Supplemental irrigation to save water while growing cactus pear in semi-arid regions†

Climate change will compromise food access by causing water shortages for agricultural purposes. Supplemental irrigation (SI) was explored for its effect on crop water use, fruit yield, water use efficiency, water productivity, mean fruit mass and fruit size distribution of four cactus pear cultivars. The irrigation treatments were: non-irrigated (NI) rainfed control, SI and full irrigation (FI). The cultivars were: 'Cristalina' (Opuntia albicarpa Scheinvar), 'Amarilla Olorosa' (O. spp.), 'Roja Lisa' (O. ficus-indica L. Mill.), and 'Dalia Roja' (O. spp.). The experiment was conducted in a split-block design. The SI treatment saved water, in a 3-year-average, by 52% for 'Cristalina', 51% for 'Roja Lisa' and 52% for both 'Amarilla Olorosa' and 'Dalia Roja'. This resulted in a reduction in crop water use by 38% for 'Cristalina', 42% for 'Roja Lisa', 39% for 'Amarilla Olorosa' and 40% for 'Dalia Roja'. For SI, plant-relative water content and fruit growth were similar to the FI plants. SI plants maintained fruit yield, mean fruit mass and marketable fruit size at the level of FI plants, while it improved efficiencies of water use and water productivity. SI is therefore a feasible irrigation strategy for cactus pear for those areas where water availability is limited for agricultural activities. (c) 2020 John Wiley & Sons, Ltd.