Eco-Physiological and Productive Response of Deficit Irrigated Potatoes

Abstract

A comprehensive study on both the eco-physiological and productive response of potatoes to dynamic deficit irrigation is lacking. Therefore, the aim was to study, over two growing seasons and on two potato cultivars—Arinda and Timate, the effects of five irrigation regimes (I0–dry control, I1—irrigated control, I2—supply 100% of the maximum evapotranspiration—ETm from tuber initiation up to 50% of tuber growth and 0% ETm from 50% to the end of tuber growth, I3—supply 100% of ETm from tuber initiation up to 50% of tuber growth and 50% ETm from 50% to the end of tuber growth, I4—supply 100% of ETm from tuber initiation up to 50% of tuber growth and 75% ETm from 50% to the end of tuber growth) simultaneously on the crop physiology (via chlorophyll fluorescence and leaf gas exchange traits), above-ground biomass yield, tuber yield and its components, irrigation water use efficiency (IWUE), source/sink ratio and tubers’ dry matter content. Regardless of cultivars and seasons, in I3 and I4 for eco-physiological and productive traits, values comparable with I1 were found. Compared to I1, I2 reduced tuber yield by about 18% but increased the IWUE by about 110%, saving a high amount of irrigation water (about 1500 m3 ha−1 per season). Arinda appeared more susceptible than Timate to water deficit in the second part of tuber growth, namely I2, from an eco-physiological point of view, but no differences between cultivars were found from a productive point of view. It was possible to effectively apply dynamic deficit irrigation to save irrigation water without compromising yields strongly.