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Bud Freezing Temperature Monitoring for 2015-2016 Underway

Grapevine buds gradually gain and lose cold-hardiness as temperatures fall and rise during the dormant season (Figure from Zabadal et al., 2007).

Grapevine buds gradually gain and lose cold-hardiness as temperatures fall and rise during the dormant season
(Figure from Zabadal et al., 2007).

Since the winter of 2009-2010, Cornell grape extension programs have been collecting and freezing buds from selected varieties (Concord, Riesling, Cabernet Franc, Noiret, and selected other varieties) in the Finger Lakes, Lake Erie, and Hudson Valley to provide information on potential bud injury to NY growers.

At the NYS Agricultural Experiment Station in Geneva and Hudson Valley Research Lab in Highland, we have been doing bud freezing runs weekly since November 1. As of January 4, we have started doing biweekly collections from 30 vineyards in the Finger Lakes, six in the Lake Erie region, and one in the Hudson Valley. The most current results (January 19) are posted in tables that list the 10%, 50%, and 90% bud freezing temperatures (also known as the LT10, LT50, and LT90; LT stands for ‘Lethal Temperature’). Along with the tables, we generate a figure showing the daily min/max temperatures and the measured LT50 for the entire season.

Along with the current season’s LT50 (black line), we are posting the LT50 from the previous season (blue line), and the predicted LT50 (red line) derived solely from minimum/maximum temperatures. This is a model developed at Washington State University.

We will be posting data at our bud hardiness data page regularly through early April, 2016.

A table summarizing the cold hardiness of select varieties bred for northern climates provides lethal temperature data of buds in choosing varietial selections for cold site plantings.

Cut buds placed on thermocouples for placement into in a controlled-temperature freezer.

Cut buds placed on thermocouples for placement into in a controlled-temperature freezer.

Our thanks to the New York Wine and Grape Foundation and the Lake Erie Regional Grape Program, Inc. for funding this project.

Article by Tim Martinson , Senior Extension Associate , NYS Agricultural Experiment Station