Effects of Waterlogging During Reproductive Stage on Growth and Yield of Soybean

Abstract

Growth and yield response of four soybean [Glycine max (L.) Merrill] varieties, SJ.5, CM.60, #75 and AGS292 under 4 durations of waterlogging (3, 5, 7 and 9 days) at reproductive stage (R1-R2) was studied in dry season during November 2008 to February 2009 at Mae Hea Agriculture Research and Training Center, Faculty of Agriculture, Chiang Mai University. Increase the durations of waterlogging from 3 to 9 days during the reproductive stage (R1-R2) reduced total dry matter accumulation, 100 seed weight ,crop growth rate (CGR), pod growth rate (PGR) and partitioning coefficient of photosynthate to the pod  of all varieties. It was clear that under waterlogging conditions soybean plants partitioning  more assimilation to the leaf and to the stem than to the pod. The #75 variety (vegetable soybean type) produced the highest seed yield (15.61g/plant) and have the highest partitioning coefficient of photosynthate to the pod (49.61%) under the long waterlogging duration (9 days). Vegetable soybean type varieties (#75 and AGS292) had higher yield and tolerated  greater  waterlogging stress than the grain type varieties (SJ.5 and CM.60).