N I C O L E W A R D G A U T H I E R , U K P L A N T PAT H O L O G Y

SANITATION: PREVENTATIVE DISEASE MANAGEMENT IN

KENTUCKY VINEYARDS

WHY WASH YOUR HANDS?

Shopping carts

Door knobs

Money

Escalator rails

WHAT ARE PLANT PATHOGENS?

• Fungi•Bacteria• Viruses•Nematodes•Water-molds

HOW ARE DISEASES MANAGED?DISEASE TRIANGLE

Disease

OBJECTIVES

What should you learn?

• Basic biology of major grape pathogens

• Understand overwintering of these pathogens

• Methods for preventing inoculum build-up and overwintering

PREVENTATIVE FUNGICIDE APPLICATIONS

Early season• Powdery mildew• Downy mildew• Black rot• Phomopsis cane and leaf spot

• 1-3” green through 3-4 weeks after bloom

Late season• Powdery mildew• Downy mildew

• 3-4 wks after bloom through harvest

EARLY SEASON DISEASES

Early season infections• Powdery mildew• Downy mildew• Black rot• Phomopsis

Most critical phase

Pathogens break dormancy

Begins with prevention

What if pathogens weren’t there in the first place?

PHOMOPSIS

Phomopsis• Cool weather disease

34˚F/74˚F

• Pre-bloom sprays

• Fruit infected before and during bloom

• Fungus remains dormant

• No symptoms development on fruit until ripening

• Cane and leaf spot symptoms all season

• Fungus sporulates through full-bloom

• Early season control

PHOMOPSIS

PHOMOPSIS

POWDERY MILDEW

Powdery Mildew • Infections begin pre-bloom

• Pre-bloom sprays

• Arid conditions

• .01” rain and 50˚F ascospore discharge

• Repeating disease cycle

• Control of initial infections

• Berries become resistant 2-4 weeks after bloom

• Cluster stems (rachis) and leaves remain susceptible throughout season

POWDERY MILDEW

POWDERY MILDEW

POWDERY MILDEW

POWDERY MILDEW

POWDERY MILDEW

DOWNY MILDEW

Downy Mildew • Infections begin pre-bloom

• Pre-bloom sprays

• .4” rain and 50˚F and 4” vine growth for oospore germination

• Water mold, swimmers

• Control of initial infections

• Berries become resistant 3-4 weeks after bloom

• Cluster stems (rachis) and leaves remain susceptible throughout season

DOWNY MILDEW

DOWNY MILDEW

DOWNY MILDEW

DOWNY MILDEW

DOWNY MILDEW

BLACK ROT

Black rot• Infections begin pre-bloom

• Pre-bloom sprays

• Control of initial infections

• Berries become resistant 3-4 weeks after bloom

• Susceptible from early bloom through berry touch

• Overwinters in mummies

• Young leaves are susceptible, mature leaves are resistant

• Petioles and shoots susceptible, cankers develop

BLACK ROT

BLACK ROT

BLACK ROT

OTHER IMPORTANT DISEASES

There’s more than the BIG 4

• Eutypa dieback

• Cankers lead to dieback

• Sporulates in old cankers

• Enter though wounds, pruning wounds

• Early spring

• Sanitation, canker removal

OTHER IMPORTANT DISEASES

There’s more than the BIG 4

• Grape Anthracnose

• More common during warm, wet spring

• Can become serious

• Sporulates from cankers and leaf debris

• Lime sulfur at end of dormancy (delayed dormant application)

OTHER IMPORTANT DISEASES

There’s more than the BIG 4

• Botrytis Bunch Rot

• Common in tight-clustered varieties (V. vinifera)

• Sanitation

• Air circulation

• Fungicides, bloom & veraison

• Rovral

• Vangard

• Elevate

OTHER IMPORTANT DISEASES

There’s more than the BIG 4

• Crown Gall

• Common in V. vinifera

• Enters through wounds, especially winter injury

• Biological controls help suppress disease, but no cure

• Gallex

• Galltrol A

• Norbac 84C

WHAT’S THE PATTERN HERE?

EARLY SEASON INFECTIONS• Phomopsis• Powdery mildew• Downy mildew• Black rot

• Infection takes place from immediate pre-bloom through 2-4 weeks after bloom

How should you manage these diseases?

ELIMINATE OVERWINTERING

INOCULUM!

PREVENTATIVE PROGRAM

Remove disease-causing pathogens from vineyards before sporulation.

• Approximately 70% of infective propagules removed through sanitation

• Fungicides prevent repeating cycles and re-infections

CHALLENGES

Sanitation does not offer immediate disease management

• Reduction of infective materials• Combined with fungicides

Manual labor• Prune into carts• Burn or bury• Harvest everything

Most noticeable during seasons with high disease pressure

QUESTIONS?WWW.SLIDESHARE.NET/NICOLEWARDUK

Nicole Ward Gauthier Extension Specialist

Department of Plant Pathologywww.ca.uky.edu/agcollege/plantpathology/people/ward.htm

nicole.ward@uky.edu

859-218-0720 office859-797-3333 mobile/text

Facebook: www.KYPlantDisease.comUK - Diseases of Fruit Crops, Ornamentals, & Forest Trees

Twitter: @Nicole_WardUK

Blogger: nicolewarduk.blogspot.com