Agronomic Performance of RR (R) Soybean Submitted to Glyphosate Application Associated with a Product Based on Bacillus subtilis

Despite the great benefits arising from the adoption of Roundup Ready((R)) (RR (R)) soybean, there are reports about the lack of selectivity of glyphosate for this crop. The use of growth-promoting microorganisms can help attenuate the injuries caused by herbicides. The objective of this work was to evaluate the agronomic performance of RR(R) soybean submitted to the post-emergence application of glyphosate both isolated and in association with Bacillus subtilis. The experiment was carried out in a completely randomized block design, with four replications. The treatments consisted of the post-emergence applications of glyphosate (1296 g a.i. ha(-1)), glyphosate (2592 g a.i. ha(-1)), glyphosate/glyphosate (1296/1296 g a.i. ha(-1)), glyphosate + B. subtilis BV02 (1296 + 42 g a.i. ha(-1)), glyphosate + B. subtilis BV02 (2592 + 42 g a.i. ha(-1)), and glyphosate + B. subtilis BV02/glyphosate + B. subtilis BV02 (1296 + 42/1296 + 42 g a.i. ha(-1)). The application of glyphosate (2592 g a.i. ha(-1)) and the sequential application of glyphosate provides higher levels of intoxication. The association of B. subtilis BV02 with glyphosate (2592 g a.i. ha(-1)) prevented losses in the values of relative chlorophyll a and b and the total chlorophyll index. The soybean yield was reduced when the plants were submitted to a sequential application of glyphosate.