Effect of Cold on Grapes (2024)

LAKE ERIEVINEYARDS SHOWING EFFECTS OF WINTER COLD TEMPERATURES

-by LukeHaggerty, LERGP, Viticultural Extension Associate

PORTLAND, NEW YORK (April 21, 2015) -- Cornell Cooperative Extension Chautauqua County’s Lake Erie Regional Grape Program

Asthe season begins to change, and the landscape gets greener, we would like toforget about the recent harsh winter. For area grape growers, this is difficultas the past winter was particularly brutal for both man and grapevine.

February2015 will go down as one of the coldest on record pushing many grape vines pasttheir hardiness thresholds. On February 16th, early morning temperaturesreached damaging levels for most regionally grown grape varieties. NEWA weatherstations (http://newa.cornell.edu) recorded temperatures across the LakeErie region from -17^ᵒF to -29.9^ᵒF. These winter lows left many grape growers concerned aboutfreeze damage. In response, Lake Erie Regional Grape Program (LERGP)personnel combined efforts to determine the effects of the low temperatures onarea vineyards.

LERGPanalyzed over 15,000 grape buds to determine the scale of damage caused byfreeze. As expected, tender vinifera wine grapes like ‘Riesling’and ‘Cabernet Sauvignon’ received severe bud damage ranging from 70 to 95percent. Hybrid wine grapes fared slightly better with bud mortalityaverages from 40 to 90 percent. However, these types of grapes onlyaccount for 4% of the 18,000 acres of grapes grown in Chautauqua County.

Mostassessment efforts were concentrated on ‘Native’ varieties such as ‘Concord’and ‘Niagara’ which make up 95% of the county’s grape production. Concordgrapevines are relatively hardy compared to other grape varieties grown in theeastern US; a primary reason why the Concord industry has survived for so longin western NY. Freeze damage to Concord buds ranged from 20 to 80percent. In a typical winter, Concord buds receive between 10 to 15 percentfreeze damage.

There aremultiple forms of freeze damage that can occur. Damage can develop in thebuds, canes, or trunks. Bud damage will affect the current year’sproduction by killing the grape clusters forming in the buds. Trunkdamage, however, can set production back three-to-five years as the vine essentiallyneeds to regrow new trunks and the upper canopy which produces the fruit. Earlyassessment efforts were concentrated on bud damage and mortality as it isrelatively easy to assess even when the vines are dormant. However, it isnot until spring returns, and the sap is flowing in the vine, that trunk damagecan be assessed.

Earlyassessment of trunk damage in Concord vineyards looks promising whileassessment of the more tender wine grapes does not. The full extent of winterfreeze damage will not be known until the early summer months when vinesare in high demand for both water and nutrients. Injured trunks that cannotkeep up with the demand may collapse and die at this time.

The Februaryfreeze event has made the 2015 season a critical time for LERGP and CooperativeExtension to assist the Lake Erie grape industry. LERGP will continue toprovide sound, researched-based information to support all members of the grapeindustry in their efforts to deal with the effects of the brutal cold temperaturesof the past winter.

The Lake ErieRegional Grape Program is a cooperative effort between Cornell and Penn StateUniversities; the participating Cornell Cooperative Extension Associations ofChautauqua, Erie, Niagara and Cattaraugus Counties in New York and Erie Countyin Pennsylvania; and participating industry partners National Grape Cooperative(Welch’s), Constellation Brands and Walkers Fruit Basket. The LERGP extensionteam provides research-based educational programming for commercial grapegrowers throughout the year at venues across the Lake Erie grape belt. For more information on LERGP, call 716-792-2800 or visit our website at http://lergp.cce.cornell.edu/

PhotoCaption: Outer layer ofbark cut away and corresponding cross section showing varying degree of freezedamage in grapevine trunks (Left) severe damage, (Middle) moderate damage, (Right)no damage. (Photo courtesy L. Haggerty)

The Lake Erie Regional Grape Programis one of many programs offered by Cornell Cooperative Extension of ChautauquaCounty (CCE-Chautauqua). CCE-Chautauqua is a community based educationalorganization, affiliated with Cornell University, Chautauqua County Government,the NYS SUNY system, and the federal government through the United StatesDepartment of Agriculture’s National Institute of Food and Agriculture. Formore information, call 716-664-9502 or visit our website at www.cce.cornell.edu/chautauqua.Cornell University Cooperative Extension provides equal program and employmentopportunities.

Last updated July 26, 2019