Effect of Nano Nitrogen and Chelated Zinc Foliar Spray on Growth and Yield Attributes of Guava (Psidium guajava L.)

Abstract

The present study was conducted to evaluate the effects of nano nitrogen and chelated zinc foliar application on the growth, yield, and quality attributes of guava (Psidium guajava L.) during the 2024–2025 season at Career Point University, Kota. The experiment was laid out in a factorial randomized block design (FRBD) with 16 treatment combinations comprising four levels of nano nitrogen (0, 2.0, 4.0, and 6.0 ml/lit) and four levels of chelated zinc (0, 0.2%, 0.4%, and 0.6%). Results revealed that foliar application of nano nitrogen at 6.0 ml/lit (N3) and chelated zinc at 0.4% (Z2) significantly enhanced plant height, plant spread, number of flowers per shoot, fruit set percentage, and fruit bearing percentage, while significantly reducing fruit drop. The highest performance across most growth and yield parameters was recorded under the combined treatment N3 × Z2. This study concludes that the integrated foliar application of nano nitrogen and chelated zinc is a promising strategy for improving guava productivity under field conditions.