Increase of soybean cultivation under no-tillage has leveraged the use of glyphosate for soil cover crop desiccation. The objective of this work was to evaluate the effect of conventional tillage and no-tillage with different times of millet desiccation on the initial development of two soybean cultivars. The experiment was carried out in field conditions, in very clayed Red Latosol (Rhodic Acrustox). A randomized complete block design was used, in a factorial 2 x 3, with four replicates, consisting of two cultivars, BRS 240 (conventional) and CD 214 RR (GM); and three management systems: conventional tillage (CONV); no-tillage with desiccation immediately before sowing (AP) and desiccation 21 days prior to soybean sowing (D21). The growing millet was desiccated with glyphosate at a dose of 960 g i.a. ha-1. The conventional cultivar BRS 240 showed greater mass of green plants than the cultivar CD 214 RR. No-tillage (AP) negatively influenced BRS 240. In both cultivars, the management system (AP) showed the lowest values of field emergence and final stand of plants. No tillage (AP and D21) provided better root development and greater number of nodules, not influencing the nitrogen and manganese levels of the soybean plants.
glyphosate; root length; nodulation and mineral nutrition
