Investigation on the effective indices on yield in delayed sowing of different soybean cultivars in Zanjan region, Iran

Soybean, Glycine max L. is one of the valuable oil and proteinous grain plants and it’s sowing area is expanding annually because of need to both oil and protein sources in our country. Because of some difficulties in on-time cultivation of soybean, an experiment was carried out to investigate the adaptation possibility of the plant in delayed sowing. A randomized complete block design (RCBD) was conducted at research field of Zanjan university with three replicates. In this study, five soybean cultivars including Zan, Clark, Certificated Sahar, Habit and SRF were examined. Indices of chlorophyll content, canopy temperature and bush height were evaluated at flowering stage (R). Grain and biological yield, oil and protein yield, oil and protein percent of grains, and index of harvest were also studied at physiological maturation stage (R8). Results showed significant differences of cultivars in most characteristics. The highest grain, oil and protein yields, harvest index and leaf chlorophyll were related to Habit cultivar. There were no significant differences among cultivars in canopy temperature, and oil and protein percentage of grain. hundred seed weight was the most important trait to distinct cultivars. The results of correlation studies between traits revealed that the chlorophyll content index, harvest index, and hundred seed weight were the most effective factors on grain oil and protein yield and might be regarded in cultivar selection. Based on the results, Habit cultivar showed more suitale growth period lenth and better adaptation to photoperiod and temperature of the studied region and so could be a suitable option to supplemental researches in delayed sowing and double planting studies.