Determination of the effects of cadmium applications on yield and yield parameters in soybean varieties

In this study, under controlled conditions, the effects of four different cadmium (Cd) doses (0, 2.5, 5, and 7.5 mg/kg) on yield and yield parameters were investigated in three soybean cultivars (Atlas 3616, Arısoy, and Superb. The experiment was designed according to split plot design with 3 replications. In the experiment, significant effects of cadmium on plant height, branch number, first pod length, pod number, seed number, 1000-seed weight and yield were determined depending on the variety and dose. Cd applications caused decreases in plant height between 10.2% (Superb) and 37% (Arısoy) according to varieties. Branch number decreased in all varieties as Cd dose increased; Superb was the most affected with a decrease of 40.0%, while Arısoy was relatively tolerant with 7.1%. In the first pod height parameter, Arısoy variety showed an adaptive response by increasing by 7.5% at 7.5 Cd dose, whereas stress symptoms were detected with a decrease of 25.2% in Atlas 3616. Although pod number generally tended to decrease with increasing Cd, Atlas 3616 (15.6% decrease) was found to be relatively resistant, while Superb (22.7% decrease) was found to be the most sensitive variety. At a dose of 5 mg/kg Cd, a hormesis effect on seed yield was observed in Atlas 3616 and Arısoy (with increases of 14.6% and 12.5%, respectively), whereas at a dose of 7.5 mg/kg Cd, a substantial reduction of 42.9% was recorded in the cultivar Superb. The highest loss in 1000-seed weight was recorded in Arısoy variety (24.6%), and the lowest loss was recorded in Superb variety (12.8%). In terms of yield, Atlas 3616 reached the highest value in the control group with 491.8 kg/da, but was found to be relatively resistant with a 24.3% decrease at 7.5 mg/kg Cd. Superb stood out as the most sensitive variety with a 43.8% yield loss at 7.5 mg/kg Cd. The study recommends using tolerant varieties in areas with Cd risk in agricultural production, avoiding planting in areas where soil Cd levels are above 2.5 mg/kg Cd, and tightening Cd limits in industrial wastes. Keywords: Soybean, Cadmium, 1000 Seed Weight, Yield and Yield Components