Investigation on changes of growth indices of rice (Oryza sativa L.) in different growth stages under irrigation regimes in Khuzestan, Iran

This study aimed to investigate the effect of irrigation regimes on grain yield and physiological indices of aerobic rice genotypes inKhuzestan province for two years (2014 and 2015). Four irrigation regimes (1, 3, 5 and 7 days) in main plots and 12 rice genotypes in sub-plots with three replications were considered. The combined analysis results showed that there were significant differences between genotypes, irrigation regimes and their interaction at all growth stages at 1%. SWR also increased with growth, but 100 days after planting due to the effective role of stem particularly in terms of reducing the amount of water, a decline was seen in this trait. By decreasing the irrigation regime due to less canopy shading, the NAR slowed down. The highest LWR were observed under 5- and 7-day in irrigation regimes, but SLW decreased in these irrigation regimes. The mechanism of escape from stressful conditions reduced the growth period by decreasing the irrigation regime. Finally, it is recommended that this experiment be carried out in irrigation regimes and other genotypes.