Synergistic Effect of Foliar Spray of Sulphate of Potash and Nano Urea on Yield and Quality of Banana

Abstract

Foliar application of nutrients has emerged as a promising strategy to overcome these limitations, providing rapid and targeted delivery of essential elements directly to the plant. Nano-fertilizers, with their reduced particle size and high surface area, further enhance penetration and nutrient use efficiency, offering an innovative approach to improve plant growth and productivity. A field experiment was conducted over two consecutive cropping seasons (2022–23 and 2023–24) to assess the effects of foliar application of sulphate of potash (SOP) and nano urea on yield and yield-related traits of banana cultivated using tissue culture and sucker planting materials. Ten treatments comprising different concentrations of SOP and nano urea, applied individually and in combination, were evaluated under replicated field conditions. Foliar nutrient application significantly influenced all yield and fruit attributes across both seasons, with tissue culture plants consistently outperforming sucker plants. Among the treatments, the combined application of 1.5% SOP + 0.3% nano urea (T8) was the most effective in both years. This treatment produced the highest bunch weight in tissue culture plants (23.30 and 19.53 kg) and sucker plants (20.63 and 19.58 kg), along with the maximum bunch length (98.33 and 94.00 cm) in tissue culture and (95.00 and 90.67 cm) in sucker plants. T8 also recorded the highest hand weight (2.31 and 2.08 kg) in tissue culture and also (1.70 and 1.67 kg) in sucker plants, finger weight (168.00 and 164.00 g) in tissue culture,  (121.33 and 118.67 g) in sucker plants, finger length (23.00 and 19.67 cm) in tissue culture, (19.30 and 18.23 cm) in sucker plants, and number of fingers per hand (19.67 and 18.00) in tissue culture, (16.00 and 18.00) in sucker plants. The performance of T8 was followed by T9 (2% SOP + 0.4% nano urea) and T7 (1% SOP + 0.2% nano urea), which consistently produced significantly higher values than sole applications of SOP or nano urea. In contrast, the control treatment recorded the lowest values for all parameters evaluated. Overall, the results demonstrate a strong synergistic effect between potassium and nano nitrogen when applied in combination. Foliar application of 1.5% SOP + 0.3% nano urea is therefore recommended as an efficient and sustainable nutrient management strategy for enhancing yield and fruit quality of banana under the conditions of the present study.