Le Vigneron (Grape newsletter)
[One thing we know about Oklahoma weather is that we can never predict it. March of 2007 was the 2nd warmest recorded for the entire state - 8°F above normal. Some areas of the state were even warmer than the average. Northeast Oklahoma was 9°F above normal. All of this warm weather lead to much earlier than normal budbreak. At the OSU Experiment Station in Perkins we recorded budbreak of 'Chardonnay' on March 20. The early physiological activity of the vines predisposed them to damage from the freeze. The extreme cold of the freeze compounded the injury. Some areas of the state avoided the freeze entirely or could use management such as running irrigation to minimize any damage. Other portions of the state had no such luck. When temperatures reach 28°F or below for any appreciable length of time one should expect to see some injury to the vine. If one has access to a wind machine, heaters or overhead irrigation, then it is possible to alter the temperature in the vineyard and save the crop (and minimize vine injury). However, if temperatures reach 24°F or below, there is essentially very little a grower can do to stop damage from occurring. In light of the freeze, I expect to see a reduction in grapes harvested this year, especially from vinifera grapes. Grapes derived from V. vinifera are often non-fruitful on secondary buds. Hybrid and American grapes are often fruitful on secondary buds, with varying degrees of crop. Some cultivars this year seem to be somewhat prolific in spite of the freeze ('Vignoles', 'Cynthiana', and 'Chambourcin' to name a few). This spring freeze was unusual because of the warm March that preceded it and due to the coldness and duration of those cold temperatures. I have observed some permanent plant damage and even plant death, but in most cases that was on vinifera grapes. Some areas of the state may consider hybrid grapes as a more viable option in the future. ]
Fruit Review archives (.pdf): published 1995-2002
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