RESPONSE OF “PACIFIC ROSETM” APPLE TO PARTIAL ROOT IRRIGATION

Abstract

Apple trees are grown in areas were irrigation water is almost always a limiting factor; therefore, new irrigation techniques for saving irrigation water need to be developed and tested for a sustainable production system for this fruit crop. During the 2000-01 growing season, we studied the effect of partial root irrigation (RPR) on tree water status, gaseous exchange, and yield and fruit quality of “Pacific RoseTM” apple trees grown in the humid region of New Zealand. Treatments included commercial irrigation (RC, control) and RPR. In general, tree water status and gaseous exchange were the same between treatments. Yield, transversal trunk section (STT), yield efficiency (yield/STT) per tree, and average fruit weight were the same between treatments, but efficiency of irrigation water use was significantly improved in tress under RPR, when compared to trees under RC. Using RPR resulted in savings of 0.15 mega-liters of water per hectare. Fruit quality, in terms of dry matter concentration, starch index, total soluble solid concentration and fruit color, was the same between treatments. Therefore, RPR could be suggested as a water-saving practice without detrimental effects on yield and fruit quality in humid environments; however, research on RPR should be carried out in arid environments.