Growth, grain yield, and water productivity of different rice varieties in response to irrigation management techniques

The higher water consumption in the flooding irrigation system has challenged rice cultivation. Applying irrigation management techniques that help to save water and increase water productivity is necessary to deal with water shortage. We evaluated the growth, yield, water consumption, and water productivity responses in rice genotypes to irrigation management techniques. The experiment was arranged in a split-plot design with three replications at the Rice Research Institute of Iran, Mazandaran. The treatments were four rice varieties (Toloo, Tarom, Tisa, and Shiroudi) as main plots and six irrigation methods (continuous flooding irrigation (CFI) from transplanting to 20 days after 50% flowering (I1), CFI from transplanting to 15 days after 50% flowering (I2), CFI from transplanting to 10 days after 50% flowering (I3), CFI from transplanting to 5 days after 50% flowering (I4), CFI from transplanting to flowering stage (I5), and alternate wetting and drying (AWD) irrigation from transplanting to 20 days after 50% flowering (I6)) as sub-plots. The results showed that the Toloo genotype had the highest grain yield, lowest water consumption, and greatest water productivity compared with other studied genotypes. The I6 treatment with a slight reduction in yield (6% yield loss) was able to increase water-saving by 17.3%. HIGHLIGHTS Using rice genotypes with a short growing period can reduce water consumption and increase water productivity.; Continuous flooding irrigation throughout the growing season caused a significant increase in water consumption and a decrease in water productivity.; Alternate wetting and drying irrigation could be used as a water-saving technique for rice cultivation, especially under water shortage conditions.