Effect of gibberellic acid on germination and seedling growth of Soybean (Glycine max L. Merrill)

Abstract

The germination percentage of Soybeans is susceptible and affected by many external and internal factors. Screening of three varieties of soybeans (Shimaa, Industrial2, and M103) during laboratory germination and field emergence was conducted to identify varieties with superior performance under four concentrations of gibberellic acid (0, 75, 150, 225 ppm). Experiments were conducted in Field Crops Dept./College of Agriculture/Tikrit University. Results showed significant differences between gibberellic acid concentrations, varieties, and interactions for all studied traits. Seeds treated with a concentration of (150 ppm) were superior in laboratory germination and field emergence percentages, averaging 92.58% and 59.08%, respectively. Varieties of Shimaa and M103 were superior in giving the highest germination percentage in the laboratory, 87.5% and 87.94%, respectively. The Shimaa variety outperformed, giving the highest field emergence percentage, 58.00%. Interaction of Shaima x150 ppm (GA3) showed the highest laboratory germination percentage and highest field emergence percentage, 96.75% and 63.25%, respectively. These Results indicate that the use of gibberellic acid significantly increased the germination rate of soybean seeds and field emergence rate due to the role of this hormone in stimulating the synthesis of enzymes necessary for germination and seedling vigor. Keywords: Soybean; GA3; Seed germination percentage; Field emergence percentage.