Effect of varying doses of nitrogen and phosphorus on growth and grain yield of black wheat (Triticum aestivum L.) in North-Eastern Haryana

Black wheat has considerable nutritional and health benefits, but its cultivation is still limited due to inadequate information on suitable nutrient management practices. Identifying suitable nitrogen and phosphorus levels is therefore important for improving the growth, grain yield and overall performance of black wheat under the conditions of Northeastern Haryana. Therefore, A field experiment was conducted during the Rabi seasons of 2024–25 and 2025–26 at the Research Farm of Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana, India, to evaluate the effects of nitrogen and phosphorus on the growth, yield, and economics of black wheat (Triticum aestivum L.) under the agro-climatic conditions of North-Eastern Haryana. The experiment was laid out in a randomised block design with three replications and ten treatments comprising three nitrogen levels (120, 150, and 180 kg N/ha) and three phosphorus levels (45, 60, and 75 kg P₂O₅/ha), along with a control. Two-year results revealed that increasing nitrogen and phosphorus levels significantly improved growth, yield attributes, and grain and straw yields. The highest spike density (59.68 and 61.38/m), spike length (10.41 and 10.92 cm), grains/spike (38.56 and 39.33), test weight (36.46 and 36.83 g), grain yield (4041 and 4140 kg/ha), and straw yield (5602 and 5735 kg/ha) were recorded with T₁₀ (180 kg N + 75 kg P₂O₅/ha). However, T₁₀ remained statistically at par with preceding nutrient treatments, indicating a yield plateau at higher fertiliser levels. Harvest index was not significantly affected. T₁₀ produced the highest gross returns (₹230,060 and ₹235,675/ha) and net returns (₹156,245 and ₹161,860/ha). However, the B:C ratio (3.13 and 3.24) was comparable from T₆ to T₁₀. Considering economic efficiency and reduced fertiliser use, T6 (150 kg N + 60 kg P₂O₅/ha) was identified as the optimum treatment for profitable and sustainable black wheat production in North-Eastern Haryana.