Water production functions for potato (Solanum tuberosum) under different irrigation methods

Abstract

A field experiment was conducted at research farm of Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra during rabi season of 2006 to 2008, to develop water production functions for potato (Solanum tuberosum) under different irrigation systems, viz. sprinkler, microsprinkler, drip and surface irrigation system. Each irrigation method except drip was combined with 5 irrigation regimes, i.e. IW/CPE ratio of 1.40, 1.20, 1.00, 0.80 and 0.60. In drip, variable wetted area factors, viz. 1.30, 1.10, 0.90, 0.70 and 0.50 were applied as irrigation regimes. The sprinkler method was found superior to all other methods in terms of tuber and haulm yield, water use and fertilizer use efficiency. Potato tuber yield increased with increasing irrigation level from 0.60 to 1.20 IW/CPE (in drip 0.5 to 1.10 wetted area) and then decreased at 1.4 IW/CPE ratio (in drip 1.30 wetted area) in all the irrigation methods. However, haulm yield of potato was found highest in 1.4 IW/CPE ratio. The highest water-use efficiency (7.72 q/ha-cm) was recorded with 0.50 wetted area treatment in drip irrigated plots. The second order quadratic water production functions developed to estimate potato yield were used to find optimum depth of irrigation under different methods of irrigation. For sprinkler and microsprinkler methods 3.50 cm depth of irrigation at 25 mm CPE and for surface 6.00 cm depth of irrigation at 50 mm CPE was found optimum. For drip method of irrigation wetted area factor of 0.90 was found optimum.