2019/2020 Nova Scotia Wine Grape Bud Hardiness Report no. 3: December 9 – 10

Citation

2019/2020 Nova Scotia Wine Grape Bud Hardiness Report no. 3: December 9 – 10

Abstract

A wine grape bud hardiness report is generated and distributed to the Grape Growers of Nova Scotia (GGANS) membership on a bi-weekly basis throughout the dormant season. The bi-weekly survey is performed on 3 vinifera cultivars (‘Chardonnay’, ‘Riesling’, ‘Pinot Noir’) and 2 hybrid cultivars (‘L’Acadie Blanc’, ‘Marquette’) and involves 10 grower collaborators for a total of 23 varietal blocks in total. Each report uses a table to show the latest low temperature exotherm (LTE) levels for the present and past weeks. The report also includes comments highlighting observations over the last reporting period, a plot showing the change in LTE values throughout the season, the historical 100 year minimum values and the present year’s minimum values. Three times throughout the season (early, middle, late) 11 “extra” varieties (‘Baco Noir’, ‘Chenin Blanc’, ‘Geisenheim’, ‘Leon Millot’, ‘Lucie Kuhlman’, ‘New York Muscat’, ‘Pinot Gris’, ‘Sauvignon Blanc’, ‘Seyval Blanc’, ‘Seyval Blanc’, ‘Vidal Blanc’, ‘Ortega’) from 22 additional varietal blocks are also reported. Most bud hardiness values have continued to drop but recent temperature trends have slowed the acclimation rate considerably in comparison to other years. This is probably due to average temperatures, for the first 10 days of December, being approximately 3 °C warmer than normal. This trend is not likely to continue for much longer but forecasts call for this to continue through the weekend. Of particular interest is the hardiness value for Marquette as our estimates show it de-acclimating by almost a degree. Last year we observed a similar response in this variety in December and January. Although Marquette is considered to be a very hardy variety, it may be sensitive to the cyclic temperature trends that we are currently experiencing.

Publication date

2019-12-10

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