Effects of partial root drying on strawberry fruit

Abstract

Partial root-zone drying (PRD) is a well-established agricultural technique used to conserve water. Nitrogen plays a role in modifying both PRD-associated signaling and fruit quality. Here, we report the combined effects of PRD and nitrogen availability on water relations and fruit quality of strawberry plants (Fragaria × ananassa). Plants were subjected to PRD or common water deficit (DW) treatments with or without extra nitrogen supplied. PRD treatment resulted in a dramatic decrease in leaf conductance, whereas it had little effect on changes of leaf water potential. Strikingly, the inhibitory effect of PRD on leaf conductance was enhanced by nitrogen application. In the absence of nitrogen application, but not in its presence, PRD caused a significant decrease in fruit size. PRD did not improve fruit quality in comparison with its well-watered control; however, PRD in combination with nitrogen application resulted in increases in fruit firmness and vitamin C, soluble solid, and reducing sugar content, as compared with the control without nitrogen application, suggesting that PRD and nitrogen availability may jointly improve strawberry fruit quality formation. These findings provide guidelines for optimizing irrigation regimes to improve water use efficiency and fruit quality in strawberry farming.