Response of nano dap on growth, yield and economics of cowpea (Vigna unguiculata L.)

field experiment entitled “Response of nano dap on growth, yield and economics of cowpea (Vigna unguiculata L.)” was carried out on medium black calcareous soil during the summer season of 2024 at Cotton Research Station, Junagadh Agricultural University, Junagadh located in the South Saurashtra Agro-climatic Zone of Gujarat. The experiment was laid out in a randomized block design with three replications. The experiment comprised 10 treatments in combination of soil application, seed treatment and foliar application with conventional fertilizer and nano DAP. Among these treatments, the application of 100% RDF recorded significantly higher values of growth parameters viz., number of root nodules per plant (25.19), dry weight of root nodules per plant (376.42 mg) at 40 DAS. While application of 75% RDF + foliar spray of nano DAP at 4 ml/lit at 30 DAS and 40 DAS recorded significantly higher values for plant height (52.50 cm) at 60 DAS, dry matter accumulation per plant (27.43 g) and number of branches per plant (7.33) at harvest. Application of treatment 75% RDF + foliar spray of nano DAP at 4 ml/lit at 30 DAS and 40 DAS significantly promoted yield attributes and yield viz., number pods per plant (38.60), number of seeds per pod (12.95), length of pod (15.93 cm), seed yield (1341 kg/ha), stover yield (2660 kg/ha) and biological yield (4001 kg/ha). Economic analysis showed that the maximum net return (₹ 65030 /ha) and BCR (2.59) were obtained with the application of 75% RDF + foliar spray of nano DAP at 4 ml/lit at 30 DAS and 40 DAS over control which was closely followed treatment 75% RDF + foliar spray of nano DAP at 2 ml/lit at 30 DAS and 40 DAS) and 100% RDF.