Effect of Basal and Foliar Application of Zinc Sulphate Fertilizer on Zinc Uptake, Yield and Yield Components of Rice (Hashemi Cultivar)

Zinc (Zn) next to N and P is the most important nutrient that its deficiency is considered to be a serious widespread nutritional disorder of the world’s rice paddy fields which causes yield reduction. The current field study was conducted to explain the effect of Zn application (basal and foliar) on morphological characteristics, rice yield and yield components, and more broadly, grains bio-fortification (Zn and protein content). The two factors factorial experiment was conducted in a completely randomized design with three replications in the farmer field in 2018-2019. The applied treatments were basal application of zinc sulfate at three levels (0, 10 and 20 kg.ha-1 Zn), and foliar application 0.5% zinc sulfate (ZFA) in four levels (no ZFA, ZFA at maximum tillering, ZFA at flowering and ZFA at grain filling stages). Basal Zn sulfate was applied before ploughing and thoroughly mixed with the surface plough layer. Results showed that almost all of the collected data except amylose content and gelatinization temperature were significantly affected by basal and foliar application of Zn, and their interactions (P≤0.01 or P≤0.05). The highest value of spikelet per panicle, grains per panicle, 1000 grains weight, grain yield and biomass were found at 20 kgha-1 basal Zn application and foliar application at maximum tillering and flowering stage, meanwhile the highest grain Zn content and white rice protein content were observed at 20 kgha-1 and foliar application at grain filling stage. The highest Zn content in all rice tissues were obtained at 20 kg.ha-1 basal application. The maximum Zn content in leaves and stems, roots, and panicles were found by foliar application at maximum tillering, flowering and ripening stages, respectively. It can be concluded that in order to produce higher grain and straw yield, the higher Zn treatment and earlier foliar application, whereas for quality factors, latter stage application were effective.