Silicon and Zinc Improves Grain Yield and Nutrient Status in Rice When Supplied During the Different Growth Stages

Silicon (Si) and zinc (Zn) has been recognized as beneficial elements to improve rice (Oryza sativa L.) grain yield. The present study was aimed at investigating the effects of silicon and zinc foliar application at different growth stages on yield components, grain yield, and concentration of silicon and zinc in rice grain. The experiment design was a factorial two-factor randomized complete block design (RCBD) with three replications. Treatments included the fertilizers foliar application at 3 levels (Potassium silicate, Silicon nanoparticles, Zinc Oxide nanoparticles) and rice growth stages at 5 levels (T1: early tillering + middle tillering + late tillering + full heading stage; T2: middle tillering + late tillering + full heading stage; T3: late tillering + full heading stage; T4: late tillering; T5: full heading stage). The results indicated that the application of Si and Zn nanoparticles was superior to potassium silicate in terms of improving the yield components, yield and nutrients concentration in rice grain. Application of Si and Zn nanoparticles increased the grain yield by 7.4 and 4.5%, respectively, above the potassium silicate. Foliar application of nutrients in both T1 and T2 stages led to improved grain yield (7716 and 7700 kg.ha-1 , respectively). The highest Si concentration in grain was obtained by foliar application of nano-Si at the T1 and T2 stages (3.97 and 3.83%, respectively), while the maximum Zn concentration in grain was observed with the nano-Zn application at the T2 stage (21.67 mg.kg-1 ). In general, we suggest applying Si and Zn nanoparticles at the middle tillering + late tillering + full heading stages to improve the yield and rice grain fortifying.