Effect of Irrigation Management on Yield and Yield Components of Different Rice Genotypes (Case Study: Amol)

At this day and age continuous flood irrigation during the crop growth period in the paddy fields of northern Iran has caused high water consumption (WC). Due to the lack of water resources in Iran, proper irrigation management is necessary to reduce WC in different rice cultivars. Therefore, the present study was conducted to investigate the effect of irrigation management on yield and yield components of four rice genotypes.

The experiment was conducted as split plot in a randomized complete block design with three iterations at the research farm of the Iranian Rice Research Institute, Mazandaran Deputy (Amol). In this experiment, rice genotypes at four levels (G1: Toloo, G2: Tarom, G3: Tisa and G4: Shiroudi) as main factor and irrigation at six levels (I1: continuous flooding (CF) from transplanting to 20 days after 50% flowering and then cutting irrigation, I2: CF from transplanting to 15 days after 50% flowering and then cutting irrigation, I3: CF from transplanting to 10 days after 50% flowering and then cutting irrigation, I4: CF from transplanting to 5 days after 50% flowering and then cutting irrigation, I5: CF from transplanting to flowering stage and then cutting irrigation and I6: Intermittent irrigation from transplanting to 10 days before harvest and then cutting irrigation) were considered as sub-factors. At physiological maturity, the yield and yield components such as plant height, panicle length, total number of tillers per hill, number of filled grains per panicle and 1000-grain weight were measured.

The results showed that the highest and lowest grain yield were 6765 and 4255 kg.ha-1 from Toloo and Tarom cultivars, respectively. Application of I1 resulted in maximum grain yield (6291.8 kg.ha-1), while with the application of I5, yield decreased by 17.4%. Application of I6 while producing optimal grain yield (5911 kg.ha-1), can have a good ability to reduce WC in paddy fields, so it was selected as the best irrigation management option in case of water shortage for irrigation.

According to the results, intermittent irrigation from transplanting to 10 days before harvest and then cutting irrigation in rice plant in the study area will have acceptable yield in water deficit conditions and to achieve maximum yield, Toloo cultivar as a suitable genotype is suggested.