January, 2000
News Items:
Extension Viticulturist Search
Ohio Grape-Wine Short Course
Effects of Root Pruning Grapevines
New Fungicides for Grape Disease Control
Upcoming Events
Please visit our web site at: http://www.oardc.ohio-state.edu/grape
EXTENSION VITICULTURIST SEARCH
After Maurus left, we conducted a broad national search for a replacement and formed a search committee of Marlene Boas, Mike Ellis, Nick Ferrante, Dave Ferree, Diane Miller and Joe Scheerens. There were 7 applicants for the position and three were invited for an interview. After long deliberation, the committee decided not to offer the position at this time and conduct another search in late summer or early fall.
We want to solicit input on the type of person and skills you would like to see in our extension viticulturist. Please pass them on to any member of the committee.
OHIO GRAPE-WINE SHORT COURSE
February 13-15, 2000 Wyndham Dublin Hotel, Dublin Ohio
We are excited about the program for Short Course this year and hope it contains subjects that will offer information for beginners and those with long experience. Registration forms are available from OWPA, PO Box 157, Austinburg, OH 44010 (phone 1-800-277-6972).
In addition to the entire educational program shown below, the short course offers a chance to discuss mutual problems with others in the industry as well as direct contact with people who support our industry at the trade show. Often information picked up in those discussions will save you more than the cost of attending.
2000 SHORT COURSE PROGRAM
SUNDAY, February 13
Presiding: Mary Jo Ferrante
10-12:30 Basics of Establishing a Winery/Vineyard Industry Panel
1:00-1:30 Phenolics and Tannins in Grapes and Wine-- Leslie Weston
Their Roles in Oak, Flavor and Health
1:30-2:00 Air, Water, Sun and Fire--The Cooper's Henry Work
Wooden Footprint
2:00-2:30 Tasting I: Chardonnay, Firelands Winery
Objectives: 1. Evaluate the effect of oak origin on wine quality and style
2. Evaluate the effect of cooper on barrel quality and style
3. Evaluate the effect of toast level on wine quality and style
2:30-3:00 Tasting II: Chardonnay, Ferrante Winery
Objective: Evaluate the effect of oak origin on wine quality and style
3:00-3:30 Tasting III: Chardonnay, Ferrante Winery
Objectives: 1. Evaluate the effect of oak chips on wine quality and style
2. Evaluate the difference between chips and barrels
3. Evaluate the source of oak chips on wine quality and style
3:30-4:00 Break
4:00-4:39 Keeping the Bugs Unhappy--Successful Barrel Henry Work
Sanitation and Maintenance
4:30-5:00 Chip Me, Stave Me, Oak Me--The Romance, Tim DiPlacido
Dollars and Sense of Barrel Alternatives
5:00-5:30 Tasting IV: Pinot Gris, Chalet Debonne Vineyards
Objectives: 1. Evaluate the effect of the cooper on barrel quality and style
2. Evaluate the effect of lees stirring on wine quality and style
5:30-6:00 Tasting V: Pinot Gris, Chalet Debonne Vineyards
Objectives: 1. Evaluate the effect of oak chips on wine quality and style
2. Evaluate the difference between chips and barrels
6:00-7:30 OWPA Membership Meeting
7:30-9:30 Vidal OpenHouse
MONDAY, February 14
Presiding: Ed Heineman
8:00- 8:10 Introduction & Welcome Stephen Myers
8:10- 8:30 Report on Cool Climate Symposium Roland Riesen
8:30- 9:00 Future of Burgundy Wines in A Global Pascal Durand
Wine Market
9:00- 9:45 Developing New Rootstocks Andrew Walker
9:45-10:15 Partnering For Profit Donnie Winchell
10:15-10:30 Break
10:30-11:00 Assessing Grape Maturity by Taste & Numbers Thomas Henick-Kling
11:00-11:20 Influence of Fruit Condition on Wine Quality James Gallander
11:20-11:40 Influence of Post Bottling Storage Temperature Todd Steiner
on Wine Quality
11:40-12:40 What We Do At Harvest To Help Wine Quality Tony Debevc
Nick Ferrante
Greg Pollman
Influence of Post Bottling Storage Claudio Salvador
12:40- 1:45 Lunch
Presiding: Lee Klingshirn
2:00- 2:45 Matching Rootstocks and Soils Andrew Walker
2:45- 3:15 Pinot Noir Production in Burgundy Pascal Durand
3:15- 3:45 Challenges Associated With Pinot Noir Leslie Weston
Production in the Finger Lakes
3:45- 4:15 Review of New York Experience with Thomas Henick-Kling
New Wine Grape Cultivars
4:15- 4:30 Break
4:30- 4:50 Securing Harvest Labor Thomas Sachs
4:50- 5:05 A Unique Approach to Harvest Labor Fran Massaro
5:05- 5:30 Disease Control with New Fungicides Mike Ellis
7:00- 8:00 Reception - Ohio Award-Winning Wines
8:00 Banquet
TUESDAY, February 15
7:00 Growers Breakfast
Presiding: Art Pietrzyk
8:30- 9:00 Recent Developments in Understanding Phomopsis Mike Ellis
9:00- 10:00 Rootstock Performance in Ohio Arnie Esterer
Gene Sigel
Ron Barrett
Roland Riesen
10:00-10:15 Break
10:15-10:30 Pesticide Update Doug Doohan
Mike Ellis
Roger Williams
10:30-10:55 Weed Control in Vineyards Doug Doohan
10:55-11:15 Light and Fruit Set Dave Ferree
11:15-11:45 Does Compost Have a Place in Ohio Vineyards Harry Hoitink
11:45-12:05 Control Strategies for Soil Insects in Vineyards Roger Williams
EFFECTS OF ROOT PRUNING GRAPEVINES
D. Ferree, D. Scurlock, G. Johns and R. Riesen
Mature grapevines were mechanically root pruned to a depth of 15 inches on two sides, 15-20 inches from vines. Root pruning 'Sevyal blanc' and 'Catawba' at bloom and/or veraison for three years had little effect on the various components of yield or juice composition. Pruning time of 'Catawba' was reduced by root pruning. Root pruning vigorous 'Concord' vines at bloom for four years resulted in a reduction in pruning weight and pruning time in one year. Yield/vine was reduced by root pruning two of the four years and the reduction was due to a reduction in cluster weight. Increasing levels of soil applied nitrogen to a maximum of 120 lbs N/acre had no effect on growth or cropping of 'Concord'. Root pruning was not successful in controlling vegetative growth or improving juice composition of grapes.
The general lack of influence of root pruning on grapevines was unexpected, since rather consistent reduction in growth occurred with apple trees and other plants. In a previous exploratory trial in a commercial Ohio vineyard, shoot length of 'Seyval blanc' and 'White Riesling' was reduced by root pruning, while growth of 'Delaware' was unaffected. Although grapevine response to root pruning may differ due to cultivar, the present study showed no effect of vigorous cultivars ('Catawba' and 'Concord') and a weak growing cultivar ('Seyval blanc'). It is interesting that growth of 'Seyval blanc' was not further weakened by root pruning. This may have been due to stimulation of new root growth close to the cut made by the pruner. Van Zyl and Huyssteen have recommended root pruning to stimulate growth of vines in severely compacted soils in South Africa.
Studies with potted grapevines show that growth of grapevines can be reduced by root
pruning and generally the greater the degree of pruning, the greater the reduction in
growth. Grapevines were less responsive to root pruning that apple requiring a greater
amount of root removal to get a similar reduction in growth. This may partially explain
the lack of response in the present study, since the equipment prevented getting closer to
the vine than 15-20" on each side. During root pruning the initial year vines would
tremor as the machine passed and 1/2" diameter and larger roots were observed being
cut. In subsequent years small severed roots accumulated on the shank; however, the
quantity of roots removed was not quantified by excavation.
The primary reason to root prune 'Seyval blanc' and 'Catawba' in these studies was to see
if juice composition could be altered to improve wine quality. Previous work with apple
resulted in reduced fruit size and increased soluble solids. Smaller grape berry size has
been reported to increase the skin to pulp ratios and improve the aroma and flavoring
constituents of juice for wine. Berry size or juice composition was not altered by root
pruning in these studies.
In the 'Concord' study it was postulated that root pruning would help control the increased growth induced by adding nitrogen to increase cropping. The effects of root pruning on growth were minimal and there was no interaction of root pruning and soil applied nitrogen for any of the parameters measured. Petiole N concentration was within the .9 to 1.3% sufficient range for all treatments even the control that received no N for four years. The lack of response to N applied to this fertile soil has also occurred in other studies of perennial crops. Root pruning would not be recommended for 'Concord' due to the reduction in yield.
In summary, root pruning grapes in the field was not successful in improving juice composition or controlling growth. The lack of response may have been due to the limitations of the equipment not being able to get close enough to the vine trunk to cut enough roots to induce a response. The variability in trunk straightness is also a concern in modifying equipment to see how close would be necessary to consistently influence vegetative growth.
PLANT DISEASE NOTES
Mike Ellis
New Fungicide Registrations for Grape Disease Control
Sovran 50WG fungicide was recently registered for use on grapes for control of Phomopsis cane and leaf spot, black rot, powdery mildew, and downy mildew. Sovran is a product of BASF Corp. and is the second fungicide in the new class of chemistry (Strobilurin) to be registered for use on grapes in the U.S. Abound was the first Strobilurin to be registered, and most Ohio growers are familiar with Abound. Sovran is similar to Abound in that it provides good control for most of our major grape diseases. Unlike Abound, Sovran is not phytotoxic (damaging) to McIntosh apples and other related apple varieties. Although Sovran and Abound are closely related and both are excellent fungicides, they do differ in their effectiveness against certain diseases. Both Abound and Sovran provide very good control of black rot with about equal efficacy. Both fungicides are also very effective against powdery mildew; however, Sovran appears to be more effective than Abound against powdery mildew. The biggest difference is with downy mildew. Abound is much better for control of downy mildew than Sovran. Sovran will provide good control of downy if the highest label rate is used (5.6 oz/A). Sovran is registered for use at 3.2 to 4 oz/A for black rot, 3.2 to 4.8 oz/A for powdery mildew, and 4.0 to 5.6 oz/A for downy mildew. The 4 oz/A rate has provided good control of black rot and powdery mildew in fungicide trials. Obviously, the rate of 5.6 oz/A for control of downy mildew will greatly increase cost. Abound is registered for use at 11 to 15.4 fluid oz/A. In the last couple of years, ohio growers have used Abound at the rate of 11 to 12 fluid oz/A with good results.
Flint 5OWG fungicide was also registered for use on grapes late in 1999. Like Abound and Sovran, Flint is also a strobilurin fungicide. The use of Flint on grapes in Ohio will probably be very limited due to following factors:
For these reasons, Ohio growers will probably select either Abound or Sovran as the strobilurin fungicide of choice for use on grapes. Cost and the various "special" characteristics of each fungicide will determine which is used. The important thing to note is that these are excellent fungicides and should be incorporated into our fungicide spray program for grapes in Ohio.
I have reason to believe that the labels for all the strobilurin fungicides will be changed to permit no more than 4 applications of any strobilurin fungicide per growing season. This measure is intended to aid in the development of fungicide resistance to the Strobilurin fungicides.
Both Sovran and Abound have a 14 day PHI and; therefore, can be used late in the growing season for control of downy and powdery mildew if needed.
Note: The strobilurin fungicides (Abound, Sovran and Flint) are not very effective for control of Phomopsis cane and leaf spot.
Elevate 50WDG fungicide was registered for control of Botrytis bunch rot on grapes in 1999. Elevate is a product of Tomen Agro, Inc. and has good activity against Botrytis. Elevate is different chemistry than Vangard, Rovral, and Benlate. With the addition of Elevate, grape growers have a good arsenal of fungicides available for control of Botrytis bunch rot.
Vangard Fungicide (Cyprodonil) and Elevate fungicide (Fenhexamid) are both registered for control of Botrytis bunch rot. These are welcome newcomers to our arsenal of fungicides for Botrytis control, which is actually very sparse. At present, Rovral, Benlate, Vangard, and Elevate are the fungicides recommended for bunch rot control. Many growers no longer use Benlate due to the development of fungicide resistance. Rovral has been the "Cadillac" fungicide for Botrytis control, but concerns over fungicide resistance development also exist with Rovral. This makes the registration of these new fungicide chemistries (Vangard and Elevate) especially important. Where resistance is not a problem with Rovral, the efficiency of Vangard and Elevate is similar to that of Rovral. Vangard and Elevate are both good Botrytis materials. However, in several fungicide trials, Vangard appears to be more efficacious than Elevate.
All of these materials are costly and should be used correctly and only on the tight-clustered "more valuable" wine grapes. Especially where Rovral has been used for many years, or where the efficacy of Rovral for Botrytis control appears to be reduced, these new materials should be introduced into the fungicide program for Botrytis control.
Developing an effective Fungicide Spray Program for Wine Grapes.
The following information is intended to be "food for thought" in relation of our fungicide spray program for wine grapes. I hope it will be useful, especially to new growers that are currently developing or modifying a fungicide program for grapes in Ohio.
Remember: If you have questions about fungicides, or any aspect of grape disease control, contact Mike Ellis. Phone: 330-263-3849. Email is: ellis.7@osu.edu.
SUGGESTED OPTIONS FOR A FUNGICIDE
SPRAY PROGRAM
FOR WINE GRAPES IN OHIO
This program is intended to provide simultaneous control of Block Rot, Powdery Mildew, Downy Mildew and Phomopsis Cane and Leaf Spot
1 inch shoot Mancozeb 3 lb/A
NOTE: Mancozeb alone for Phomopsis only. If Powdery Mildew is a concern this early in the growing season, use:
Mancozeb 3 lb/A
PLUS
Rubigan 3 fl oz/A
Or
Sulfur 6F 4 qt/A
Or
Wettable Sulfur 8-10 lb/A
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3-5 inch shoot Mancozeb 3 lb/A
or 10 days later PLUS
Rubigan 3 fl oz/A
Or
Sulfur 6F 4 qt/A
Or
Wettable Sulfur 8-10 lb/A
NOTE: If Powdery Mildew is a major concern, Rubigan is the fungicide of choice to combine with Mancozeb. Also, be aware that the efficacy of Sulfur for Powdery Mildew control declines below 65F. If cool temperatures persist (below 65F), Rubigan should be used instead of Sulfur for Powdery Mildew. On Sulfur sensitive varieties, use Rubigan. If Powdery Mildew is not a problem, Mancozeb alone can be used.
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10-12 inch shoot Same fungicides
or 10 days later as 3-5 inch shoot
------------------------------------------------------------------------------------------------------------------Immediate prebloom Abound 11-12 fl oz/A
or 10 days later (Strobilurin fungicide)
------------------------------------------------------------------------------------------------------------------
First postbloom spray Abound 11-12 fl oz/A
no longer than 10-14 days later (Strobilurin fungicide)
------------------------------------------------------------------------------------------------------------------
Second postbloom spray Mancozeb 4 lb/A
no later than 10-14 days later PLUS
Rubigan 6 fl oz/A
Or
Sulfur 6F 4 qt/A
Or
Wettable Sulfur 8-10 lb/A
NOTE: In order to prevent the development of fungicide resistance, Rubigan should not be used more than 3 or 4 times (preferably 2-3 times) per season.
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Summer Sprays Should Not Exceed a 14-Day Interval
Third post bloom spray Abound used alone 11-12 fl oz/A
10-14 days later (Strobilurin fungicide)
Or
Mancozeb 3-4 lb/A
PLUS
Sulfur 6F 4 qt/A
Or
Wettable Sulfur 8-10 lb/A
NOTE: Rubigan or another sterol inhibitor fungicide can be used postbloom for Powdery Mildew control; however, season long use of the sterol inhibitors will greatly increase the risk of fungicide resistance development. Especially if early season disease control is good, emphasis for Powdery Mildew control later in the season should be placed on Sulfur, a Strobilurin fungicide (Abound or Sovran),a fixed copper fungicide or JMS-stylet oil.
NOTE: Watch the 66 days PHI on Mancozeb. If you get within 66 days of Harvest, Captan can be used in place of Mancozeb. The danger of black rot infection should be over by this time. Berries should be resistant to black rot. The Mancozeb or Captan is included for Downy Mildew control.
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Fourth post bloom spray Abound used alone 11-12 fl oz/A
10-14 days later (Strobilurin fungicide)
These fungicide choices Or
will be used through Mancozeb (watch 66 day PHI) 4 lb/A
harvest Or
Captan 50w 4 lb/A
PLUS
Sulfur 6F 4 qt/A
Or
Wettable Sulfur 8-10 lb/A
Or
Fixed Copper Fungicide used alone
NOTE: If dry weather persists and the risk of Downy Mildew is low, Mancozeb or Captan should not be required and Sulfur can be used alone. If weather is wet and Downy is a problem, a Downy Mildew material needs to be included. A Fixed Copper Fungicide will give good control of both Downy and Powdery Mildew.
______________________________________________________________________
NOTE: For Botrytis bunch rot control, the following fungicides are available:
Rovral 1.5 lb/A
PLUS
Latron B1956 6 fl oz/100 gal
Or
Vangard 10 oz/A
Or
Elevate 1 lb/A
This will be used only on bunch rot prone cultivars. The first spray will be made when disease is first observed or at veraison (or shortly thereafter). Then wait until a combination of threatening weather and/or disease develops and make a second spray (at least 2 weeks after the first spray). On late maturing varieties a third spray may be required.
______________________________________________________________________
NOTE: Sovran is a Strobilurin fungicide similar to Abound in activity. It can be used in place of Abound in this spray program. Sovran is not as effective as Abound against Downy Mildew.
NOTE: New labeling will probably restrict the application of the Strobilurin fungicides (Abound and Sovran) to a maximum of 4 applications per season.
Upcoming Events:
Viticulture 2000 February 18 and 19, 2000 Adams Mark Hotel, Buffalo, NY
Tim Martinson, Finger Lakes Grape Program,
110 Court St., Penn Yan, NY 14527 (315)536-5134
This meeting has an excellent program covering many topics on vineyard management as well as marketing and business management. A distinguished list of featured speakers including Richard Smart from Australia, several from Canada, as well as several from California, Michigan, Arkansas, plus a broad group from New York. We have a limited number of full programs and application materials. Contact: Dave Scurlock, Hort and Crop Science, OARDC, 330-263-3825 or 330-263-3878.
Heartland Wine School June 5-7, 2000 Wyndham Dublin Hotel., North Dublin, OH
This school is jointly sponsored by Purdue University, Michigan State University and Ohio State University and follows a series of successful schools. The school is designed for commercial winemakers to teach advanced practical wine science and production techniques. A detailed program will be available in March, but please reserve these dates. Additional details available from Dr. Roland Riesen, OARDC, 330-263-3814.