This is a summary of several years' data on mid-winter cold hardiness of selections and varieties from Bruce Reisch's grape breeding program at NYS Agricultural Experiment Station vineyards:
Checking bud mortality in your vineyard
Growers can determine roughly how many live or dead buds are present in vineyard to guide pruning decisions by collecting dormant canes in the vineyard and cutting buds open with a razor blade. Here are brief video presentations from the Finger Lakes Grape Program:
Evaluating Bud Injury Prior to Pruning (video, youtube)
Seasonal Bud Low Temperature Exotherms
With funding from Viticulture Consortium-East, the Lake Erie Regional Grape Program, Inc., and the New York Wine and Grape Foundation, we are posting bud cold-hardiness information for four representative varieties in New York, measured at commercial and Cornell vineyards in the Lake Erie, Finger Lakes, and Hudson Valley regions.
We have chosen Riesling, Cabernet Franc, Cayuga White, and Concord as representative varieties exhibiting a broad range of bud hardiness under NY conditions.
Vineyards will be sampled every two weeks from December 1 through March. Buds are subjected to differential thermal analysis (DTA), with approximately 30 buds total from the first 8 nodes of at least 5 canes per variety at each sampling date.
Most recent LT50 (Median Bud Freezing Temperature) values for each region are listed in separate tables below.
Clicking on a variety name will bring up individual graphs of minimum/maximum temperatures and seasonal change in bud freezing temperatures.
Seasonal Bud Mortality for each variety/site can also be found on the graphs.
For previous three years' information, see:
NYS Agricultural Experiment Station (Weekly samples)
Finger Lakes - Commercial Vineyards
|4/15/13||East Keuka||Cabernet Franc||19.3||14.9||10.8|
|4/15/13||East Seneca||Cabernet Franc||-1.0||-4.9||-8.4|
|4/15/13||West Keuka||Cabernet Franc||18.4||13.6||9.5|
|4/15/13||West Seneca||Cabernet Franc||21.8||17.8||7.5|
|4/15/13||West Cayuga||Cab Franc||13.3||9.5||-6.9|
Lake Erie Region (West To East)
|4/16/13||Traminette|| 19.4 ||12.9||10.8|
Bud hardiness testing in other regions:
Thanks to the Lake Erie Regional Grape Program, Inc. and the New York Wine and Grape Foundation for funding this project. Special thanks to Lynn Mills and Markus Keller of Washington State University for sharing the template used to generate the graphs.