Grape Days 2024 | Water use efficiency of 11 rootstocks under deficit irrigation | Braden Crosby

New adaptation strategies are required to deal with the changing climate and using more water-efficient rootstocks is a potential solution. This project investigates the effect of rootstock on 30-year-old Chardonnay vines (Clone 6) grown in the Renwick area of Marlborough.
Eleven rootstocks were assessed over two seasons (2023 and 2024) and the primary objective was to evaluate the rootstocks' effect on drought tolerance and water use efficiency in grapevines, along with canopy growth, yield and juice parameters.
The rootstocks showed a relationship between parentage and canopy size, pruning weights, canopy gaps and trunk cross-sectional area diameter. The relationship between rootstock and water use efficiency, yield and juice parameters was less clear, although Riparia x Rupestris rootstocks tended to have a slightly lower TA and malic acid level.
This was presented at Grape Days Marlborough 2024.