Effects of rizobacteria on the promotion of growth and control of phytopatogens in paricá seeds

Abstract

The Paricá (Schizolobium amazonicum Huber ex Ducke) is considered a species of great potential for timber production, due to its rapid growth, excellent adaptability and the quality of the timber. However, little is known about its development using rhizobacteria in the seedling phase. Therefore, the objective of this work was to evaluate the control of pathogens in paricá seeds and the promotion of growth induced by rhizobacteria. Thus, two plant growth-promoting rhizobacteria isolates, Pseudomonas sp. and Burkholderia sp..The experiment was conducted at the Microbiology and Health Laboratory and in a greenhouse at the State University of the Tocantina Region of Maranhão. The experimental design used was completely randomized, with four treatments and five replications. The tested treatments were: non-microbiolized seeds (T1); microbiolized seeds with Pseudomonas sp. (T2); microbiolized seeds with Burkholderia sp. (T3); microbiolized seeds with Pseudomonas sp. and Burkholderia sp. (T4). For the seed sanity test, 400 seeds were used for the analysis of phytopathogens, while for the in vitro test, 200 seeds were submitted to microbiolization with rhizobacteria. 200 seeds were used in the greenhouse, and the samples were analyzed for germination at 10, 20 and 30 days, plant height, root length, basal diameter, fresh shoot and root biomass and dry shoot biomass and root with 30 days. Fungal species were identified: Penicillium sp., Aspergillus flavus, A. glaucus, A. niger, and Trichoderma sp. The T4 treatment showed efficiency in the total reduction of the fungal incidence in paricá seeds. Positive correlations were found between the control parameter of phytopathogens in paricá seeds and the use of rhizobacteria, although in the greenhouse the inoculation of rhizobacteria did not significantly promote seedling growth.