Evaluation of water stress effect on plant yield and some traits in various cultivars of soybean

Nowadays crisis of water is one of the most important challenges in the world and Iran. Developing cultivars tolerant to drought stress should be one of the research priorities in agriculture sector. To evaluate the effect of drought stress on morphological traits and seed yield of soybean cultivars, a pot experiment was carried out as a factorial in a Randomized Complete Block Design with three replications in Gorgan in 2014. The cultivars consisted of Williams, Sahar, Gorgan3 and Katul and the treatments were the check (full irrigation), the stop of irrigation at vegetative growth stage, flowering, podding and seed filling. Planting was summer sown. Plant height and the other traits were recorded at physiological maturity and the seed yield of each plant was determined after harvesting. The results showed that the drought stress decreased seed yield, number of nodes, plant height, and the weight and length of root. The highest and lowest plant height and number of nodes belonged to G3 and Williams. Sahar and Williams produced the highest and lowest number of pods, respectively. Katul and Williams produced the highest (11.5333 g plant-1) and lowest (8.7333 g plant-1) plant seed yield, respectively. Based on the results of traits mean and seed yield, as a whole Katul and Sahar had higher tolerance to drought stress compared to two other cultivars.