Effect of conventional irrigation and alternate rootzone drying with sufficient or deficient irrigation water on the production of Marsh seedless grapefruit.

摘要

The partial root zone drying (PRD) technique by which water is delivered alternately on either side of the tree, and conventional irrigation (CI) where water is applied on both sides, combined with sufficient or deficient water, were tested with Marsh seedless grapefruit (Citrus paradisi) in a field experiment conducted in Cyprus. Soil moisture increased with increasing amount of water applied and its fluctuation was less with CI and greater with PRD, especially in the surface soil layer. The mode of water application did not affect the yield or fruit quality, but decreasing amount of water affected both of them negatively. A 40% reduction in the amount of irrigation water applied decreased the yield by 20.9%, while a 20% reduction in irrigation water reduced yield by 14.0%. Yield reduction was mainly due to the production of smaller fruits and to a lesser extent, of fewer fruits. When the water requirement was fully met, larger fruits with thinner peel were produced. Therefore PRD did not offer any advantage at any level of water application in this study.