Agronomic performance of RR® soybean cultivars using different pre-sowing desiccation periods and distinct post-emergence herbicides

Abstract

The current study aims to measure the effect of pre-sowing desiccation period and verify the influence of post-emergence herbicide on soybean agronomic traits and grain yield. The experiments were carried out according to a randomized complete block design with three replications during two crop seasons (2012/13 and 2013/14), using split plot design. Five soybean cultivars were used (BRS Favorita RR® , TMG 1179 RR® , TMG 1176 RR® , Anta 82 RR® , NS 7100 RR® ). Two desiccation periods were adopted 7 days before sowing and just before sowing. Two types of weed management were tested in postemergence - using glyphosate (Roundup Ready® ) and a soybean selective herbicide (Robust® ). During the 2013/2014 crop season, manual weeding was also used. The evaluated traits were plant height, first pod insertion, number of pods per plant and number of seeds per pod, 1,000-grain weight and grain yield. Considering the distinct post-emergence herbicides, there was no significant difference between glyphosate and Robust® . Nevertheless, the desiccation period showed significant differences in plant height, number of pods per plant and grain yield. The soybean grain yield was higher when desiccation was done 7 days before sowing. Therefore, an association between desiccation period and soybean performance was assumed.