Title: Evaluation of yield and agronomical traits of selected drought tolerance genotypes using alternate wetting drying (AWD) irrigation method
Author: Morteza Nasiri
Abstract: One of the approaches to cope with water deficit and increase water productivity in paddy fields is to introduce drought cultivars that are either drought-tolerant or adapted to new irrigating methods. To achieve this objective, a field experiment was conducted during the two years of 2016 and 2017 at Rice Research Institute, Deputy of Mazandaran (Amol) with ten selected drought-tolerant genotypes. The experiment was conducted as a split-plot with three replications where irrigation method in three levels (waterlogging, wet and dry alternate method up to 10 and 20 cm below the soil surface) was the main factor, and genotypes were laid as subplots The results showed that Neda, Shiroodi and line 8611 had the highest water productivities (0.87, 0.87 and 0.84, respectively). Comparison of AWD10 and AWD20 irrigation methods with conventional methods showed that water use reduced by 20% and 17%, respectively. This water reduction resulted in 1.4% and 0.2% of yield loss and 15% and 13% of the increase in water use efficiency, respectively, compared to conventional submerged irrigation. Based on the results, milling efficiency in flood irrigation (68.7%) was lower than in the two other methods of alternative wetting and drying irrigation of 10 and 20 (69.6 and 69.8%, respectively). Based on TOL, MPI, GMP, STI, HARM, and YI drought tolerance indices, Neda, Shiroodi, and 8611 genotypes were more tolerant to drought. Therefore, Neda, Shiroodi, and 8611 genotypes which showed a good response to AWD alternative irrigation are recommended as suitable genotypes for increasing water productivity in paddy fields.
Keywords: Alternative Irrigation, Rice, Water Productivity, Drought Tolerance Indices