Optimization of drone-based foliar application of VSI liquid fertilizers for enhanced growth and yield of sugarcane

Sugarcane (Saccharum officinarum L.) productivity depends on efficient nutrient management throughout its long growth period. Soil-applied fertilizers alone are often insufficient due to nutrient losses, making foliar nutrition an effective supplement. A field experiment was conducted during the suru season of 2023-24 at Lonarwadi Farm to evaluate manual and drone-based foliar application of VSI liquid fertilizers and to optimize their dose and schedule in sugarcane (var. Co 86032). The experiment was laid out in a randomized block design with eight treatments and three replications. Foliar sprays of Vasanturja, VSI Plant Health, macronutrients, and micronutrients were applied at 60, 75, and 90 days after planting through manual and drone spraying at different spray volumes. Results showed that drone spraying at 1.0 m height using 45 L ha⁻¹ produced cane yield (143.2 t ha⁻¹) and CCS yield (20.79 t ha⁻¹) comparable to conventional manual spraying. Growth parameters were significantly improved, while juice quality remained unaffected. Drone-based foliar nutrition also recorded a high benefit-cost ratio (2.62), indicating its economic feasibility. Optimized drone-based foliar fertilization proved to be an efficient and sustainable approach for sugarcane production.