Residual effect of clethodim applied in corn pre-seeding

Abstract

Brazil is one of the few countries where it is possible to produce more than one crop in the same agricultural year, and the soybean-corn succession is practiced by most of the producers. This cultural system provided the selection of weeds resistant to herbicides, mainly by the use of herbicides with the same mechanism of action in successive crops. In this scenario, new management strategies should be adopted, such as herbicide applications in corn pre-sowing. The objective of this search was to evaluate the influence of periods of application of clethodim on pre-sowing, on emergence and initial development of maize hybrids. For this, the residual effect of clethodim on hybrid 2B810 Power Core, Status Viptera 3, Dekalb 340 VT PRO2 with application of clethodim 196.80 g L-1 a.i. at 15, 10, 5, 3 and 1 day before sowing (DBS) of corn and a control without application. The variables analyzed were: emergence, plant height, falker chlorophyll index, stalk diameter, fresh and dry matter accumulation. The application of clethodim 1 day before sowing adversely affected the emergence and initial development of evaluated corn hybrids. The hybrids presented differential susceptibility to the residual of clethodim for emergence variables, accumulation of fresh matter and dry matter accumulation.