Effects of foliar spraying with new zinc sources on rice seed enrichment, nutrition, and productivity

New Zn sources have emerged recently, which may boost the beneficial effects of leaf sprays on rice cropping. Thus, this study aimed to compare the effects of foliar sprays using Zn chelate against those with new Zn sources such as sorbitol-stabilised Zn nitrate and Zn oxide nanoparticles on rice seed enrichment and production. Treatments were arranged in a completely randomised design, comprising of three Zn sources and four Zn concentrations with four replicates. Rice plants were sprayed three times: at the beginning of tillering, maximum tillering, and booting stage. Experimental unity consisted of 7-dm(3) pots filled with 5-dm(3) medium textured sand. Each pot had 10 plants, of which 6 randomly harvested at the flowering stage and the remaining at the maturity stage. Plant dry matter, content and accumulation of Zn in the shoot, seed Zn content, and seed production at the grain-filling stage were also estimated. Seed production and Zn accumulation showed a quadratic behaviour with the use of novel sources. Overall the new Zn sources were more effective than the traditional EDTA chelated Zn in terms of rice seed production and quality, especially the sorbitol-stabilised Zn nitrate.