Evaluation of foliar spray of zinc and boron on growth, flowering and yield of tomato (Solanum lycopersicum cv. Srijana) under polytunnel in Nepal

This research was conducted in Budhanilkantha, Kathmandu from February to June 2023 to study the effects of different concentrations on growth, flowering and yield of tomato in Randomized Complete Block Design (RCBD) with five treatments: control (T0), two levels of chelated zinc (30 ppm - T1 and 60 ppm - T2), and two levels of borax (30 ppm - T3 and 60 ppm - T4), applied 15 and 35 days after transplantation (DAT). The results showed that chelated zinc at 30 ppm significantly enhanced plant height (86 cm), leaf number (52.47), branch number (8.21), fruit clusters (19.32), fruit number (22.73), fruit diameter (5.58 cm), fruit weight (59.71 g), and yield (56.56 t/ha). Borax at 30 ppm promoted early flowering (23.70 days). Higher concentrations of both micronutrients resulted in reduced growth and yield. The findings suggest that foliar application of 30 ppm chelated zinc and borax can optimize growth and yield of tomato. The study highlights the potential of these easily accessible micronutrient sources to significantly enhance tomato productivity under polytunnel cultivation.