Efficacy of potato (Solanum tuberosum) cultivars under varying levels of nitrogen and growth duration in eastern Indo-Gangetic plains Kumar Manoj*, Trehan S.P.**, Jatav M.K.***, Lal S.S.1 1Central Potato Research Station, Patna, Bihar, 801 506. *Corresponding author: (E-mail: manoj_kumar001@yahoo.com)
Present address: **Division of Crop Production, Central Potato Research Institute, Shimla-171 001. ***Central Potato Research Station, Jalandhar, Punjab, 144 003. Abstract A field study was conducted during winter seasons of 2004–05 and 2005–06 at Patna with three potato (Solanum tuberosum L.) cultivars namely ‘Kufri Giriraj’, ‘Kufri Pukhraj’ and ‘Kufri Jyoti’, four nitrogen levels (0, 80, 160 and 240 kg/ha) and two growth durations (75 and 100 days) to work out the optimum level of N, efficiency and eco-friendliness. ‘Kufri Pukhraj’ gave the highest yield (28.7 t/ha) and N uptake (105.8 kg N/ha) and was most efficient in utilizing N from soil and applied N (uptake efficiency 0.54 kg/kg N). The increase in growth durations improved the tuber yield at higher N levels (160 and 240 kg N/ha). The highest increase in agronomic and uptake efficiencies with increasing growth duration was recorded at 160 kg N/ha (42 for agronomic and 0.1 kg/kg N for uptake efficiency). Yield at economic optimum N was normally higher in longer growth durations with higher nitrogen requirement (9.7 and 7.6 t/ha at 81 and 37 kg/ha, higher N for ‘Kufri Giriraj’ and ‘Kufri Jyoti’, respectively), however, for ‘Kufri Pukhraj’ economic optimum N dose decreased by 22%. Eco-friendliness with respect to nitrogen utilization both in absolute and relative indices was maximum in ‘Kufri Pukhraj’ followed by ‘Kufri Giriraj’. Net return and benefit:cost ratio was higher when longer growth duration was given, however, when crop is to be harvested early ‘Kufri Pukhraj’ is the best option. Top Key words Biocoenosis, Economic viability, Efficiency, Potatoes, Nitrogen, Yields. Top |