Herbicides selection for controlling soybean volunteer plants resistant to glyphosate

Abstract

This study aimed to evaluate the effectiveness of herbicides in controlling soybean volunteer plants resistant to glyphosate. The experiment was conducted in field conditions by using randomized complete block design in factorial scheme 6x9, with four replications, with the first factor represented by six soybean genotypes resistant to glyphosate herbicide (BRS Favorita RR® , BRS Valiosa RR® , CD 219 RR® , M-SOY 7908 RR® , P98Y11® and P98R31® ) and the  second factor represented by herbicides sprayed isolated or in mixture (2,4-D, 2,4-D + glyphosate, metsulfuron-methyl, metsulfuron-methyl + glyphosate, [MSMA + diuron], [MSMA + diuron] + glyphosate, [paraquat + diuron], [paraquat + diuron] + glyphosate, and a check without herbicide). MSMA+diuron and [MSMA+diuron] + glyphosate treatments showed effective control only for CD 219 RR® . Metsulfuron-methyl+glyphosate showed efficacy in controlling M-SOY 7908 RR® , P98Y11® , P98R31® , BRS Favorita RR® and CD 219 RR® ; as soon as BRS Valiosa RR® was the most tolerant to this treatment. Glyphosate addition did not cause any antagonist effect in effectiveness of the herbicides, but increased the action of metsulfuron-methyl. The herbicides [Paraquat + diuron] and 2,4-D were effective in controlling RR soybean crop. There were differences in sensitivity of genotypes to metsulfuron-methyl, metsulfuron-methyl + glyphosate, [MSMA + diuron] and [MSMA + diuron] + glyphosate herbicides.