Effect of Drought Stress and Methanol on Amount of Protein and Grain Oil, Rate and Period of Filling on Soybean (L17)

In order to evaluate effects of and methanol application on grain yield, oil and protein contents, rate and length of grain filling process of soybean under drought stress, a factorial experiment was done at Research Field of Faculty of Agriculture and Natural Resources, Islamic Azad University-Karaj Branch, Karaj, Iran, during 2008, based on a randomized complete block design with three replications. The first factor was consisted of different levels of methanol equal to 0 (control), 7, 14, 21, 28 and 35 volumetric percentage (v/v), which were used as foliar applications at three times during growth season of soybean, with 15 days intervals. The second factor was water stress conditions in two levels, based on depletion of 40 and 70% of available soil moisture. Some traits such as grain yield, 1000 grains weight, grain protein and oil contents and time of filling process were measured. Results show that there was a significant difference in grain yield, 1000 grains weight, seed yield and protein and oil content among different irrigation regimes in 5% probabilities level. There was a different effect (p>0.05) of applying methanol solutions on grain yield, 100 grains weight, seed yield, protein content and length of grain filling, with the highest values were obtained with applying 14% and 21% methanol solutions. The grain yield had positive correlations with oil and protein yields and 1000 grains weight, and a negative correlation the rate of grain filling. Interactions of methanol and irrigation regime on traits were not significant.