SEEDLINGS OF Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby BIOSTIMULATED WITH ENDOPHYTIC FUNGI NATIVE FROM THE EASTERN AMAZON
Keywords: forest seedlings, microorganisms, biostimulated, growth prom
Paricá is a species native to the Amazon region, used to reduce the exploitation of native forests, increase timber production and ecological services, and is widely cultivated in the state of Pará. The indiscriminate use of chemicals in production systems can result in environmental contamination. Therefore, seedling production is gaining prominence with the aim of reducing the use of chemical inputs. The use of growth-promoting microorganisms assists in the production process of forest seedlings and emerges as a sustainable alternative, meeting the commercial demand for high-vigor and high-quality seedlings. Therefore, the objective of this study was to evaluate the efficiency of growth-promoting strains of fungi native to the Amazon region in paricá seedlings, increasing their hardiness and reducing the time they remain in the nursery, in addition to attenuating the use of chemical inputs. Two seedling production cycles were carried out in a nursery at the Federal Rural University of the Amazon, Pará, Brazil, during the dry season and the Amazon rainy season. The parameters obtained were biometric with the variables height, stem diameter, number of leaves, robustness index, biomass with the variables dry mass of the aerial part and root, and Dickson quality index, biochemical parameters for sugar, starch and nutritional contents of the leaves and physiological, evaluating the seedlings by means of the infrared analyzer, obtaining the variables net assimilation of CO2, stomatal conductance, internal carbon concentration, transpiration, among others. This study is the first to report the use of native strains of Beauveria bassiana, Metarhizium anisopliae and Trichoderma asperellum in paricá seedlings, showing benefits in the growth of the seedlings. It was possible to conclude that biostimulation with strains of fungi native to the Amazon region promoted growth, accumulation of biomass and improvement of physiological parameters when inoculated with the Mix T. asperellum and B. bassiana in the two production cycles. Furthermore, the rainy season influenced the shorter nursery time, allowing for seedlings with greater hardiness after 60 days, with the native strain B. bassiana being the most suitable for use in this season. Future studies are needed to confirm the efficiency of these isolates in definitive plantings.