اثر تنش خشكي بر عملكرد و اجزاي عملكرد سه رقم سويا

Effect of Drought Stress on Yield and Yield Components of Determinate Soybean {Glycine max (L) Merrill)

The effect of drought Stress on branch and main stem yield and yield components of determinate soybean [Glycin max L.) Merr], was evaluated in factorial experiment on completely randomized design with four replications at the Greenhouse of Agriculture Faculty of Shahr-e- Kord University in 2005. The experimental factors were three determinate soybean cultivars (Hutcheson, Brim and Stonewall) and three drought stress levels; control; irrigate at 50% (Si); and at 25% available water (S2). Drought stress did not decrease grain yield of the main stem but decreased it in the branches severely. The highest grain yield of main stem and its contribution to total grain yield were obtained to be 6.53gr, and 65.23%, for S2 and 6.21gr, 44.23% for Si and 5.98gr, 36.04% for control treatments respectively. The highest grain yield of the branches and their contribution to total grain yield in control, Si and S2 were obtained to be 10.61gr, 63.95%; 7.83gr, 55.76%; and 3.48gr, 34.76% respectively. Number of grains per branch was highly correlated with their grain yield , total grain yield , branch length and branch number (p<0.01).