POTENCIAL DA UTILIZAÇÃO DE Bacillus amyloliquefaciens NA INIBIÇÃO DA ECLOSÃO DE JUVENIS DE SEGUNDO ESTÁDIO DE Meloidogyne

Abstract

Meloidogyne javanica represents an important pathogen, responsible for significant losses in several agricultural crops. The present study aimed to evaluate the effect of using the bacterium Bacillus amyloliquefaciens on the hatching of second-stage juveniles of the nematode. The experiment was conducted under controlled conditions, with 200 eggs in test tubes, kept in the dark at a temperature of 26 ºC for 7 days in the Nematology Laboratory. The inoculum of M. javanica was obtained from gilo roots, processed according to the methodology of Bonetti and Ferraz (1981). A completely randomized design was used, with five treatments and five replications, totaling twenty-five experimental units. The treatments consisted of: T1 (water), T2 (10%), T3 (20%), T4 (40%), and T5 (50%) of bacterial suspension. The strain of B. amyloliquefaciens was cultured in Nutrient Agar medium and subsequently in liquid Tryptone Soy Broth (TSB) medium for 24 hours. Counts of eggs and hatched juveniles (J2) were performed using a light microscope at 100× magnification, seven days after the experiment setup, and the data were subjected to analysis of variance, Scott-Knott test, and linear regression analysis. The results demonstrated a significant effect of the treatments, with an average reduction of 54.81% in J2 hatching at the concentration of 40%. A dose-dependent relationship was observed up to the 40% level, above which there was no significant gain in efficiency. It is concluded that B. amyloliquefaciens shows potential as a biological agent in the management of M. javanica, and may contribute to sustainable strategies for the control of phytonematodes in agricultural systems. Experiments under greenhouse and field conditions should be carried out to confirm the results.