Partial and total defoliation during the filling period affected grain industrial and nutraceutical quality in soybean.

Background: Little is known about soybean grain chemical composition response to defoliation. The objectives of our study were: (i) to quantify the impact of different levels and timing of defoliation during the filling period on soybean grain yield and grain chemical content and composition, including protein, oil, fatty acids, and isoflavones; and (ii) to establish associations between them and the level and timing of defoliation.

Results: Yield and grain chemical components were reduced by defoliation treatments, these effects being more pronounced as defoliation increased.