Aim
This study investigated over three seasons, the influence of five pruning dates on yield components, grape composition, phenology and carbohydrate reserves in the variety Merlot, grown in a warm climate area.
Background & Methods
Dormant cane pruning has a great impact on vineyard management both in terms of labour costs and the time required to complete this field operation in the absence of mechanisation. In this study, researchers investigated over three seasons the influence of five pruning dates on yield components, grape composition, phenology and carbohydrate reserves in the variety Merlot, grown in a warm climate area. Pruning was conducted soon after harvest, at the end of leaf fall, two bud dormancy stages and vine bleeding.
Results
Early pruning, carried out a few days after the grape harvest, did not significantly affect vine productivity or grape composition in the next season compared to full winter pruning. Similarly, non-structural carbohydrate concentration in trunk and roots showed no difference just before budburst, no matter the timing of pruning. Late winter pruning at vine bleeding slightly postponed budburst and flowering; it also delayed veraison in one out of two years of observation without affecting grape maturity.
Significance of the study
The findings suggested that, in a warm-climate area where leaf fall occurs within a ten-week period after harvest, early pruning had no detrimental effects on reserve accumulation in storage organs and, therefore, in vine yield and grape composition in the next harvest, thus allowing viticulturists to operate winter pruning over an extended interval of time.
Note that this study was conducted over three vintages on one variety in Treviso, Italy. The results cannot necessarily be extrapolated to any other warm climate area. A longer observation period would also be required to assess possible carry-over consequences of early pruning in Merlot.
Reference
Falginella, L., Gaiotti, F., Belfiore, N., Mian, G., Lovat, L., & Tomasi, D. (2022). Effect of early cane pruning on yield components, grape composition, carbohydrates storage and phenology in Vitis vinifera L. cv. Merlot. OENO One, 56(3), 19–28.
This abstract is republished in its original form, with headings inserted, as permitted by the following Creative Commons licence: https://creativecommons.org/licenses/by/4.0/
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