Ohio Grape-Wine Electronic Newsletter

Editor: Imed Dami, PhD
Assistant Professor and Extension Viticulture Specialist
Department of Horticulture and Crop Science
Ohio Agricultural Research and Development Center
1680 Madison Avenue
Wooster, OH 44691-4096
Phone: (330)-263-3882
Fax: (330)-263-3887
E-mail: dami.1@osu.edu
 www.oardc.ohio-state.edu/grapeweb/

 
20 April 2007
 
 
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 Content:

Easter Freeze Update
Pre-Planting Care of Vines
OSU Viticulture Short Course
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 Easter Freeze Update
By: Imed Dami, HCS-OARDC
 
Many of our grape growers in central and southern Ohio reported sub-freezing temperatures in the low 20s and sometimes high teens which lasted for almost a week (April 4-April 10) across the state. Temperature recorded at OARDC and its satellite stations in northern (Kingsville) and southern (Piketon) are reported in the following table.
 
kingsville 
Date    Max Air Temp    Min Air Temp
    
4/1/2007 65 52
4/2/2007 57 41
4/3/2007 78 36
4/4/2007 60 29
4/5/2007 30 24
4/6/2007 28 24
4/7/2007 29 23
4/8/2007 31 26
4/9/2007 37 29
4/10/2007 41 25

Wooster
Date    Max Air Temp    Min Air Temp
    
4/1/2007 69 54
4/2/2007 68 52
4/3/2007 76 48
4/4/2007 59 26
4/5/2007 28 23
4/6/2007 30 23
4/7/2007 26 19
4/8/2007 31 22
4/9/2007 37 29
4/10/2007 46 27

PIKETON 
Date    Max Air Temp    Min Air Temp
    
4/1/2007 76 58
4/2/2007 76 52
4/3/2007 82 44
4/4/2007 60 33
4/5/2007 39 29
4/6/2007 41 26
4/7/2007 35 24
4/8/2007 39 29
4/9/2007 44 30
4/10/2007 55 23
 
Early grape varieties have already broken buds by then due to unusual warm March which led to extensive damage. Native varieties (e.g. Concord) sustained the most damage, followed by hybrids (e.g. Foch, Dechaunac). Vinifera varieties were the latest to break and had the least bud damage. However, due to sap flow already in conductive tissues (xylem and phloem) damage in canes and trunks is expected in all species including vinifera. It is difficult to estimate the extent of damage and crop loss now. We know that hybrids usually have the highest crop potential due to fertile secondary and latent buds, but natives and vinifera will have the least crop potential due to low or unfertile secondary buds. Statewide, the damage has occurred mostly in central and southern Ohio, but not in the north. Temperatures in the north were just as cold, but bud development was not as advanced.
 
Few practical suggestions:
 
-  Pruning: With expected cane and trunk damage, practice minimum pruning by hedging or leaving 3 times the amount of buds. Vines heal better their permanent structure by increasing the amount of leaf area early in the spring. Even though vines will be a nightmare to manage with that many buds, but think of 2008 and how to get vines back to production as soon as possible.
 
-  Suckering: plan for the worst and assume you have trunk damage and leave suckers at the base of vines for potential trunk renewal. The other reason for trunk renewal is possible increase in crown gall incidence.
 
- Disaster Assistance: Contact your local USDA-FSA (Farm Service Agency) and report to them your crop loss. It is important that you record the extent of damage you have, in case some assistance program becomes available. The FSA is already assembling crop loss information for the fruit industry in Ohio.
 

Care of Dormant Vines for Replants
By  David Scurlock, HCS-OARDC

Now is the time of the year when your nurseryman is calling and wanting to send out your vines for your new vineyard or your replacement vine order.  What is the proper way to store your vines after you receive them?  Ideally the vines must be stored at 35 degrees Fahrenheit and 50% humidity in a temperature-controlled unit.  When your order arrives, check over the order and make sure that it is correct so there will be no surprises on the day of planting.  If the vines are going to be left in storage for another couple of weeks make sure that the vines are remoistened and wrapped with plastic to keep the buds and roots from drying out.  Check the temperatures of the storage unit weekly to make sure that it is not getting too warm.  If the vines are going to be stored for several weeks, check to see that they remain moist and that the buds are not starting to swell and break.  If you do not have a large enough facility to store the vines, see if your nursery man can hold your order for as long as possible. If you have to rent storage space be careful not to store dormant vines with any ripening fruit.  Ethylene produced by ripening fruit can injure and kill dormant buds.  Dormant vines can be planted any time the soil is fit to work but, remember that May 15 is considered the average frost free date in Ohio.  The coldest temperatures are at ground level and the vines may need to be covered if the threat of frost occurs.  Last year we had freezing temperatures as late as May 23.  Before planting make sure the vines have been thoroughly soaked.  Set them in a tub of water for an hour of rehydration or at least let them soak in a tub of water during the planting process.  Water vines after planting and throughout the growing season if moisture from rain is scarce. Good luck planting!


OSU Viticulture Short Course Announcement
By: Imed Dami, HCS-OARDC
 
 
 
Mark your calendar for this topic-specific short course to be offered on May 22, 2007 at 1 pm - 5:30 pm at the Shisler Conference Center on the OARDC campus in Wooster, Ohio.  The title of the short course is “Recent Advances in Vineyard Site Selection”. The purpose of this short course is to educate new, and existing grape growers, and teachers on the concept of site selection and factors to consider that lead to good decision-making and long-term economic success. New technologies and research advances in the field of site selection used in the Eastern and Midwestern US and that can be applied in Ohio will also be presented in this short course. Topics will cover: macro- and meso-climate considerations for site selection; soil chemical properties and fertility; soil physical properties and water drainage; other crop hazards; matching sites with grape varieties; and the use of GIS and GPS technologies as tools to assist with vineyard site selection. Featured speakers include Dr. Tony Wolf, Viticulturist from Virginia Tech, Dr. Kaan Kurtural, from University of Kentucky, Dr. Larry Brown, Dr. Robert Mullen, and Dr. Imed Dami from the Ohio Sate University.
 
More details and registration information will be sent next week. We hope you can join us at this unique and very comprehensive short course on site selection developed specifically for grape growers.