Refrigeration of the Root Zone to Delay Budbreak in Grapes

• Published in: HortScience Vol. 35; no. 4; pp. 562 - 562b
• Main Authors: Graham, J.H, Montague, D.T, Durham, R.E
• Format: Journal Article
• Language: English
• Published: 01-07-2000
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/HORTSCI.35.4.562C

Grapes grown in West Texas are especially susceptible to freeze damage during spring deacclimation and budbreak. This experiment was undertaken to evaluate whether refrigeration of the root zone would delay budbreak in two grape cultivars, `Chardonnay' and `Cabernet Sauvignon'. The experiment was conducted under greenhouse conditions using 1-year-old grafted plants planted into containers in water bath chillers to cool the root zone. Three root-zone temperatures were maintained: 7.2 °C, 1.7 °C, and a nonchilled control. The experiment followed a randomized split plot, with main plots being temperatures and the sub-plots being genotype, and the experiment was repeated once. Evaluation of budbreak was performed on a daily basis. Other data collected included shoot dry weight and root dry weight with soil, water, and air temperatures recorded using type T thermocouples (copper-constantan) attached to a datalogger. The experiments indicated that budbreak could be delayed in both varieties by the refrigeration of the root zone by an average of 1 to 2 days when comparing the 1.7 °C treatment with the nonchilled control. The refrigerated treatments of `Chardonnay' also tended to show a prolonged budbreak over time. This finding may be significant since `Chardonnay' generally exhibits budbreak relatively early compared to other grape varieties and a prolonged budbreak may allow some buds to escape spring frost injury.