Flooding and Temperature Effects on Soybean Germination

Abstract

During the germination phase of soybean [Glycine max (L.) Merr.] growth, uniform soybean emergence may be reduced when fields are periodically saturated with water from heavy rains and poor drainage. A laboratory study was conducted to determine the effects of timing and duration of flooding, germination temperature, and mechanical damage on the germination of soybean. There were little differences in germination percentage among the flooding duration treatments when flooding began 1 d after the start of imbibition. When seed were flooded 2 or 3 d after the start of imbibition, however, a significant drop in germination percentage occurred in seed flooded for 48 h. Flooding seed 3 d, compared with 1 d, after the start of imbibition was more detrimental, regardless of temperature. Seed injury was observed after only 1 h of flooding. Increasing the duration of flooding from 1 to 48 h at 15°C did not increase injury; however, at 25°C, more seed injury was observed as the duration of flooding increased up to 48 h. Overall, seed were more susceptible to flooding stress at 15°C than at 25°C. These results suggest that soybean seed are susceptible to flooding of 1 to 48 h during the early germination process and the response is influenced by germination stage.