|Cragin, Jacob - Boise State University|
|Keller, Marcus - Washington State University|
|Serpe, Marcelo - Boise State University|
Submitted to: American Society of Enology and Viticulture Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2012
Publication Date: 6/18/2012
Citation: Cragin, J., Keller, M., Serpe, M., Shellie, K. 2012. Disentangling dormancy and cold-hardiness in wine grape cultivars Cabernet Sauvignon and Chardonnay. American Society of Enology and Viticulture Annual Meeting Abstracts. 63rd ASEV Technical Abstracts/ pg. 131..
Technical Abstract: Cold-hardiness of bud and cane tissue was monitored throughout para, endo and ecodormancy in field-grown vines using differential thermal analysis to generate lethal temperature exotherms (LTE). Deacclimation and re-acclimation rates were measured during ecodormancy to determine the depth of dormancy at which deacclimation became irreversible. Seasonal LTE and ambient temperature data were input into a published dynamic thermal time predictive model of cold-hardiness and seasonal differences between observed and predicted values were used to assess its predictive accuracy for the climatic conditions of south-western Idaho. Cabernet Sauvignon and Chardonnay cane samples were collected monthly or biweekly from the USDA-ARS Parma, Idaho research vineyard beginning in September, prior to harvest. Percent and onset of budbreak of single-node cane sections (nodes 4-8) exposed to 25/20 °C (day/night) for 30 d were measured to determine stage and depth of dormancy at each sampling date. Deacclimation and re-acclimation were assessed at ecodormancy by determining LTE after exposing canes to forcing conditions and forcing followed by chilling conditions (336 h at 0 °C). Results showed no significant difference between cultivars in cold-hardiness during paradormancy and early endodormancy; however, during most of endodormancy, cultivar differences were significant with Chardonnay most cold hardy and requiring less accumulated chilling units. LTEs were strongly correlated with mean temperature at each sampling date from July 2011 through January 2012 (Cabernet Sauvignon r2= 0.81 Chardonnay r2=0.87).