Irrigation water saving during pomegranate flowering and fruit set period do not affect Wonderful and Mollar de Elche cultivars yield and fruit composition

Abstract

Adult pomegranate trees [Punica granatum (L.) cultivars Wonderful and Mollar de Elche] were submitted to different irrigation treatments during the 2015 and 2016 seasons. Control (T0) plants were drip irrigated to guarantee non-limiting soil water conditions; T1 plants were subjected to water withholding during flowering-fruit set period for 64 (2015) and 53 (2016) days, resuming irrigation as in T0 plants subsequently. In both cultivars, the results demonstrated that during the flowering-fruit set period the sensitivity to water stress is very small, being possible to suppress or reduce irrigation (at least, while plant water status maintains similar levels to those reported in this study) without affecting marketable yield and fruit size and composition. Thus, this period can be considered as a clearly non-critical period. In this sense, water saving was around 19–30% and water productivity (WP) increased around 4–14% in Wonderful and 10–16% in Mollar de Elche. Water stress increased flowering, but not the number of viable hermaphrodite flowers, and decreased shoot growth (TSG), which could favour a compensatory young fruit growth when irrigation was resumed due to a shift in the carbon allocation pattern. This WP increase, the reduction in pruning cost (TSG decrease), and the redder arils in T1 plants were key aspects to increase consumers’ acceptance and farmers’ crop revenues.