International Journal of Plant & Soil Science

A field experiment trial on blackgram was conducted during Zaid, 2021 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (U.P), India. The soil of the experimental plot was sandy loam in texture, nearly neutral in soil reaction (pH 7.3), organic carbon (0.73%), available nitrogen (274.46 kg/ha), available phosphorus (31.10 kg/ha), and available potassium (328 kg/ha). The foliar spray was applied thrice at different concentrations (5.0, 7.5, 10, and 15.0% v/v) of seaweed extract of Gracilaria edulis (G. Sap) with different levels of phosphorus (30 and 40 kg/ha) and control plot with water spray. The experiment was laid out in Randomized Block Design with nine treatments each replicated thrice. The results showed that viz: plant height (42.84 cm), number of branches per plant (7.07), number of nodules per plant (14.11), root dry weight (0.41 g/plant) were recorded significantly higher with 15% G. Sap + Phosphorus 40 kg ha^-1. Whereas, plant dry weight (17.55 g/plant) was recorded significantly higher with 10% G. Sap + Phosphorus 40 kg ha^-1. Also, the highest gross returns (62,716.50 INR/ha), net returns (26,259.00 INR/ha), and benefit-cost ratio (1.72) were obtained with the application of 15% G. Sap + Phosphorus 40 kg ha^-1 when compared to other treatments. Thus, foliar application of seaweed extract could be a promising option for yield enhancement in blackgram.