GROWTH PROMOTION IN COCOA SEEDLINGS WITH THE USE OF ENDOPHYTIC BACTERIA ASSOCIATED WITH ROCK DUST
Cocoa, Growth promotion, Rock dust, Microorganisms.
This work aimed to analyze the growth promotion of cocoa seedlings inoculated with endophytic bacteria from isolates namely: Bacillus 24, Bacillus 163, Bacillus 144 and Bacillus 03 from the collection of the Agricultural and Forestry Phytopathology Laboratory (LABFITO) of the Federal University of Pará, Altamira University Campus, associated with rock powder composed of Diabásio Penetecaua, extracted from Km 85 of the Transamazônica Highway in the municipality of Medicilândia-PA. Concomitantly with the implementation of the experiment, morphological characterization of the bacteria, biochemical tests and the production of indole-3-acetic acid (IAA) and water deficit were carried out. The experiment has been conducted in a nursery, in the town of Ramal das Chácaras, municipality of Vitória do cocoa seedlings grown in 280 ml tubes. Two tests will be developed, the first being to choose the best substrate and the best isolates of endophytic bacteria. The second test to evaluate growth promotion using the best substrate/endophytic bacteria with and without rock dust. For trial 1, treatments in progress are organized as follows: T1-absolute control, with substrate 100% of the inputs; T2-control, with 70% osmocote and 50% Yorin (modified substrate); T3-Bacillus 24 + 100% substrate; T4-Bacillus 24 + modified substrate; T5-Bacillus 163 + 100% substrate; T6-Bacillus 163 + modified substrate; T7-Bacillus 144 + 100% substrate; T8-Bacillus 144 + modified substrate; T9-Bacillus 03 + 100% substrate and T10-Bacillus 03 + modified substrate. For trial 2, the treatments consisted of using the best substrate together with the two best endophytic bacteria, both chosen in trial 1 combining treatments with and without rock dust. After planting, daily manual watering has been carried out, as well as monitoring the development of the seedlings. The parameters analyzed will be: total plant height, stem diameter, number of leaves released, date of leaf issue, leaf area. Analysis of shoot biomass, root biomass and total biomass will also be carried out, as well as nutritional analysis and chlorophyll fluorescence, gas exchange, hormones and analysis of the architecture of the root system. The experimental design used will be completely randomized - DIC and the data obtained will be tabulated and subjected to statistical analysis using the Tukey test at 5% probability and regression analysis using the software R version 4.0.3. Regarding the results of the morphological and molecular analyses, the analyzed isolates presented a set of functional activities that can be explored to improve plant growth, through the degradation of proteins, starches, nitrogen fixation, IAA production and resistance to stress. water with variations between isolates. The conclusion of the field experiment is expected to show that the microorganisms together with the rock dust accelerate the growth of cocoa seedlings, reducing the time the seedlings spend in the nursery.