Grape Virus Update Southern Oregon Grape Symposium

John Duarte, President Duarte Nursery

What is going on? How much do we know? What should growers do?

What is going on? DNI has invested heavily in testing and

replanting increase blocks since 2012.

Our increase blocks are cleaner than ever. We are delivering the cleanest plants ever.

New viruses are emerging and several viruses are spreading.

Customers are calling with 3rd-5th year virus problems.

What are clean plants?

Only QA scion and rootstock at DNI

Testing A. Increase blocks B. Inspection C. Replanting

Transparency A. Plant health Reporting B. Testing results

Traceability A. Source blocks, grafting, growing origins. B. Who else received the same materials.

Duarte Clean Plant Program Virus:

Testing Mother Blocks 388,072 scion & rootstock

All blocks walked by DNI and CDFA 40,213 vines tested in 2015 Visually symptomatic= 288 59 vines tested pos.

GRBaV = 14 vines GLRV3-9 = 42 vines GVB = 3 vines

Removed Buffer vines = 2,924 vines 00.03% infected or suspect.

Clean Mother Blocks

For 2016 Duarte Nursery has:

28.1 Million Certified Buds 1.5 Million 2010 Protocol Buds

Total 29.6 Million Buds

2010 Protocol from FPS

Planting of 2010 Protocol in 2016

2017= 55,000 buds 2018= 275,000 buds 2019= 825,000 buds

5500 vines of 2010P Spring 2016

Transparency Variety Clone Ranch Block 2010 Protocol Custom Client Testing

Plant Health Report

Field Testing Maps

We dont know how some viruses spread. GVRBaV LRV1-n

We cant predict adjacency spread rates.

We cant quantify mosaic spread rates.

Replant site reinfection is becoming suspicious.

How much do we know?(2)

Pinot Gris 152 on 5C

Red Blotch Symptoms in Whites

Chardonnay next to the PG

ADJACENCY Red Blotch Symptoms in Whites

4th Leaf Red Blotch Infection

4th Leaf Leafroll Infection

Whats Next?

closely related to Grapevine berry inner necrosis virus; which is spread easily by Eriophyid mites.

eliminated easily by in vitro meristem tip culture and/or thermotherapy

*Winesandvines.com

Grapevine Pinot Gris Virus

First Vector of Red Blotch

Three-Cornered Alfalfa Hopper Girdling is caused by late instar nymphs more than by adults common and widespread Host range= fruit trees, shrubs, herbs, and grasses

Smith R. 1992. Three-Cornered Alfalfa Hopper. Page 249 in: Grape Pest Management, 2nd edition.

Insect Suppression Mealy bugs, Leafhoppers,? Eriophyid mites supressed by sulfur.

What should growers do? Insect suppression.

Have a replanting plan: Manage adjacency Fallow period of 12 18 months.

Test and inspect nursery source blocks.

Test and inspect nursery vines in fall and deliveries.

Rogue new plantings annually. Replant if less than 1-2% in a year. Rogue and plan for replant if over 5%

Strategies

Simple higher density vineyard design (VSP).

Plant for easier vine removal: Less wrapping of cordons Away from line stakes

Use higher production clones.

Use more vigorous rootstocks.

Use larger format more mature grapevines.

Emerging Industry Practice Ubervine, Magnum, Standard sales from Duarte

Nursery, Inc. 2012-2016

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2012 2013 2014 2015 2016

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Std 12" vine Ubervine 35" with 1/2 crop Ubervine 25" with full crop

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TPA

Larry Bettiga, Viticulture Farm Advisor, Cooperative Extension Monterey.

5t. Accelerated production in 3y.

18 month old Ubervines

Grape Virus UpdateSouthern Oregon Grape SymposiumSlide Number 2What is going on?Slide Number 4Only QA scion and rootstock at DNIDuarte Clean Plant Program Virus:Testing Mother Blocks388,072 scion & rootstockSlide Number 8Slide Number 9Slide Number 10Slide Number 11TransparencyPlant Health ReportField Testing MapsHow much do we know?(2) Slide Number 16Slide Number 174th Leaf Red Blotch Infection4th Leaf Leafroll InfectionWhats Next?Slide Number 21Slide Number 22What should growers do?StrategiesSlide Number 25Emerging Industry PracticeUbervine, Magnum, Standard sales from Duarte Nursery, Inc. 2012-2016Advanced ProductionSlide Number 28Slide Number 29