Effect of Foliar Application of Phytoprotectants on Yield of Rice (Oryza sativa Cv. Shiroudi) under Drought Stress

Drought is one of the most important factors limiting crop yield and foliar application of phytoprotectants is an important management strategy for increasing crop resistance to drought stress. This research was conducted at Rice Research Station of Tonekabon, Iran, in 2018 by using a split-plot based on a Randomized Complete Block Design (RCBD) with three replicates. Main plots were irrigation regimes [common irrigation (control), and irrigation withold from tillering stage (45 days after transplanting)] and subplots were foliar application of phytoprotectants (control, selenium, silicon, ascorbic acid, salicylic acid). The results showed that irrigation withold from tillering stage caused a 29.3% reduction in grain yield in the absence of foliar application. Drought stress decreased plant height, tiller number and 1000-grain weight by 15.5, 14.95 and 3.34%, respectively. Drought stress increased proline content by 115%. Also, in the irrigation withold from tillering stage, foliar application with selenium, silicon, ascorbic acid, and salicylic acid led to increase in floret fertility percentage and 1000-grain weight, thereby increasing the grain yield up to 32.6, 31.9, 35.3 and 33.3%, respectively, compared to no foliar application (control). In general, the results of this study showed that foliar application of phytoprotectants can reduce the adverse effects of drought stress and improve the grain yield of rice under drought stress conditions.