University of Nebraska
Viticulture Program
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2008 Reports will be posted as soon as needed. You might take this time to review the "Suggested Actions" Below.
The Freezes of 2005
April 29, 2005 Friends, I hope this does not get to be a regular event, but... Freeze tonight. I think you all know the drill. Use of fires or air movement devices are called for if you have leaves exposed and your vineyard might get below 30 degrees F. 28 degrees things can start to get ugly. Areas North and West of Omaha are at the highest risk in Eastern NE. Washington County, you are borderline, Saunders and Dodge, watch out. Dick K, Russ S. your are at great risk tonight, Bruce W/Bill S, Rich M, Gene H, and DeeAnn H, you folks in Washington county are at moderate risk. Expect temps a couple degrees below what is measured in the cities. Your site may be better or worse than others based on its own characteristics. What happened on the last freeze may not be true on this one, although they look very similar. I will be setting up my fires and then going out at 230 to baby-sit the vineyard and will light the fires if any temps get down to 30. Here are the NOAA numbers for tonight. You can access their website at: http://www.crh.noaa.gov/oax/digital.shtmlCity: Min temp, winds speed/direction Omaha: 32, 5-6 NW
April 28, 2005 Rich Mullins vineyard ---
I took the pump off of my air blast sprayer and run the fan all
night from 5:30 p.m. tp 5:30 a.m. The coldest temperature at the top of
the hill on our digital thermometer was recorded at 29.9 degrees. At the
bottom of the hill the temperature was 3 degrees warmer.
Too early to determine what losses we had.
Will check tonight when I get off work.
Jim Shaw
April 23, 2005 First Assessment of Freeze Damage at Czechland Vineyards, Wilber NE The freeze on Saturday night, April 23rd saw low temperatures in the vineyard north of Wilber range from 24F to 29F in different locations. The height of the cordons and the location in the vineyard made a significant difference in freeze impact. The range of temperatures in such a small area surprised us at the time we were reading them, but by Monday, the damaged seemed to mirror the temperature readings. Ours is a young vineyard, two and three year old vines. We attempted to protect the three-year olds in hopes of getting our first partial crop this year. Since we're new to this, we tried a lot of things to get heat under the St. Croix and water or ice on the Dechaunac varieties. In addition, we covered a few of the Dechaunac (on VSP) with sheet blankets and sprayed several layers of water (ice) over the Dechaunac with our field sprayer. The ice was thick on the wires, plants and leaves of all the Dechaunac, and those few plants covered by blankets .... the blankets were soaked and froze solid with no water or ice on the plants underneath. Our two and three year old Traminette (grafted on 3309) were purposely not pruned as yet, all were just budding or with small leaves and appear not to be injured severely. We did try and coat the three-year old Traminette with ice, but not nearly as thick as we concentrated on the Dechaunac. I think our decision not to prune this variety (based on last year's freeze damage lesson) saved the day for our Traminette. To put heat under the St. Croix, we used open Weber charcoal grills spaced about 50 feet apart with lots of firewood. We burned them from 2:30 a.m. until 7:00 a.m. We also tried large propane heaters and every gas engine (mowers, generators, etc.) we had sitting among the vines, but by far, the best heat producers were the wood fired kettle grills. Where they were at, no damage can be found on the GDC St. Croix. We walked our vineyard Monday evening and the damage wasn't near as bad looking as I was prepared to see. We'll know more of course as the regrowth continues. The Dechaunac looked the worst of all, but they are supposedly fruitful on the second bud whereas most others are not, so I hope we get some crop there. There was no difference between the blanketed and non-blanketed plants, all leaves were burnt brown. The rows of St. Croix looked great where the kettle grills were placed, but the bordering rows upwind had about 40% injury on many plants, indicating the heat didn't move west or north into the very slight breeze. The Traminette didn't appear to be badly damaged at all, even on the non-water-sprayed two year old plantings up the hill. None of these had been pruned. The pruned two-year old Concords had maybe only 10% damage, the rest looked fine to me and we hadn't done anything to prevent them from freezing. The Edleweiss looked like maybe a third of the leaves burned, many looked just fine. The two-year old Frontenac up higher on the hill appeared about like the Edleweiss, 30% of the leaves blackened, but most appeared still normal. We did nothing to prevent freezing on the Concords, Edleweiss or Frontenacs. On all the two-year old plants, the freeze probably helped us out like last year ..... killing off many fruit clusters so we don't have to spend as much time removing them all from these young plants. By this next weekend, if we get some warm growing weather, it'll be easier to make a loss assessment. I'll report again if it appears to differ significantly from this first look. The frost last night (Tuesday, April 26th) saw low temps of only 30F and we're not expecting damage from it (I hope).
Jim Emal
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The InThe Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln. It is the policy of the University of Nebraska-Lincoln not to discriminate on the basis of gender, age, disability, race, color, religion and marital status, veterans status, national or ethnic origin or sexual orientation.l Resources, University of Nebraska-Lincoln. It is the policy of the University of Nebraska-Lincoln not to discriminate on the basis of gender, age, disability, race, color, religion and marital status, veterans status, national or ethnic origin or sexual orientation.
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