Abstract
The impact of plant defoliation on the yield of short-season soybean cultivars was evaluated in five trials carried out in two crop seasons (2008/2009 and 2009/2010) in three states in Brazil (Rio Grande do Sul, Goiás and Mato Grosso). In 2008/2009, defoliation was performed by removing one, two or three leaflets (33.3%, 66.6% and 100% defoliation, respectively) from all leaves at different plant developmental stages (V5, V8, R2, from V5 to R2, and from V5 to harvest). In 2009/2010, the defoliation levels studied were 16.7% (half leaflet) and 33.3% (one leaflet), performed weekly during the vegetative or reproductive period, and during the entire cycle in three trials in Goiás. All tested cultivars tolerated defoliation levels equal and sometimes even higher than current Economic Thresholds (ETs) (30% vegetative stage defoliation threshold and 15% reproductive stage defoliation threshold) without significant yield loss. This indicates that even for the new cultivars belonging to shorter maturity groups or of indeterminate growth habit, soybean plants showed high defoliation tolerance. Thus, we conclude that the currently recommended ET for leaf-lamina consumers in the soybean crop is still valid and should be used by growers, even for the newer cultivars belonging to the lower maturity groups with indeterminate growth habit.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
