Yield and Fruit Quality in Processing Tomato under Partial Rootzone Drying

摘要

Water resources are limited worldwide and there is a need to develop water-saving irrigation practices. Here we applied partial rootzone drying (PRO) to 'Peto-pride' processing tomato plants with the alternate sides of the root system (RS) being exposed to various extents of soil dryness. The treatments were: daily full irrigation (FI) in both sides of RS considered as the control; and irrigating only one side of the RS for two (PRD_2), four (PRD_4), and six (PRD_6) consecutive days before irrigationwas shifted over to the dry side of the RS for the same periods. Leaf water potential, photo-synthetic rate, total fresh mass of fruit and total dry mass of fruit significantly reduced in PRD treatments relative to FI. But irrigation water-use efficiency was improved in the PRD treatments. A lower percentage of dry mass was partitioned into the PRD fruit, which had lower fruit water content and higher total soluble solids concentration than the FI fruit. Fruit skin colour was the same for all the treatments. Blossom-end rot incidence was higher in PRD fruit than the FI fruit although their calcium concentration was the same. PRD saved irrigation water by 50 %, but total dry mass of fruit was reduced by 23 %. However, the considerable saving of water could make PRD feasible in areas where water is scarce and expensive.