Fruit Growth and Dry Matter Accumulation in Grapefruit During Periods of Water Withholding and After Reirrigation

Abstract

Changes in volume, fresh weight and dry matter (DM) contents were followed in fruits from girdled and non-girdled branches borne on regularly irrigated (RI) as well as water-stressed (S) trees. Water stress was imposed by withholding irrigation for various periods. The results indicate that, even during prolonged periods of drought, DM accumulation in fruits on S trees was only slightly impaired, even when fruit volume growth was reduced to zero or even to shrinkage. After irrigation was resumed, fruits from S trees grew faster than those from RI trees, indicating that some of the DM which had accumulated was available for volume growth. The possibility of using the rate of DM accumulation in the fruit as an indicator for the timing of irrigation is discussed.