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Midwinter Bud Hardiness of Selected Cultivars

Incorporating cold-hardiness into new grape varieties is an important goal of the Cornell Grape Breeding Program. For this reason, Bruce Reisch's program routinely does bud freezing runs as part of his evaluation of selections from the program. They are also run against industry standards and varieties from other programs. The tables below summarize results of mid-winter evaluations of bud freezing temperatures.

The LT50s shown here are based on collection of 30 to 50 buds from each variety. LT50 is the median bud freezing temperature based on this collection. Each variety is tested one or two times during the most hardy mid-winter phase (January - mid February). Here we report results from this year's runs, as well as averages from up to 15 previous years of testing.

Many sources of variability affect bud freezing results on a given day - or in a given year, so the best way to look at these numbers is 'as a group' to indicate relative cold-hardiness. An LT50 of - 15 degrees F does NOT mean the buds are 'hardy down to -15'. Because the breeding plots are not managed like commercial vineyards, the vines' performance may differ from a commercial situation.

Mid Winter Low Temperature Exotherms

Recent Hybrids and NY Selections

Selection LT50 2010/11 (F) LT50 Multi-yr Ave. (F) No. Years
Cayuga White  -12.7 -11.54 21
Chambourcin -12.7 -11.74 16
Chardonnay (control)* -11.8 -11.8 13
Chardonel -9.2 -10.9 10
Corot noir -18.9 -15.8 14
Melody - -13.1 10
Noiret -13.1 -14.3 14
Aromella -16.7 -16.04 18
NY81.0315.17 -13.1 -13.8 13
Arandell -13.4 -12.42 10
Traminette -14.0 -14.9 14
Valvin Muscat -14.5 -14.2 14
Valvin Muscat/Grafted - -14.3 11

*Chardonnay (control) has been de-fruited in recent years which may have improved bud hardiness.
** Note: NY95.0301.01 (Robbins Farm) is a 'no-spray' block, with no fungicide sprays applied.

Cold Hardy Hybrids (Minnesota and Swenson Varieties)

Selection LT50 2010/11 (F) LT50 Multi-year Ave. (F) No. Years
Frontenac -17.9 -17.8 11
Frontenac gris - -18.63 5
La Crescent -21.9 -18.2 12
Louise Swenson - -21.8 1
Marquette -18.7 -17.9 8
Prairie Star - -20.2 2
Sabrevois - -20.1 1
Skujins 675 - -19.5 2
Somerset Seedless - -19.3 1
Trollhaugen - -20.5 1

Hybrid Red Wine Grapes

Selection LT50 2010/11 (F) LT50 Multi-year Ave. (F) No. Years
Baco noir -16.4 -17.0 4
Chancellor -13.5 -15.2 6
De Chaunac -14.7 -15.7 7
GR7 -18.9 -16.6 13
Leon Millot - -14.9 2
Marechal Foch -19.3 -17.7 6
Vincent - -12.2 2

Hybrid White Wine Grapes

Selection LT50 2010/11 (F) LT50 Multi-year Ave. (F) No. Years
Aurore -18.3 -15.6 6
Ravat 34 -13.8 -15.4 8
Seyval/5C -16.2 -13.3 7
Ventura -17.6 -18.9 4
Vidal blanc -12.3 -12.5 6
Vignoles -6.8 -11.8 6

Native Grapes

Selection LT50 2010/11 (F) LT50 Multi-year Ave. (F) No. Years
Catawba -13.7 -13.9 6
Concord -19.1 -18.0 15
Niagara/5C - -17.7 4

Seedless Table Grapes

Selection LT50 2010/11 (F) LT50 Multi-year Ave. (F) No. Years
Canadice - -16.4 2
Einset Seedless - -16.0 5
Himrod -14.7 -14.3 6
Interlaken - -9.0 2
Jupiter -9.3 -10.1 3
Lakemont - -10.3 2
Marquis -12.6 -12.6 10
Reliance - -15.4 3
Thomcord -7.0 -10.7 4