Foliar Application of Boron Nanoparticles to Enhance Productivity, Postharvest Quality and Nutrient Use Efficiency in Summer Tomato (Solanum lycopersicum L.)

Abstract

: The productivity of summer tomato in subtropical regions is hampered by boron (B) deficiency, an element essential for reproductive development. Conventional soil or foliar applications often suffer from nutrient leaching and inadequate uptake. Nanoboron fertilizers offer a highly efficient and innovative alternative; their small particle size and high surface-to-volume ratio enhance cellular penetration. This study evaluated the efficacy of foliar-applied boron nanoparticles in improving summer tomato productivity, fruit quality, nutrient use efficiency and profitability, while determining the optimal dosage for maximizing yield. A field study was conducted using a randomized complete block design with three replications. The five treatments consisted of four concentrations of nanoboron (0, 0.2, 0.3, and 0.4 g L − 1 ) along with conventional boric acid at 1 g L − 1 . Treatments were applied as foliar sprays at 20 days after transplanting (DAT) (corresponding to flower initiation), 35 DAT (corresponding to peak flowering and initial fruit set), and 50 DAT (corresponding to late fruit set and early fruit expansion). The application of boron nanoparticles significantly outperformed conventional boric acid in terms of all the measured parameters. The highest results were observed with 0.2 g L − 1 nano B fertilizer (T 2 ), which increased the fresh fruit yield (41.2 t ha − 1 ) by 59.7% compared with that in the control treatment and 9.57% compared with that in the conventional boric acid treatment. This increase was attributed to greater individual fruit weight (53.0 g), maximum number of fruits per plant (43.7), and greatest plant height (110 cm). The same treatment (T 2 ) resulted in the highest total soluble solids (TSS) (5.53 ◦ Brix), vitamin C (34.7 mg/100 g) and β -carotene (21.8 µ /g) contents and the highest B uptake (604 g ha − 1) and B use efficiency. T 2 treatment prominently increased the cost-benefit ratio (5.94). The results suggest that 0.2 g L − 1 nanoboron is the optimum dosage for maximizing the yield, quality and profitability of summer tomatoes under experimental condition. Hence, this technique provides a precision-based farming solution to the challenges associated with soil B fixation, leading to higher yields and better fruit quality with less waste.