The study tested different levels of phosphorus and molybdenum on the growth and economics of blackgram plants. They found that using 40 kg/ha of phosphorus along with molybdenum foliar spray at 25 days after sowing resulted in the tallest plants, the most branches, the highest number of nodules, the heaviest dry weight, the fastest crop growth rate, and the highest grain yield. This treatment also led to the highest gross returns, net returns, and benefit-cost ratio.