Deficit irrigation and grafting effects on soil attributes, vegetative growth, yield components, and quality of ‘Crimson Seedless’ grapevines under a semiarid region

This study evaluated the combined effects of grafting and deficit irrigation (DI) on soil attributes, vegetative growth, yield components, fruit quality, and water productivity of 'Crimson Seedless' grapevines under semiarid conditions. It was hypothesized that the DI could enhance crop water productivity and fruit quality, especially when integrated with grafting, without a significant reduction in fruit yield. DI included five irrigation treatments: full irrigation (control), 75% of full irrigation over the season (D1), 75% of full irrigation except during the berries enlargement stage (principal growth stage 7, or BBCH 71-79), received water equivalent to the control (D2), 50% of full irrigation (D3), and 50% of full irrigation except during the berries enlargement stage, received water equivalent to control (D4), with and/or without grafting. The grapevines under deficit irrigation produced the highest crop water productivity, fruit soluble solid content (SSC), and total anthocyanins without significant impacts on fruit yield, except for D4 (severe deficit). Deficit irrigation applications saved 25%, 13%, 50%, and 26% of the water used for D1, D2, D3, and D4, respectively, compared with the control, resulting in decreased power consumption during vineyard irrigation and, subsequently, reduced irrigation costs. Moreover, soil porosity and hydraulic conductivity remained unaffected. In addition, grafted grapevines produced lower vegetative growth parameters but improved most fruit quality parameters without significantly affecting fruit yield. The present study confirmed that deficit irrigation could effectively save water and improve fruit quality without affecting fruit yield for grapevines in arid and semiarid regions. Furthermore, grafting on specific rootstock should be used as a practical approach for managing water deficit conditions.