Response of broccoli (Brassica oleracea L. var. italica) to foliar application of nano di-ammonium phosphate (DAP)

Abstract

Broccoli (Brassica oleracea L. var. italica) is a nutrient rich cruciferous vegetable valued for its vitamins, antioxidants and minerals. Using nano di-ammonium phosphate (DAP) in vegetable production has become important due to improve nutrient use efficiency, control nutrient release and reduce nutrient losses and leads to increased crop productivity and sustainability. A field experiment was conducted during the rabi season of 2024 to evaluate the effects of two nano DAP formulations (8 : 16 : 0 and 2 : 5 : 0) as foliar sprays at different concentrations in combination with  75 % of recommended dose of nitrogen and phosphorus (RDNP) on broccoli hybrid NS 50. The trial used randomised block design (RBD) with  10 treatments and 3 replications. The results revealed that the treatment with 75 % RDNP + nano DAP (2 : 5 : 0) at 5 mL L-1 recorded the highest root girth (23.14 cm), north-south plant spread (67.13 cm), main head weight (440.17 g), head diameter (15.23 cm), marketable yield (12681.40 kg ha-1), number of side sprouts (6.00) and ascorbic acid content (95.08 mg/100 g), achieving a 23.76 % higher yield than 100 % recommended dose of fertiliser (RDF). The above-mentioned treatment also ensured the earliest head initiation (67 days after sowing (DAS)), 50 % head initiation (68 DAS) and peak harvest (84 DAS) along with the highest soil organic carbon (SOC) (10.31 g kg-1), net income (₹936781) and benefit-cost ratio (2.60). This study suggests that 75 % RDNP + nano DAP (2 : 5 : 0) at 5 mL L-1 is highly effective for improving growth, earliness, yield, quality, economic returns and soil fertility of broccoli, while lowering the requirement of conventional fertilisers up to 25 %.