Best Time to Apply Zinc Sulphate: A Rabi and Kharif Timing Guide
For kharif crops like rice, cotton, sugarcane, and maize, zinc sulphate is best worked into the soil during land preparation, before sowing or transplanting — this gives roots time to establish zinc uptake before the vegetative growth phase, when demand for the nutrient is highest.
For rabi crops like wheat, a basal application at or just before sowing serves the same purpose, with tillering being the critical window where a zinc shortfall does the most damage to eventual yield.
Waiting until visible deficiency symptoms appear — bronzing in rice, interveinal yellowing in wheat and cotton — means the crop has already lost some growth potential; at that point, a foliar spray of dissolved zinc sulphate or liquid zinc (Scotch, 10% Zn) is the fastest way to limit further damage while a soil-applied program is planned for the following season.
Fields with a documented history of zinc deficiency, such as rice paddies affected by Hudda disease, benefit from building a zinc application into every season's routine at land preparation, rather than treating it as a reactive fix only after symptoms return.