Calibrated, delayed-cane winter pruning controls yield and significantly postpones berry ripening parameters in Vitis vinifera L. cv. Pinot Noir

Background and Aims The postponement of spur pruning after budburst has recently been proposed as a simple and inexpensive way to delay sugaring, maintain acidity and contain yield in spur-pruned trellised grapes. Yet, no long-term data are available for the widely adopted cane pruning system. Methods and Results Mature field grown Vitis vinifera L. cv. Pinot Noir vines were subjected for three consecutive years to the following treatments: standard winter pruning (WP), double pruning (DP), where shortening and positioning of the selected cane is postponed, and late pruning (LP), where all pruning operations are postponed. Postponed pruning was performed when shoot growth from node 10 of the unpruned canes had reached an average stage of more than three unfolded leaves. Phenological and ripening dynamics, yield components and must composition were determined. Double pruning did not affect phenology and overall vine performance compared to that of WP. Conversely, LP significantly delayed ripening over 2 trial years; LP also slightly increased whole-vine and single-cane phenological variability, whereas yield per vine was reduced by 35% as compared to that of WP because of lower shoot fruitfulness. Conclusions If repeated over several seasons, late WP applied to a cane-pruned system when the distal part of the cane has already burst an average of three leaves can become effective at delaying phenology and extending maturity into a cooler season. Significance of the Study We have validated a simple technique suitable for preserving balanced must composition required for a range of sparkling wine styles.