Selecting rootstocks to improve vine performance and vineyard sustainability in deficit irrigated Monastrell grapevines under semiarid conditions

Regulated deficit irrigation (RDI) and partial root zone irrigation (PRI) were compared for five years, in field-grown mature Monastrell grapevines grafted on five different rootstocks (140Ru, 1103 P, 41B, 110R, and 161-49C), in the semiarid winegrowing region of D.O. Bullas, South Eastern Spain. Vines grafted on invigorating rootstocks (140Ru or 1103 P) showed the highest vigor, water productivity, and productive water use efficiency (WUEyᵢₑₗd), but at the expense of berry quality (lower berry quality indices, QI), compared to those on rootstocks of medium-low vigor (41B, 110R, and 161-49C). Vines grafted on 41B showed a moderate vigor-yield-efficiency-quality response, and this did not improve substantially the final berry quality. The least vigorous rootstocks (161-49C and 110R) gave lower yield, WUEyᵢₑₗd, and productivity ratios, but a significant improvement in long-term final berry quality. The PRI increased the yield and/or berry quality attributes, especially in low vigor rootstocks (161-49C, 110R) and high vigor rootstocks (140Ru, 1103 P), but not in the medium vigor rootstock 41B. In addition, PRI produced a beneficial increase in the nutraceutical potential for practically all rootstocks. The PRI vines grafted on 161-49C gave the lowest yield and WUEyᵢₑₗd, but the highest QI scores and the highest nutraceutical value, while PRI vines grafted on 110R had enhanced long-term yield, WUEyᵢₑₗd, and amino acid and resveratrol contents, with similar berry quality (QI) indices, compared to RDI vines. Both 161-49C and 110R seem good options to achieve a compromise between long-term yield-quality-efficiency and returns for the grower. The application of low water volumes (85-90 mm year⁻¹) with well-designed DI strategies was enough to maintain the vines in an optimum physiological state, obtaining moderate yields (7,400–9,900 kg ha⁻¹, for 161-49C and 110R) with high berry quality and nutraceutical potential for premium red wine production. Such an approach can serve as an adaptation measure in the face of climate change, to improve vine performance and enhance Monastrell vineyard sustainability under semiarid and water limiting conditions.