Crop water production functions for potato (Solanum tuberosum) in north eastern hilly region of Meghalaya, India

Crop water production function (CWPF) relates crop yield to the amount of water applied for growing of crop and helps in planning deficit irrigation strategies. This study is undertaken to develop the CWPF for potato crop through a field experiment with irrigation treatments considering four regimes of maximum allowable depletion (MAD), viz., 45%, 60%, 75% and 90%. The experimental layout was developed with a split-plot design, where irrigation levels were main-treatments and three potato varieties, viz., Kufri Jyoti, Kufri Megha and Kufri Giriraj, were considered as sub-treatments with three replications. In every treatment, amount of water applications was monitored and yield of harvested potato was recorded, which were finally subjected to regression analysis. A satisfactory CWPF for potato in the form of a quadratic equation based on value of coefficient of determination (R² = 0.98) was developed. Among the three varieties, var. Kufri Jyoti resulted in the maximum potato yield of 13.73 t ha^-1 and the highest water productivity of 54.50 kg ha^-1 mm^-1. The CWPF developed in this study is useful to water resources managers and scientists to assess the potato yield under limited water availability conditions under hilly terrain of North Eastern Hilly Region of India.