Evaluation of the Effects of Salinity Stress on Yield Parameters of Soybeans (Glycine max) Cultivated in Obubra Local Government Area of Cross River State, Nigeria

A pot experiment was conducted in the screen house at the Cross River University of Technology, Obubra Campus to evaluate the effect of different salt concentrations on the yield of three different varieties of soybeans (Glycine max). The experiment was laid in complete randomized design (CRD) with twenty replicates for each variety. Yield parameters which include number of pods per plant, 100 seed weight (g) and seed yield were measured, and data collected was subjected to statistical analysis using Analysis of variance (ANOVA) and means were compared using Duncan’s New Multiple Range Test (DNMRT). The results showed that salinity stress led to a significant reduction in number of pods per plant over control. At 30mM Nacl which was the highest level of saline water TGX 1987-10F had a better salt tolerance level as compared to other varieties, which might be as a result of some salt tolerance genes. 100 seed weight (g) reduced significantly under salinity stress as compared with the control, but TGX 1987-10F showed better salt tolerance level as compared with other varieties. Seed yield per plant decreased significantly with increasing salinity levels and a greater reduction was observed in TGX 1448-2E and TGX 1835-10E. It was concluded that Soybean is a sensitive plant to salinity stress, but the extent of this sensitivity varies among varieties. TGX 1987-10F showed a better tolerance level as compared with other varieties. Therefore, it is recommended that TGX 1987-10F can be cultivated in saline areas.