Liquid Bacillus subtilis Formulation in Rice for the Control of Meloidogyne javanica and Lettuce Improvement

Abstract

Aim: To develop a liquid formulation based on Bacillus subtilis-34 using rice to evaluate the shelf life under refrigerated and room conditions and to evaluate the effect of different addition times of the formulation on the control of Meloidogyne javanica and growth of lettuce plants. Statistical Design: The design was completely randomized, with five treatments and eight replicates. The results were submitted to analysis of variance and the means were compared by the Scott Knott test with 5% error probability. Location and Duration of the Experiment: The experiment was set up during the period from 02/13/2018 to 03/20/2018 in a greenhouse located at the State University of Montes Claros, municipality of Janaúba, MG, Brazil. Methodology: Treatments consisted of drench in the substrate of tubes at 8 and 15 days;  drench in the substrate of tubes at 8 and 15 days and in pot at 25 and 35 days; irrigation in pot only at 25 and 35 days after transplanting  and 2 controls (Onix® and absolute control). All pots with plants were inoculated with 5000 nematode eggs. At 45 days of transplanting, the following nematological variables were evaluated: number of galls, number of egg mass, number of eggs per gram and reproduction factor, and agronomic variables fresh and dry biomass. Results: Additions in the tube and pot and in the pot only were efficient for the reduction in the reproduction of M. javanica and for the improvement of lettuce plant growth. Conclusion: B. subtilis-34 remains viable until 9 months in formulation stored under the refrigerator and up to 7 months under room conditions.