Does partial root-zone drying have advantages over regulated deficit irrigation in pear orchard under desert climates?

Abstract

The impacts of partial root-zone drying (PRD) and regulated deficit irrigation (RDI) with the same irrigation volume on vegetative and fruit growth and leaf physiological parameters of pear trees planted under desert climate were evaluated. The experiment involved RDI and PRD treatment, irrigated with the 50 % replacement of pan evaporation (Ep) during the slow fruit growth stage, and 80 % replacement of Ep during rapid fruit enlargement stage. Control trees were irrigated with the 80 % replacement of Ep during the whole growing season. No significant differences in the soil and leaf water status between PRD and RDI were observed, which resulted in the similar vegetative growth, fruit yield and leaf gas exchange between PRD and RDI trees. In conclusion, the leaf gas exchange, the vegetative and fruit growth of pear trees planted under extreme drought condition were mainly controlled by the irrigation volume rather than the irrigation method. Therefore, application of the PRD technique was not recommended in the extremely arid region compared with the RDI strategy.