Editor: Imed Dami, PhD
Assistant Professor, 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/
2 May 2006
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Content:
Frost Damage in OH Vineyards
Dormant Applications on Grapes
Fungicide Spray Program for Wine Grapes
Pesticide Update for the 2006 Season
Growing Degree Days in Ohio
Upcoming Events
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Frost Damage in OH Vineyards
By Dr. Imed Dami, HCS-OARDC
Last Wednesday April 26, several vineyards in the northeastern corner of the
state experienced temperatures below freezing. Several commercial grape
producers, in the Lake Erie Region and south all the way down to Coshocton, have
reported severe damage. Reported temperatures ranged between low to high
twenties, and vine growth stages ranged from bud swell to bud break. Varieties
that sustained the most damage are those with most advanced growth such as many
hybrid and labrusca grapes. Wind machines were turned on between April 26 and 28
and vineyard owners reported that they were effective in reducing the extent of
damage. Other vineyards, however, were not so fortunate even those in good
sites. Some producers have reported that the frost on 26 April was one of the
worst they have experienced in over 20 years.
At the research vineyard in Unit 2, Wooster, we recorded 27.2 F using a
temperature logger placed in the vineyard at 5 feet from the ground. Concord is
our earliest variety in the vineyard and bud break occurred on 24 April which is
about normal for our site. The critical temperature for Concord at the bud break
stage is 27 F. When Frost occurred on 26 April growth was even further advanced
and I estimated 90-100% damage in Concord from my visual assessment. Normally,
temperature below 28 F on April 26 occurs once in ten years in Wooster.
Unfortunately, that happened this year. The median of last occurrence of spring
frost where temperature drops below 32F in Wooster is May 1st.
It is too early to have an accurate assessment of the extent of damage. Greg
Johns, Manager at the Ashtabula Agricultural Research Station in Kingsville and
I have interviewed several producers and more information will be gathered from
juice and wine grape producers in the Lake Erie region. Please contact me or
Greg to report in the following: lowest temperatures on 26-28 April in your
vineyard, the growth stage of varieties when the frost hit, and an estimated
percent of damage. More information will be posted in future O-GEN issues.
Low Temperatures on 26 April at some OARDC Stations in NE-OH.
Weather Station Location
Temperatures (F) on 26 April 2006
Ashtabula Agricultural Research Station, Kingsville
Elevation: 789 ft
26.8
OARDC-Campus, Wooster
Elevation: 1020 ft
24.5
OARDC-Research Vineyard in Unit 2, Wooster
Elevation: 1100 ft.
27.2
Madison Station
USDA Research Station at Sunleaf Nursery
27.6
Here are some facts and tips on spring frost injury:
- Extent of damage depends on the stage of development of buds and
shoots. The more advanced the stage the warmer the critical temperature (or
LT50). For example, LT50 = 24F at first swell, and LT50 = 27 F at bud burst in
Concord. The critical temperature also varies with air relative humidity and
corresponding dew point. Visit
http://web1.msue.msu.edu/fruit/grpfrost.htm to see critical temperatures of
Concord with pictures of different growth stages.
- If leaves are already apparent and they are damaged they first look
water-soaked, oily, and droopy. In a day or two and when it warms up again, the
small shoots turn brown and crispy.
- Swollen buds in a wooly stage are difficult to assess visually.
However, by touching the buds you could feel they’re crispy, crunchy, and
brittle and fall off readily.
- Generally, varieties bear fruit on shoots originated from primary
buds. Some bear fruit from secondary and base buds. Examples include hybrids
such as Seyval, Vidal. Secondary and base buds of Vinifera and Native grapes are
not as fruitful and thus may sustain more crop loss than French Hybrids.
- It is early to make an assessment of the extent of crop loss. The best
way to assess is to wait another month or until the clusters are visible.
Cluster number per vine should give you an idea about percent cluster number
loss. However, this does not mean you would have a reduction in yield.
Grapevines have an amazing ability to compensate for yield.
- Early frost can be advantageous for secondary clusters to develop
larger. Even primary shoots can still develop and produce a crop.
- Last year, we had a great summer with plenty of sunlight and heat.
Those conditions are ideal for high fruitfulness of buds this year. You may be
surprised by a normal crop. Michigan experienced this phenomenon a few years ago
where they had severe spring frost damage and almost looked like it wiped out
the Niagara crop during an assessment in the spring. At harvest, growers
experienced record crop that year.
- If you have any questions regarding this, please contact me at
330-263-3882 (dami.1@osu.edu), or David
Scurlock at 330-2633825 (scurlock.2@osu.edu),
or Greg Johns at 440-224-0273 (johns.1@osu.edu).
Dormant Applications on Grapes: Research Results from Ohio
By Dr. Michael A. Ellis, and Dr. Mizuho Nita, Plant
Pathology-OARDC
Over the past several years, many Ohio growers have asked questions
regarding the use of dormant applications of fungicide for disease control in
grapes. In 2003 through 2005 we conducted several evaluations of dormant
applications of Liquid lime sulfur and fixed copper (copper hydroxide-COCS) for
control of Phomopsis cane and leaf spot on grape. We applied lime sulfur at 10
gallons per acre and copper at 3 lb per acre in 100 gallons of water per acre.
We made applications in the fall (after leaf drop), in the spring at bud swell,
and at both times (spring and fall).
Our results indicate that both lime sulfur and copper applied in the spring
resulted in a significant reduction of Phomopsis leaf and internode infection in
the growing season. Lime sulfur was more effective than copper. There were no
differences in disease control between the spring only and both the spring and
fall applications. Applications in the fall only were not effective. Although
we got a significant level of disease control, we never achieved 100% control of
Phomopsis with the dormant application. Therefore, the dormant application did
not reduce the need for fungicide applications for Phomopsis control during the
season.
For a quick summary of over two years of research, we will make the following
comments:
1. Dormant applications of lime sulfur or copper will provide
some degree of Phomopsis control, but will not reduce the need for the standard
recommended fungicide sprays for Phomopsis control during the growing season.
We have no evidence to indicate that the dormant applications are effective
against any of the other grape diseases.
In short, they could help, but if you have a good spray program during the
growing season, they probably will not result in much of an increase in disease
control at the end of the season. Please remember that this assumes you have a
good fungicide spray program during the season. The bottom line is that if you
have a good spray program and your vineyards are pretty clean, you probably do
not need a dormant application of fungicide in the spring.
We do not recommend a dormant application of fungicide in the fall
for disease control.
2. We do recommend the use of dormant applications of lime
sulfur in the following situations:
A. In organic vineyards, this should be an important spray.
B. In vineyards where Phomopsis is getting out of hand,
this spray should be considered . In some Concord vineyards that are
mechanically pruned, Phomopsis incidence is increasing. A dormant spray of lime
sulfur would probably be beneficial here, but the economics on Concord needs to
be considered.
For wine grape vineyards where the level of Phomopsis infection is severe, the
dormant spray should be considered. A dormant application of lime sulfur in the
spring will aide in disease control, when combined with effective sprays during
the growing season. The economics of the dormant application are questionable.
In other words, the level of control you get may not be worth the cost of the
application. It has been our observation over the past several years that we
can detect some level of Phomopsis in almost every vineyard we inspect. It is
probably not realistic to expect 100% control of Phomopsis on internodes even
with a good full-season spray program ( personal opinion , Mike Ellis). In our
studies, the dormant application of lime sulfur plus a good full season spray
program has never resulted in 100% control of Phomopsis.
C. If anthracnose is present in the vineyard, a dormant
application of lime sulfur at the rate of 10 gallons per acre is very
important. This spray is the major means of controlling anthracnose. We have
seen serious anthracnose in several Ohio vineyards, mainly on Vidal and Reliance
grapes.
In summary, a dormant application of lime sulfur ( lime sulfur appears to be
more effective than copper) in the spring is beneficial for control of Phomopsis
and even necessary in some situations as mentioned above; however, it is not a
“silver bullet” that is going to reduce the need for a full-season fungicide
spray program on wine grapes.
Fungicide Spray Program for Wine Grapes
By Dr. Michael A. Ellis, Plant Pathology-OARDC
The attached information is intended to be “food for thought” in relation to
developing a fungicide spray program for wine grapes in Ohio. The spray
schedule presents various fungicide options that can be considered by growers.
It is important to note that the schedule is intended to provide simultaneous
control of black rot, powdery mildew, downy mildew and Phomopsis cane on leaf
spot. The schedule is also intended to provide fungicide resistance management,
primarily against the powdery mildew fungus. Note that there are usually
several fungicide options that can be selected. This schedule does not contain
all of the fungicides currently registered for use on grapes. Remember, these
are only “Suggested Guidelines” for use in developing a fungicide
program. The final program that you develop will depend upon the disease
complex in your vineyard as well as economic considerations.
Pesticide Update for the 2006 Season
By Dr. Roger Williams and Dan Fickle,
Entomology-OARDC
Spring has arrived and its time to take note of your pesticide needs for
this season. With this in mind we want to keep you informed of some new
products that have recently obtained a grape label.
Venom (dinotefuran), (Valent USA)
This is a third generation neonicotinoid which provides excellent control of
sucking insects, such as leafhoppers, aphids and mealybugs. It has demonstrated
good efficacy for up to 4 days post treatment against the Multicolored Asian
lady beetle (MALB). The harvest restriction interval for foliar application is
only 1 day so we believe it will be a valuable tool in controlling late season
MALB infestations. Take note that this product is listed on page 49 of
the 2006 Midwest Commercial Small Fruit and Grape Spray Guide as having a 52 day
harvest restriction on grapes. This is a typo and should read 1 day when applied
as a foliar application and 28 days if applied as a soil drench.
Baythroid (cyfluthrin), (Bayer Crop Science)
This is a new pyrethroid similar to Capture and Danitol. It’s labeled for
control of flea beetle, grape berry moth, leafhoppers, cutworms, grape leaf
skeletonizer, and glassy winged sharpshooter. We tested this product over a
decade ago and found it to also provide good control of Japanese beetle and
foliar phylloxera. Additional studies in the laboratory this winter have
demonstrated good efficacy against the MALB. One very important aspect of this
new product is that it has only a 3-day harvest restriction. This is the first
labeled pyrethroid with a short harvest interval making it a good candidate for
late season control of MALB and grape berry moth. This product is not listed
in your 2006 spray guide so look to the product label for recommended rates.
Guthion (azinphosmethyl), (Bayer Crop Science)
This product is no longer labeled for grapes. If you still have old product you
may continue to use it up.
Pheromone traps.
Pheromone is available for determining the presence of grape berry moth, rose
chafer and grape root borer.
Just a couple of grape berry moth traps placed in the vineyard can help you
determine when adults are present and help in timing control sprays. However,
you should not use them as an indicator of the berry moth population. Remember
that pyrethroids are highly effective against grape berry moth but do not have a
long residual effect, 7 to 10 days at best if little rain fall is encountered.
Grape root borer is a difficult pest to detect or control since it spends the
majority of its time in the plants root system. We do however; have an
extremely good pheromone for determining the presence of this pest within a
vineyard. Many of you are new growers and may not be familiar with this pest.
It is mainly a problem in the southern part of our state but has shown signs of
moving northward over the past decade. If you would like to monitor your
vineyard for this pest we do have pheromone available in our lab and would be
glad to provide you with some lures. Just give us a call or email us and we
will see that you get some for the upcoming season.
If you have any questions concerning pest management, please contact us at,
fickle.1@osu.edu , phone 330-263-3623 or
williams.14@osu.edu , phone
330-263-3731 We would like to thank all of you for your support and hope you
have a prosperous season.
Growing Degree Days in Ohio
(Source: Ohio Fruit ICM News; Editor: Dr.Shawn R.
Wright)
Data through April 30 from OSU Phenology Garden Network (not all locations)
OSU Phenology Garden Network. GDD
(growing degree days) modified sine wave method. Form more information on the
calculation of GDD check this site
http://www.oardc.ohio-state.edu/gdd/glossary.htm
OSU South Centers Piketon
434
Athens 405
Chillicothe 400
Marietta 393
Wilmington 357
Columbus & Washington CH
345
Newark 335
Delaware 329
Xenia 320
Mt. Sterling 318
Coshocton 315
Wooster 288
Mansfield 285
Canton 283
Findlay
257
Canfield 249
Toledo
248
Norwalk 243
Stow 242
Shinrock 234
Cortland 214
Willoughby 208
Kingsville 188
2006 Upcoming Events
May
8-10 Pennsylvania Wine Association Annual Meeting.
Wyndham Hotel Harrisburg/Hershey. Harrisburg, PA. Invited speakers focus on
current topics important to the PA wine industry. Enology, wine marketing and
viticulture topics are all on the program. Pesticide credits available. Awards
banquet and annual PWA business meeting. For information, please call Jennifer
at 717-234-1844.
June
7 Maryland Grape Growers’ Association Field Day. Upper Marlboro UMD
Center. Visit the MGGA web site for details.
www.marylandwine.com/mgga/
28-30 American Society for Enology and Viticulture Annual Convention.
Sacramento, CA. ASEV is the professional association of the U.S. wine
industry. The focus is on viticulture and enology research with a large trade
show. For more information, go to www.asev.org.
July
9-12 American Society for Enology and Viticulture Eastern Section Annual
Meeting. Rochester, NY. This is an important opportunity for non-western states
growers to hear the latest research results from their regions include student
papers and Viticulture Consortium projects. Pre-conference tour of Finger Lakes
wineries is available. For more information, visit the ASEV-ES web site at
http://www.nysaes.cornell.edu/fst/asev/