Impacto de herbicidas associados ou não a fertilizantes no desenvolvimento de plantas de soja (Glycine max l) resistentes ao Glyphosate

Abstract

The major productivity at soybean crops (Glycine max L.) is associated with the capacity to avoid the competition for water, light and nutrientes this is and weeds. Avoiding this competition, the use of glyphosate and clethodim herbicides appear as an alternative to common use. In contrast, these affect invasive plants in a systemic way, and it can damage the crop physiology, reflecting negatively on their productivity. One good solution to reduce these efects is align these herbicides with products containing micronutrients and amino acids. The main of this research is to analyze the impact of herbicides: glyphosate and clethodim isolated, in mixture, and associated with fertilizers at soybean development. For this purpose, it was made a Fully Randomized Design (FRD) contained 6 treatments and 6 repetitions. The treatments were made with the aid of CO2 pressurized sprayer calibrated for an application rate of 120L.ha-1 according to comercial dosage. The parameters evaluated were: plants height, branches number, knots number, average lenght between knots, pods number, number of seeds into pods, weight of 1.000 seeds, and productivity. In exception of average lenght between knots that did not present statistics difference among treatments, in all parameters analysed the T7 treatment (Glyphosate+Clethodim+F1+F2) presented good results. These results suggest T7 as a good option to soybean cultivation, because it increases the productivity while it reduces the fitotoxic effects of herbicides. Key words: