Author
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Shellie, Krista |
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Submitted to: Groupe d'Etude des Systèmes de Conduite de la Vigne
Publication Type: Proceedings Publication Acceptance Date: 6/17/2005 Publication Date: 8/17/2005 Citation: Shellie, K. 2005. Vine water stress severity in Vitis Vinifera L. cv. Merlot: impact on yield components, berry and wine composition. Groupe d'Etude des Systèmes de Conduite de la Vigne. 2:534-539. Interpretive Summary: Technical Abstract: Own-rooted, four year old Merlot vines were exposed to four differential, evapotranspiration based, irrigation regimes: low, medium, or high vine water stress from bloom to veraison, or high preveraison stress altered to a medium level from veraison to harvest (high-med). This multi-year trial was situated at a commercial vineyard in southwestern Idaho, USA (latitude 43°28’N, longitude 116°42’W, elevation 841 m). Weekly midday leaf water potential values detected differences in vine water stress among treatments within three weeks after start of differential irrigations. Vines from high water stress plots had lower yield, smaller berry size, lower cluster weight, and less trunk growth than vines from low water stress plots. Fruit harvested from high water stress plots had lower titratable acidity and produced higher intensity wine than fruit from low water stress plots. Altering high preveraison stress to a moderate level from veraison to harvest resulted in similar cluster weight, seasonal trunk growth, and wine intensity as low water stress vines. The amount of water provided to these high-med plots was similar to high stressed plots in the pre-veraison period, to medium stressed plots in the post-veraison period, and about 50% less than low water stress plots. Results suggest that desirable vine and fruit attributes can be manipulated using less supplemental water by inducing a high preveraison stress that is altered to a moderate level from veraison to harvest. A biological based indictor of vine water status that is more sensitive than midday leaf water potentials would facilitate irrigation scheduling to manage severity and timing of imposed vine water stress. |
