Spatio‐temporal variability in vine vigour and yield in a Marlborough Sauvignon Blanc vineyard

Abstract

Background and Aims Previous work has indicated that patterns of within-vineyard variation in vine vigour are stable in time and, in the case of spur-pruned vineyards, closely match patterns of variation in yield. However, whether this yield : vigour interaction also occurs in cane-pruned vineyards is uncertain. This work sought to better understand this issue in support of efforts to improve yield estimation in cane-pruned Marlborough Sauvignon Blanc. Methods and Results Vine vigour, measured as pruning mass, trunk cross-sectional area and using remotely sensed imagery, and the components of yield were measured in a 5.9 ha Marlborough Sauvignon Blanc vineyard on vines which had been pruned to retain either two or four canes. The results suggest that whereas patterns of variation in vine vigour are stable in time, and related to variation in the land underlying the vineyard, patterns of yield variation are neither temporally stable nor related to variation in vine vigour or the inherent underlying characteristics of the block. Conclusions For all practical purposes, variation in the yield of Marlborough Sauvignon Blanc within vineyard ‘zones’ identified on the basis of variation in vine vigour or soil properties can be regarded as random. Nevertheless, given a diversity of product offering, and because variation in vigour can have a marked impact on fruit composition, remotely sensed indices of vigour do provide a valuable basis for targeting sampling or sensor deployment aimed at yield estimation. Significance of the Study This work highlights the need to differentiate between spur- and cane-pruned vineyards in considering how vineyard variability should be assessed, and how the tools of precision viticulture and targeted management are applied.