The study of the effects of planting densitsy on morphological traits and seed quality in soybean (Glycine max L.)

In order to study the effect of different densities on the morphological traits, oil and protein percentages in three varieties of soybean (Glycine max L.) in climatic conditions of Kermanshah, an experiment in research field Mahidasht, Kermanshah, was conducted in 2002.A factorial experiment was carried out based on randomized complete blocks design with four replications. Varieties were placed in the blocks at 3 levels, including Williams, Zan, and Clark varieties and density at 3 levels, including plant were placed on 3, 5, 7cm intra rows spacing in the blocks (555000, 333000 and 238000 plant/ha, respectively). After harvesting plant height, number of sub branch, distance of the first sub branch from soil surface and inter node length and number of node in main stem, sub stem and per plant were recorded. The results showed that with increasing the planting density, plant height, distance the first sub branch from soil surface, number of node in main stem and inter-node length were increased. Also with decrease of density, number of sub-branch per plant was increased. Therefore, the highest number of node in main stem, plant height, distance the first sub branch from soil surface and inter node length belonged to D1 density. The study of cultivars showed that the Clark cultivar had highest number sub branch and number of node in sub stem and plant. Protein and oil percentages were not affected by cultivar and planting densities. GDD for each stage, was measured based on daily temperatures from planting to that time. Clark cultivar had the highest GDD for stages planting and R8 (physiological maturity).