‘BMX Ativa’ soybean responses after application of biofertilizer associated or not with glyphosate

Even with the development of glyphosate-resistant soybean, there are cases in which harmful effects of intoxication occur, especially when the herbicide is applied in mixture with other products. The objective of this work was to verify the efficiency of biofertilizer as a glyphosate stress reducer in the soybean “BMX Ativa”. The experiment was installed in a randomized block design, in a 3 × 5 + 1 factorial scheme, with four replications. In factor A, soybean development stages (V4, V8 and V4 + V8) were allocated, and in factor B the application of 0.1 L ha-1 of biofertilizer, 1,080 and 2,160 g ha-1 of a.e. of glyphosate, applied in isolated mode and/or mix in tank, plus one control without application as an additional treatment. The evaluated variables were phytointoxication, number of grains per plant, number of pods per plant, thousand grains mass and soybean grain yield. The application of double the dose of glyphosate (2,160 g ha-1) alone or in mixture with the biofertilizer in stages V4, V8 and V4 + V8 caused visual injuries to soybean ‘BMX Ativa’ until 28 days after application, but without affect the productive characteristics of the crop. The biofertilizer did not affect soybean plants and neither mitigate the negative effect of the highest dose of glyphosate.