Water requirement, yield and fruit quality of grapefruit irrigated with high-sulphate water

Abstract

SummaryThe effect of irrigation with different amounts of high-sulphate water on the growth and yield of grapefruit trees was studied during a six-year period. Irrigation with 600–700 mm of water over the irrigation season, corresponding to 50–60% of pan evaporation, proved sufficient for high yield. Under-irrigation increased soil salinity associated with the highly soluble salts, and reduced tree growth (girth increase and seasonal vegetative growth). Although the fruit growth of the stressed grapefruit trees was delayed and yield was reduced, total soluble solids and acid percentage of the juice were increased significantly. Irrigation with the higher amounts of high-sulphate water resulted in gypsum precipitation/dissolution and a low persistent soil salinity which could not be leached.