Variety
The response of variety to N application is positively correlated with its maturity group, genetical potential to produce large grade tubers and more importantly, K composition of the tuber. Long duration varieties, varieties producing more number of large size tubers and varieties showing high uptake of K respond to high levels of N. The long and medium duration varieties like Kufri Badshah, Kufri Sindhuri and Kufri Jyoti are more responsive to N than the short duration varieties like Kufri Chandramukhi.
The economic response of potato in alluvial soils of northwestern and central Indo- Gangetic plains in the country has been noticed up to 180 kg N /ha. In hill soils, the economic response to N has been observed up to 150 kg N/ha. In the black cotton soils of Deccan plateau and in red soils of Bihar, Orissa and Tamil Nadu, the economic responses have been obtained between 100-140 kg N/ha.