IPM Master Presentation

+

The New Minnesota Grape Integrated Pest Management Manual: Pathogen Fact SheetsJoy A HiltonMaster of Agriculture in Horticultural Science

+Personal Goals Personal Career Goals

Work with vineyard owners to help them create sustainable and/or organic vineyards.

Own and operate a vineyard and winery.

Personal Project Goals Gain a thorough understanding of the following

Grape disease cycles, signs and symptoms Economic impacts Resistant and susceptible cultivars Conventional and organic sprays Cultural control practices

Identify diseases in the field

This project, along with other courses, will assist me in working in the field of sustainable viticulture.

+IPM Manual Goal

Create a one stop shop for Minnesota grape growers.

Provide an overview of sustainable grape production.

Cover common pests and pathogens as well as general IPM practices specific to Minnesota grape growing.

+Need for a MN Grape IPM Manual

Funding provided by the Department of Agriculture.

Increasing grape grower population.

Based on the Minnesota Grape Growers Profile, 2007.

Need for Minnesota Specific information. Our climate and varieties require different practices.

+MN Grape Grower Profile

There are a total of 632 vineyards in Minnesota.

65% were planted within the last five years.

Estimated total number of acres in Minnesota is 1,056

Estimated 582,072 vines in Minnesota.

+Grape Use - MN Grape Grower Profile

Growing for many purposes.

Many new growers are not professionals. View grape growing as a good

way to earn extra income. Fun retirement plan for

someone who loves grapes and does not really want to retire.

+Deciding what to cover

Fall of 2007, Dr. Hoover created a survey that was handed out to local growers at the September Grape Growers Association meeting held at the Horticulture Research Center (HRC).

Interviewed MN growers and Peter Hemstad, owner of St. Croix Vineyards and research scientist at the Horticulture Research Center.

+Available resources

Various resources available, but in many locations and not user friendly. Ohio State’s Midwest Small Fruit Pest Management Handbooks

Aimed at more experienced growers, covers a broad spectrum of small fruits and does not address many cultural practices or organic methods of control in detail.

The Compendium of Grape Diseases, by Pearson and Goheen Geared toward plant pathologists rather than growers.

From Vines to Wines by Jeff Cox General understanding of grape growing, but not enough disease information to assist

growers with real issues.

The Backyard Vintner by Jim Law Helpful with training techniques and producing small batches of wine, but does not go

into enough disease detail for larger scale production

General Viticulture by Winkler, Cook, Kliewer, and Lider Helpful, but must be cross referenced with up to date (post 1979) and cold climate

information.

It is difficult for new growers to decipher what is best for their vineyards in a quick or easy manner.

+Process

Manual work distribution Dr. Hoover - general IPM sections Joy Hilton – Pathogen Factsheets Suzanne Wold-Burkness – Pest Factsheets Dimtre Mollov – Viral Factsheets

Scouted vineyards for disease symptoms.

Gathered Resources

Wrote factsheets

Reviewed by Dimtre Mollov

Reviewed by Dr. Hoover

Rewrites as needed

+Web Overview

+Web Examples

+Diagnostic Web Page

+Sustainable Grape Growing

Integrated pest management (IPM) is a philosophy based on several guiding principles. Control options that are environmentally sound, socially acceptable

and economically feasible.

IPM is built on information about both the crop and the pest. Crop

Production practices, soil type and pH, and at what growth stages is the plant susceptible to a particular pest infestation.

Pest When the pest is present in relation to the susceptible growth stage of the

crop, what stage of the pest is most easily managed, and what pest level causes economic loss.

+Pathogen Factsheet Format

Overview of disease

Symptoms Vegetative Fruit

Disease Cycle To help the grower understand when treatment will be affective.

Control Strategies Cultural Practices

What, when and why.

Cover traditional and organic treatments. Referred to alternative chemical site.

References For growers to do more in-depth reading if desired.

+Black Rot - Overview

Native to North America

Can cause significant crop damage in Minnesota

Most Minnesota hardy varieties are highly resistant Frontenac, Frontenac Gris and Marquette, V. vinifera are highly susceptible.

In warm humid climates, susceptible varieties can experience complete loss if the pathogen is left uncontrolled.

+Black Rot – Vegetative Symptoms

Young leaves are susceptible to infection as they unfold. Become resistant once they mature.

Small, tan, circular spots appear in spring and early summer. About two weeks after the initial

infection.

Within a few days small black fruiting bodies develop around the necrotic area.

http://ohioline.osu.edu/b919/0010.html

http://www.ppdl.purdue.edu/PPDL/weeklypics/Weekly_Picture6-25-01-2.html

+Black Rot – Fruit Symptoms

Berry infection is the most serious phase. Possibly leads to significant economic losses.

Susceptible to infection immediately prior to bloom through four weeks after bloom. Small, whitish dot that is quickly surrounded

by a reddish, brown ring. The berries will dry out, loosing their

spherical shape and becoming flat on the top.

Appear light or chocolate brown and quickly develop black spores on the surface

+Black Rot – Disease Cycle

Overwinters in mummies on the vineyard floor or vine.

In the spring, with a rain of 0.3mm, ascospores and conidia are released and dispersed by wind and water.

This process can continue for up to eight hours after one rainfall.


+Black Rot – Control Strategies

Sanitation Clear all mummies from the ground after leaf drop or till

them into the soil prior to bud break.

Utilize pruning and training systems to improve air circulation.

Choose resistant cultivars, such as Frontenac and Frontenac gris.

Spray Timing Monitoring and spraying should begin immediately

before bloom through four weeks after bloom.

Organic Sprays Fixed copper or sulfur products.


+Downy Mildew - Overview

Downy mildew is a major disease of grapes in Minnesota.

Causes deformed shoots, tendrils and clusters as well as premature defoliation.

A major outbreak of this disease can cause severe losses in yield and quality.

In the Midwest, symptoms don’t usually appear before bloom.

+Downy Mildew – Vegetative Symptoms

Develop yellowish-green lesions on the upper surface.

Affected area becomes brown, or necrotic, and is limited by veins.

Fungal sporulation occurs on the lower leaf surface in the form of a delicate, dense, white growth. This downy growth is what gives the disease

its name.

Young shoots, tendrils, petioles and inflorescences are also infected.

+Downy Mildew – Fruit Symptoms

Young berries are highly susceptible to downy mildew infection.

Appear grayish in color and are covered in a downy felt.

Becomes resistant to infection three to four weeks after bloom

Berries will remain in the cluster and are easily distinguished from healthy ripening berries.


+Downy Mildew – Disease Cycle

Overwinters on leaf debris as oospores.

In spring germinate in water when the temperature reaches 52oF.

Treelike structures, emerge from the stomata of plant tissue. This growth requires 95-100%

humidity, four hours of darkness and a temperature of 64-72oF.

The sporangia are then dispersed by wind or rain/water splash to the stomata of plant tissue.


+Downy Mildew – Control Strategies

Humidity Choose a site where vines are exposed to sun all day

through the growing period. Utilize pruning and training systems to improve air

circulation. Proper weed control.

Sanitation Clear crop debris from the ground after leaf drop or

incorporate it into the soil at the beginning of the season.

Choose resistant cultivars, such as Frontenac, Frontenac Gris, Marquette or Marechal Foch.

+Downy Mildew- Control Strategies

Spray - Timing Monitor V. vinifera all season. Monitor other varieties just prior to bloom through

fourteen days after bloom. Organic

Copper hydroxide and copper sulphate. Only protects vines from new infections. Does not eliminate existing infections and are not

systemic. Use of copper in organic agriculture is of

environmental concern. Alternatives include plant extracts, biological controls and

substances that trigger the vines’ immune system. Have not proven to be economically viable in

controlling downy mildew.

+Eutypa Dieback - Overview

One of the most destructive woody tissue diseases found in commercial grape production.

For many years, phomopsis was thought to be the cause of dead-arm disease.

Researchers discovered, in 1976, that this disease was caused by phomopsis, which causes the spotting phase of the disease, and eutypa dieback.

Symptoms The symptoms seen in vines over six years old. Younger vines can be infected but will not exhibit

symptoms for two to four years.

+Eutypa Dieback – Vegetative Symptoms

The most obvious signs appear in the spring when healthy shoots are 12-24 inches long. Shoots will appear deformed and discolored. Young leaves will appear smaller, cupped and

chlorotic. They may develop small necrotic spots and

tattered margins. Not obvious later in the growing season. Leaf symptoms become more pronounced each

year until the infect portion of the vine dies. http://ohioline.osu.edu/b919/0010.html

+Eutypa Dieback - Symptoms

The earliest symptom is a canker that develops around old pruning wounds on the older wood of the main trunk. A flattened area may be observed on the trunk indicating

the canker under the bark. Removing the bark reveals a defined discolored area of

wood bordered by white, healthy wood.

Fruit The fruit of infected vines do not exhibit many symptoms. Clusters on infected shoots may have a mixture of small

and large berries.


+Eutypa Dieback - Disease Cycle

Survives over many years in the trunks of infected living vines and dead grape wood.

When free water is available, in early spring, spores are released.

Germinates within 11-12 hours when the temperature reaches 68-77oF.

Symptoms develop after several growing seasons.

+Eutypa Dieback - Control Strategies

Pruning Due to the pathogen viability it is important to prune

during dormant season. Prune below the canker or discolored wood.

If the canker extends below the soil line, the entire vine should be removed to ensure removal of the pathogen.

There are not currently any eutypa dieback specific fungicides, organic or conventional, available on the market.

+Grape Phomopsis cane and leaf spot - Overview

A growing disease in the Midwest.

In some states 30% crop loss has been reported in one growing season.

Most crop loss is due to infection of the rachis and the berry.

+Grape Phomopsis cane and leaf spot – Vegetative Symptoms Shoot

Chlorotic spots with dark centers spread over infected tissue.

May make the shoots susceptible to wind damage, but they do not directly cause crop loss.

Extremely important source of inoculum for cluster and fruit infections in the spring.

Leaf Small, light green or chlorotic spots with dark

green centers. Puckered along the veins.

Dark brown spots can also appear along primary or secondary veins and petioles.



+Grape Phomopsis cane and leaf spot – Fruit Symptoms

Most susceptible in early spring.

Green fruits appear normal with the pathogen remaining latent.

At ripening the pathogen becomes active causing the fruit to rot.

Turns light brown and shrivels, resembling black rot infected fruit.

http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=515.00000

+Grape Phomopsis cane and leaf spot - Disease Cycle

Overwinters on infected wood between one and three years old.

Spores washed or splashed to developing shoot tips. Germinate when temperatures are between 34-90oF. Infection takes place within a few hours. Symptoms appear within 21-30 days.

If there are successive cool, wet springs, the inoculum will build up.

Pathogen tends to spread within a vine, not from vine to vine.

Spread of phomopsis is normally caused by transportation of infected or contaminated propagation materials or nursery stock.

+Grape Phomopsis cane and leaf spot - Control Strategies Aeration

Pick a vineyard location with good air circulation. Use appropriate pruning and training systems.

Prune out and destroy any diseased parts from the vines or vineyard floor, during dormant season.

Burn, bury or disc infected plant material.

Spray Spring foliar applications if rainfall is predicted after budbreak. Sprays should be applied before the first rain after budbreak, before shoot

length reaches 0.5 inches and again when shoots reach 5 inches in length.

Contact materials, such as copper or sulfur, may need to be reapplied after significant rainfall

Currently no specific fungicides approved for organic growing.

+Powdery Mildew - Overview

Powdery Mildew is an important disease of grapes in Minnesota.

Can reduce vine growth and yield.

Affects fruit quality and winter hardiness.

Symptoms Left untreated on the berry it can destroy entire

clusters. Foliar infections can reduce photosynthesis causing

reduced Brix levels and vine growth.

+Powdery Mildew – Vegetative Symptoms

Leaf White or grayish-white patches on the upper and lower

surface of leaf, spread to cover upper surface. Uninfected cells, next to infection sites, may become

necrotic. Leaves may dry out and prematurely drop. When young leaves are infected they will become

distorted and stunted as they expand.

Shoots & Stems Young, infected shoots develop dark brown lesions that

remain as brown patches on the dormant stems. Petioles and cluster stems become brittle and break during

the growing season.


+Powdery Mildew – Fruit Symptoms Flower

Blossom clusters can become infected causing flowers to drop.

Berry Highest level of economic loss. Small spots, similar to the leaves. Covered by the white, powdery growth. Can kill the epidermal cells of the berry.

Splitting opens the fruit to secondary bunch rot infections.

May develop a netlike pattern of scar tissue over the surface.

Berries are susceptible to infections from bloom through a few weeks after bloom.

http://sdgrapes.sdstate.edu/grapesd.cfm

+Powdery Mildew - Disease Cycle

Overwinters in bark crevices on the grape vine.

In the spring airborne spores are discharged. With an average of 0.10 inch of rain and an air

temperature of 50oF within 4-8 hours. Carried by wind to any green surface of the growing

vine.

The first infections are often observed as individual colonies growing on leaves closest to the bark.

Need high relative humidity, 40%-100%, rather than free rain to spread infection.

+Powdery Mildew - Control Strategies General control practices

Site selection Pruning Vineyard Sanitation

Timing Monitor susceptible cultivars, particularly V. vinifera cultivars, regularly. Start monitoring just prior to bloom through fourteen days after bloom. Late season monitoring should be done when heavy dew or foggy weather is

prevalent.

Organic Sulfur products starting at budbreak. They need to be applied every seven days or reapplied whenever they are

washed off by rain or irrigation. There are various oils, biofungicides and soaps used to control powdery mildew.

+Botrytis Bunch Rot - Overview

Common problem for most small fruit growers in Minnesota.

Grape cultivars commonly grown in Minnesota tend to show resistance.

The greatest losses found in tight-clustered varieties of V. vinifera and French Hybrids.

Known as both vulgar rot and noble.

http://bigblondeblog.blogspot.com/2006/05/history-of-alcohol.html

+Botrytis Bunch Rot – Vegetative Symptoms

The first symptoms observed in early spring on buds and young shoots. May turn brown and dry out. Before bloom, leaves may exhibit large,

irregular, reddish brown, necrotic patches. A gray mold may or may not be observed

on the leaf.

If flowers are infected, before bloom, they will wither or dry out and fall off the vine Girdling of the rachis causes any berries

below the infection site to wither and drop off.

http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=514.00000

+Botrytis Bunch Rot – Fruit Symptoms

Most common infection.

After veraison, grapes are infected through the epidermis or wounds. Develops faster in tight clusters where

berries are compressed together.

Infected berries will appear in late summer. Small brown spots on maturing berries The skin may slip off easily when rubbed. If the weather is dry the grapes will dry out. Wet weather will cause them to burst.

Photo by Jay W. Pscheidt, Oregon State University

+Botrytis Bunch Rot – Disease Cycle Overwinters on debris in the vineyard floor or vine.

Later in the season, hyphae will penetrate directly through the epidermis of the berries that were not infected during bloom.

Wounds caused by insects, powdery mildew, hail or birds greatly help to facilitate infection.

After infecting the berry, Botrytis may stay dormant until the fruit sugar content increases and the acid level decreases.


+Botrytis Bunch Rot – Control Strategies

Minimize humidity Select a site where vines are exposed to sun all day. Utilize pruning and training systems to improve air circulation. Avoid applying excessive nitrogen that will stimulate lush growth. Remove leaves around the grape cluster at shatter Proper weed control and good soil drainage.

Choose resistant cultivars, such as Frontenac and Frontenac Gris

Spray timing The first spray is at the end of bloom or the beginning of fruit set. The second application is just before berry touch. The third is at the start of veraison, and the last is three weeks

before harvest if rain is expected.

+Botrytis Bunch Rot – Noble Rot

Under specific climatic conditions Botrytis cinerea is known as the noble rot.. Temperature needs to be between 68-77oF (20-25oC) during the infection phase.

Relative humidity needs to be between 85-95%.

Once the infection has occurs the relative humidity needs to drop down to 60% - Key to creating Noble Rot.

Botrytis cinerea creates many changes within the berry. The mycelium penetrates the grape skin allowing the berry to dry.

This dehydration leads to a concentration of sugars.

The osmotic pressure inside the berry causes the metabolic activity of the pathogen to decrease enabling vintners to create the sweet botrytised wine.

The mold consumes 35-45% of the sugar from the berry, but overall concentration increases due to dehydration.

Tartaric and malic acids are metabolized, increasing the pH of the must.

It also destroys aroma components, such as terpenes and phenolic compounds, which make it detrimental to red wine production.

Special techniques need to be used by the vintners. ferments much slower

Skin contact should be very minimal to avoid contact with any secondary molds.

It is necessary to continually monitor the volatile acidity during and after fermentation to protect the wine from oxidation

The high-density of the juice makes it difficult to clarify the wine

Unlike other wines, it is racked every three months for one year. It is then fined at the end of the first and second year.

+Anthracnose - Overview

Grape anthracnose, also called bird’s-eye rot

Not a native pathogen to the U.S.

Anthracnose is economically important Reduces fruit quality and yield, as well as weaken the

vine.

Currently a minor problem in Minnesota. Prefers warm, humid climates.

Symptoms Lesions on shoots and berries, are most commonly observed. Infects the stems, leaves, tendrils, young shoots and berries.

+Anthracnose – Vegetative Symptoms

Young shoots Small isolated lesions. Can cause shoots to crack and become brittle. Can be confused with hail damage.

Look for raised black edges.

Young leaves are most susceptible to anthracnose. Circular lesions with brown or black margins. The center tissue will eventually drop out of the

lesion creating a “shot-hole” appearance.

If veins are infected malformation or complete drying of the leaf will occur.

http://ohioline.osu.edu/hyg-fact/3000/3208.html


+Anthracnose – Fruit Symptoms

Berry clusters are susceptible before flowering through veraison.

Small, reddish circular spots.

The center of the lesion becomes whitish gray giving rise to “bird’s eye rot”.

Can causing cracking and opening the berry to secondary infections


+Anthracnose - Disease Cycle

Temperature and moisture are the key components in influencing disease development. (Higher the better)

Spreads through free water within 12 hours of rain.

Symptoms develop within 4-13 days, depending on temperature.

+Anthracnose – Control Strategies Sanitation

Prune out and destroy any diseased parts from the vines or vineyard floor, during dormant season.

Remove all wild grapes near the vineyard. Act as an excellent source of inoculum and the disease can

develop unnoticed. Clear them from surrounding fence rows.

Spray Timing A dormant application of liquid lime sulfur should be applied

prior to bud break. Followed by foliar applications of fungicides, every two weeks

from bud break to veraison.

Organic growers can use Lime Sulfur or copper sprays.

+Bitter Rot - Overview

Fungus creates a very bitter taste in infected berries

Not yet observed in Minnesota. May become an issue for Minnesota

growers as our climate changes.

Symptoms Easily confused with those of black rot. Brown lesions only on ripe grapes, not

on green grapes like black rot. Lesions spread around the berry, in

concentric circles over a short period of time.



+Bitter Rot - Continued

Disease Cycle Overwinters in plant debris in the vineyard. Fungal growth is favored by warm, humid, wet weather.

Control Strategies Sanitation

Clear all mummies from the ground after leaf drop or till them into the soil prior to bud break.

Air Circulation Utilize pruning and training systems to promote rapid leaf

drying. Full spray coverage and canopy penetration.

+Sour Rot

Not yet observed in Minnesota. May become an issue for Minnesota growers as our

climate changes.

Caused by various undesirable yeasts and bacteria rather than a single pathogen.

Impacts both grape yield and wine quality. Infected grapes give an unpleasant, vinegary finish to

wines and increases volatile acids.

+Sour Rot - Continued

Symptoms Grapes leak juice that smells like vinegar. White cultivars will appear brick colored and red cultivars

will appear purple or brown. Large numbers of fruit flies are common and will spread

the infection to other clusters.

Sour rot infection is favored by warm, humid, wet weather and tight clustered cultivars.

Control Pruning and training systems to improve air circulation

which promotes rapid leaf drying. Remove leaves between fruit set and veraison.

+Thank you

Please visit our web site at http://fruit.cfans.umn.edu/grape/IPM/grapeipmguide.htm for Web pages and PDF formats of each Pest and Pathogen.

Questions?

+References

Agrios, G.N. 2005, Plant Pathology, Fifth Edition, Elsevier Academic Press, pg. 427-433, 483-484, 556-557,

Broiembsen, S. Pratt, P. Black Rot of Grapes, Oklahoma Cooperative Extension Service, http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-1011/F-7643web.pdf

California Food and Wine Magazine, 2007, Golan Heights Winery Develops Botrytis Technology in Venture with Tel Aviv University, http://www.californiawineandfood.com/wine/golan-heights-botrytis-venture.htm.

Dharmadhikari, M. Accessed 2007, Botrytis cinerea in Winemaking, Iowa State University Extension, http://www.extension.iastate.edu/NR/rdonlyres/173729E4-C734-486A-AD16-778678B3E1CF/56372/botrytiscinerea1.pdf

Ellis, M. Doohan, D. Bordelon, B. Welty, C. Williams, R. Funt, R. Brown, M. 2004. Midwest Small Fruit Pest Management Handbook. The Ohio State University Extension. 125-138, http://ohioline.osu.edu/b861/.

Hartman, J. Hershman, D. 1988, Black Rot of Grapes, www.ca.uky.edu/agc/pubs/ppa/ppa27.htm.

How to Manage Pests, 2006, University of California Statewide Integrates Pest Management Program, http://www.ipm.ucdavis.edu/PMG/r302100311.html.

Jackisch, P. 1985, Modern Winewmaking, Cornell University Press, pg. 173-174.

Pearson, R. Goheen, A. 1998. Compendium of Grape Diseases, pg. 9-16, 18-19,

Pscheidt, J. 2007, Grape-Powdery Mildew, Oregon State University Extension.

Ramsdell, D.C. Common Diseases of the Grapevine in Michigan, Michigan State University Extension.

Rombough, L. 2002, The Grape Grower, A Guide to Organic Viticulture, Chelsea Green Publishing, pg.90-92, 97-101,

Travis, J. Saunders, M. Hed, B. Muza, A. Timer, J. Wicox, W, 2006, Integrated Management of Organic Concord Grape Production in the Lake Erie Region, The New Tork Wine/Grape Foundation, The Viticulture Condortum-East.

Wilcox, W. 2003, Grape Disease Identification sheet, Cornell University Cooperative Extension, http://www.nysipm.cornell.edu/factsheets/grapes/diseases/grape_pm.pdf.

Cox, J. 1999, From Vines to Wines, The Complete Guide to Growing Grapes and Making Your Own Wine, Storey Publishing.

Chein, D. 2003, 2-4D Herbicide Drift Into Vineyards, Penn State Wine Grape Extension Newsletter, http://winegrape.cas.psu.edu/grapevine/gv_1-01/gv_herbicide_drift.html.

Dirr, M. 1998, Manual of Woody Landscape Plants, 5th ed, Stipes Publishing LLC.

Goode, J. 2005, The Science of Wine, From Vine to Glass, Octopus Publishing Group. LLC.

Law, J. 2005, The Backyard Vintner, An Enthusiast’s Guide to Growing Grapes and Making Wine at Home, Quarry Books.

Nail, W. accessed 2007, Critical Issues in Early Vineyard Establishment, Connecticut Agricultural Experiment Station.

Rombough, L. 2002, The Grape Grower, A Guide to Organic Viticulture, Chelsea Green Publishing.

Winkler, A.J. Cook, J. Kliewer, W.M. Lider, L. 1975, General Viticulture, University of California Press.