The Effect of Partial Root Drying on Antioxidant Activity in Different Agricultural Crops

Partial root drying (PRD) is a new irrigation strategy which applies alternating regimes of irrigation to half the root system while the other half dries out. Many published results showed that PRD may save water without significant effect on yield. The aim of this work was to compare the effects of PRD with full irrigation (FI) on yield and antioxidant activity in grape berry, potato tuber and tomato fruit. in both experimental conditions (field and polytunnel), the soil water content in FI treatment was kept close to field capacity, although in PRD treatment, 70o/o of the irrigation water in FI was uppti"a to one half of the root system, and irrigation was shifted according to soil water content decrease in the dry side of the root zone. At the end of the vegetation season, analyses of total yield of fruit and tubers and their quality were carried out. Antioxidant activity of tomato fruit ethanolic extract was evaluated against 2,2'-azinobis (3-eyhylbenzothiazoline-6-sulfonic acid) radical cation (ABTS'*) and expressed as Trolox (6-hydroxy-2,5,7,8-tetramethylchtoman-2- carboxylic acid) equivalent antioxidant capacity (TEAC)' In general, treatment differences in yield were not significant for either crop although WUE and anti,oxidant activity in the PRD treatments were higher than in the FI treatment for investigated crops. These results for all PRD-treated crops showed that PRD could be a useful strategy to save irrigation water without significantly sacrificing either the quantity or quality of yield.