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Vineyard Ice |
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Here in the mountains of Western North Carolina we often get late Spring frosts. The vines will be leafed out and the potential grape crop will be set. In order to protect the crop, some form of frost protection is needed. We use a sprinkler system. The system works on the principle of latent heat production. When water turns to ice, heat is produced in the freezing process. We use a gasoline fired irrigation pump to pump water up out of the creek through the underground pvc pipes and into the upright raised rain-bird sprinkler heads. The pump can run continuously for 8 hours before running out of gas. Once the vines have leafed out in the Spring we are on frost patrol paying close attention to the daily weather forecasts. If a forecast predicts the temperature to drop to freezing or below we set our alarm clocks for periodic checks; first at midnight, then at 2 am, etc. When the temperature reaches 36 degrees Bill starts the system. We usually only have to run it until just shortly after sunrise when the temperature climbs above the freezing mark. On one night in April of 2005, we ran the system well into the late morning hours. The temperature plummeted to 23 degrees F and took a very long time climbing back above 32. We were able to save about 50% of the potential harvest of both the table grapes and the vinifera. Unfortunately we did lose our only vine of Gamay. Below are pictures of the system at work that day. |
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Photo of Gamay vine leafed out and fully covered in ice from the sprinkler system. Photo was taken @ 8 am |
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Click on the link to view the pictures in a web album for larger size. |
