e Pt13, apresentam potencial para promoção do crescimento em plantas de pimenteira-do-reino, por meio do melhoramento nos processos fisiológicos e do crescimento e desenvolvimento, facilitando a absorção de nutrientes para esta espécie vegetal.

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A matéria orgânica atua como um forte agente de agregação das partículas do solo, assim, a análise granulométrica de solos com alto conteúdo de matéria orgânica requer o pré- tratamento para sua remoção a fim de favorecer a dispersão das partículas. Solos classificados como Terra Preta Arqueológica (TPA), em geral, são ricos em material orgânico recalcitrante, de difícil oxidação. Assim, a hipótese do presente estudo é de que o procedimento padrão para análise granulométrica não é adequado para estes solos. O objetivo do trabalho foi determinar a granulometria de doze sítios arqueológicos, classificados como TPA, pelo método padrão da pipeta, com e sem pré-tratamento para remoção da matéria orgânica utilizando peróxido de hidrogênio. Os sítios estão localizados no município de Vitória do Xingu-PA, e as amostras, com estrutura deformada, foram coletadas na profundidade de 0,10-0,20 m. Também foram obtidas amostras de áreas adjacentes (ADJ) à cada sítio para fins de comparação. A proporção das frações de argila, silte e areia, variaram entre a TPA e ADJ para cada sítio assim como com e sem o tratamento para remoção da matéria orgânica. Devido à grande variabilidade observada para cada fração granulométrica, dentro do mesmo sítio e entre os sítios, com e sem o pré-tratamento com peróxido de hidrogênio, conclui-se que o método padrão de análise textural, de fato, carece de maior investigação com relação a sua eficácia para determinação da textura em solos de TPA.

O sistema de manejo adotado e o tempo de cultivo influenciam a dinâmica e disponibilidade do fósforo (P), promovendo mudanças nas formas com que este nutriente se acumula no solo. Objetivou-se com este trabalho avaliar as mudanças em longo prazo nas frações e labilidade de P em uma cronossequência de cultivos sob SPD na Amazônia Oriental. O estudo foi conduzido no município de Paragominas, sudeste paraense, em área sob cronossequência de cultivos com o SPD, utilizando-se o delineamento experimental inteiramente casualizado, em parcelas subdivididas. As parcelas foram constituídas pelos sistemas de manejo: SPD com 9 (SDP9), 11 (SDP11), 13 (SPD13), 14 (SPD14) e 15 (SPD15) anos de adoção, mais uma área sob sistema convencional de cultivo (SC) e uma com vegetação nativa (VN); as subparcela corresponderam às profundidades (0-10, 10-20, 20-30 e 30-40 cm). As amostras de solo foram submetidas ao fracionamento químico do P e classificadas em: P lábil (Pi_RTA, Pi_BIC e Po_BIC), P moderadamente lábil (Pi_Hid0,1, Po_{Hid0,1 e} Pi_HCl) e P não lábil (Pi_Hid0,5, Po_Hid0,5 e P_residual) e em fósforo orgânico (Po) e fósforo inorgânico (Pi). Os sistemas de manejo do solo apresentaram capacidade diferencial de acumulação de P. Nas áreas sob SPD, o P é acumulado na camada superficial e drasticamente reduzido com a profundidade, enquanto que no SC essa redução é menos pronunciada. Até 20 cm de profundidade, houve aumento do teor de P lábil (fração disponível para biomassa), em função do tempo de adoção do SPD; sendo o SPD, independente do ano de adoção, superior ao SC e VN. O mesmo foi observado para o P moderadamente lábil. Independentemente do sistema de manejo e profundidade, a fração não lábil de P foi a preferencialmente acumulada no solo, o que sugere a alta capacidade de adsorção desse solo. As frações orgânicas foram as preferencialmente acumuladas no SPD e VN, e as frações inorgânicas no SC. Nas camadas 0-10 e 10-20 cm, todas ás áreas sob SPD apresentaram valores de Pi superiores ao SC. Considerando a camada 0-10 cm, houve aumentos significativos no conteúdo de Po, em função do tempo de adoção do SPD. A fração Pi apresentou comportamento semelhante, porém com valores absolutos em menor magnitude. O P-total (obtido pela soma das frações) apresentou teores significativamente elevados no SPD, independente do ano de adoção, comparativamente ao SC.

Os biochars têm caracteristicas diferentes em função do material de origem e da temperatura de pirolise. Tem sido utilizado como condicionador de solos e para imobilização de metais, além do aproveitamento ecologicamente correto de resíduos orgânicos, pelo elevado potencial de sequestro de carbono. O objetivo foi caracterizar e avaliar a capacidade de adsorção de Cd e Cu de biocarvões de caroço de açaí, tegumento de castanha-do-Brasil e torta de palmiste. Os biocarvões de caroço de açaí (BA), tegumento de castanha-do-Brasil (BC) e torta de palmiste (BT) foram produzidos em quatro temperaturas de pirólise (400, 500, 600 e 700 ºC) a uma taxa de aquecimento de 3,3 ºC min^-1. Foi avaliado o rendimento, teor de cinzas, pH, condutividade, capacidade de troca de cátions (CTC), infravermelho (FTIR), termogravimétricas (TGA), microscopia de varredura (MEV-eds) e análises elementares (CHNSO). Foi determinada a capacidade de adsorção de Cd e Cu individual e competitiva dos biocarvões. Os teores de cinzas, pH e condutividade e cátions básicos aumentaram com o incremento da temperatura de pirólise. Os BA apresentaram os maiores valores de CTC enquanto os BT apresentaram os maiores teores de cinzas, cátions básicos e pH mais alcalinos. Os teores de H, N e O reduziram com o incremento de temperatura, comportamento oposto foi observado para o C. A estabilidades térmicas/químicas e as propriedades físicas de superfícies foram encontradas nas pirólises de 600 e 700 ºC, que por sua vez apresentaram a maior capacidade de adsorção de Cd e Cu. Os biocarvões adsorveram mais Cd em relação ao Cu e na adsorção multimetal adsorveu menos metais comparado a adsorção individual, devido a competição. Os BC’s adsorveram mais cadmio comparado a BT’s e BC’s (9,67 , 9,51 , 8.88 mg kg^-1) respectivamente. O BT produzido na pirolise de 700 ºC adsorveu mais cobre comparado aos BA e BC na mesma temperatura (6,99 , 6,51 , 5,44 mg kg^-1) respectivamente. A temperatura de pirólise de 700 ºC foi a que proporcionou as melhores propriedades físico-químicas e as maiores capacidades de adsorção de Cd e Cu para todos os biocarvões. Biocarvões derivados de BA, BC e BT apresentam potencialidades para remediação de áreas contaminadas por Cd e Cu.

A palma de óleo é a principal fonte de óleos vegetais do mundo. Sua produção requer elevadas doses de fertilizantes para garantir sua produção de cachos, entretanto, informações sobre as exigências nutricionais de materiais genéticos híbridos são escassas. Desse modo, o objetivo foi determinar o teor, a partição e a exportação de nutrientes, em cachos de fruto fresco de híbridos interespecíficos (HIE) de palma cultivar BRS Manicoré, em diferentes idades de plantio. Foram amostrados cachos maduros de HIE de palma cultivar BRS Manicoré, em plantas com 3, 5 e 8 anos de idade. OS cachos foram coletados em plantios comerciais de alta produtividade do Grupo Marborges, em Moju, Pará, no período de agosto a outubro de 2015. Cada cacho coletado foi separado em três compartimentos: Pedúnculo, espiguetas e frutos, e pesados para determinar a massa fresca. Posteriormente, os compartimentos foram colocados em estufa a 65°C, até atingir massa constante, para determinação da massa seca. Por fim, as amostras foram moídas e procedeu a análise química para determinação dos teores de macronutrientes. A quantidade de nutrientes exportada em kg ton^-1 de fruto fresco, não apresentou diferença entre as idades, foram exportados, em média: 3,8 kg de N; 0,7kg de P; 4,9 kg de K; 1 kg de Ca; 0,8 kg de Mg e 0,6 kg de S. Parte dos nutrientes exportados tem o potencial de retornar ao campo via cacho vazio (Pedúnculo + espiguetas). A porcentagem de nutrientes contida no cacho vazio em relação ao cacho cheio (Pedúnculo + espiguetas + frutos) foi de: 22% de N; 23% de P; 65% de K; 30% de Ca; 23% de Mg e 21% de S. Os resultados obtidos contribuem para fornecer uma alternativa para recomendação de fertilizantes em plantios de HIE cultivar BRS Manicoré, com base na exportação de nutrientes vis cacho.

Foi realizado o zoneamento de risco climático para a cultura do feijão-caupi no nordeste do Estado do Pará. Utilizou-se o modelo SARRA (Système d'Analyse Régionale des Risques Agroclimatologiques) calibrado com dados de experimentos conduzidos entre 2013 e 2016 no município de Castanhal, PA. As áreas de baixo risco climático foram definidas como aquelas que apresentaram índice de satisfação das necessidades de água (WRSI – water requirement satisfaction index) maior ou igual a 0,5 para pelo menos 80% dos anos onde o plantio foi simulado. Os resultados revelam que o período seguro para a semeadura em toda a região vai do final de dezembro ao final de abril. Além disso, os períodos que vão de meados de outubro ao início de maio, meados de novembro ao final de maio e final de dezembro a meados de junho compreendem, respectivamente, os períodos de menor risco para o cultivo do feijão-caupi nos municípios abaixo de 4° S, entre 2° S e 4° S e acima de 2° S, dentro da região em estudo.

Os sistemas de manejo do solo e o tempo de implantação provocam mudanças nas propriedades biológicas do solo, considerando a natureza dinâmica dos microorganismos do solo. Nesse contexto, o estudo sobre os indicadores biológicos fornece subsídios para a avaliação do impacto dos sistemas sobre o solo, o qual está relacionado aos processos ocorrentes no ecossistema e que depende da sustentabilidade em longo prazo. Objetivou-se avaliar as transformações ocorridas nos indicadores biológicos em razão do tempo de implantação do sistema plantio direto (SPD) na Amazônia Oriental. Para tanto, estudos complementares foram conduzidos, para avaliar a influência do SPD em longo prazo sobre o teor e a dinâmica de N_total, N_mic e N_min (Cap. I) e a avaliação multivariada dos indicadores biológicos (Cap. II) de um Latossolo Amarelo na Amazônia Oriental. Para isso, no Município de Paragominas (PA), selecionaram-se áreas sob SPD com 4 (SPD4), 6 (SPD6), 10 (SPD10) e 12 (SPD12) anos, uma área sob sistema convencional (SC) e outra sob vegetação nativa (VN). Foram coletadas amostras nas profundidades de 0-5, 5-10 e 10-20 cm, em duas épocas do ano. Utilizou-se delineamento inteiramente casualizado, em parcelas subdivididas, com quatro repetições. Para atender o Capítulo I, foram quantificados os teores de N_total, N_mic, NO₃^- e NH₄⁺ no solo. Foram estimadas as taxas mineralização (TLM) e nitrificação do solo (TLN) e avaliada a relação N_mic:N_total. Para o Capítulo II, foram determinados, em adição, o carbono orgânico (CO), C-BMS e a respiração basal do solo. Para o cap. I, os resultados mostraram que o N_total foi pouco alterado com o incremento do tempo de SPD, não apresentando diferença entre as idades avaliadas. Nos solos sob SPD, o N_mic tende a ser incrementado, preferencialmente, na camada superficial (0-5 cm), sendo os sistemas SPD10 e SPD12 os maiores contribuintes dessa fração no solo.  De maneira geral, O SPD incrementou maiores teores de N-NO₃^- e N-NH₄⁺ no solo em relação ao SC, com destaque para o SPD10 e SPD12 que foram semelhantes à VN, evidenciando a influência do tempo do sistema sobre a ciclagem do N. Para o Cap. II, dois CPs foram selecionados que juntos explicam 81% da variabilidade total dentro do conjunto de dados.