Effect of different doses of nitrogen on growth, yield and quality of potato (Solanum tuberosum L.) cv. kufri neelkanth

A field experiment was conducted during rabi season of 2024-25 at Research Field of the Vegetable Science Centre of Excellence of C. S. Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India. The present investigation was conducted to evaluate the effect of different nitrogen levels on growth, yield, nitrogen uptake, and economics of potato under the prevailing agro-climatic conditions. Treatments included nitrogen application rates ranging from 0 to 350 kg N/ha. The results revealed significant differences among treatments. Plant emergence improved with nitrogen application, with the highest emergence (95.93%) recorded at 100 kg N/ha, compared to 91.48% in the control. Plant height, number of shoots, and leaf production all increased progressively with nitrogen, showing sharp gains up to 150-200 kg N/ha, beyond which improvements were marginal. Maximum plant height (69.4 cm), shoot number (6.0 per plant), and leaf count (45.8) were obtained at 200-350 kg N/ha, while haulm yield (fresh: 23.4 t/ha; dry: 2.53 t/ha) plate a used beyond 200 kg N/ha. Tuber yield and its components were markedly influenced by nitrogen. The number of marketable tubers (>75 g) increased from 85.00 in the control to 234.00 at 200 kg N/ha. Total tuber yield rose from 181.20 q/ha in the control to a maximum of 378.20 q/ha at 200 kg N/ha, with a marginal decline at higher levels. Similarly, dry matter yield of tubers (6,921 kg/ha) and plants (2,344 kg/ha) peaked at 200 kg N/ha, while dry matter content showed a slight, non-significant reduction with higher nitrogen. Nitrogen uptake followed a similar trend, with maximum total uptake (140.09 kg/ha) at 200 kg N/ha. The harvest index was highest (75.01%) at 150 kg N/ha, indicating more efficient biomass partitioning at this dose. Economic analysis demonstrated that 200 kg N/ha (T₅) was the most profitable, producing the highest tuber yield (37.82 t/ha), gross income (₹3,78,200), net return (₹2,63,849), and benefit-cost ratio (2.31). Although higher nitrogen levels produced comparable yields, increased input costs reduced profitability during the experimentation.