Armillaria Root Rot

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Armillaria Root Rot I selected this because

My property had many trees remove but roots where left

I have seen symptoms in one small area of Vineyard

It’s prevalent in your area of California

General information

BRE Properties, Inc.2

It’s a fungus, loves cool moist soil

• Infects woody roots & trunk base

• Effects large variation of plants

• Difficult to stop • Slow death of the plant

Signs & Symptoms

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Mushrooms Fully bloom

First sign can be Aug

Short weak shoots Small clusters Poor ripening Low NPK in Petiole lab tests

Signs & Symptoms

Leaves turn red Wilted leaves Early defoliation Death is normally during dormancy

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Sign & symptoms

Mushrooms – needs moisture. Doesn’t act as disease spreader

Near former diseased trees

Vine productivity slows and die 2-4 years

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Signs, Symptoms & Diagnose

Base of trunk just under the surface.

White Mycelial under the bark near

Light brown spongy wood

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Signs, Symptoms & Diagnose

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rhizomorphs very rare in vines

Can spread to vine planted near diseased areas under ground

Will decrease in severity as move away from infected center

This is one way of control

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Disease cycle

Fungus is present in soil as part of old tree roots & stumps

Vine roots come in contact with infected area

These are colonized and become inoculum and released as spores

Vine tissues are attacked and spreads to root collar

Trunk is girdled and eventually incapable of supporting vine

Management – preplanting

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Avoiding land with history of trees or disease

Ripping and removal of roots

Fumigation chemicals

Stay updated via UCDavis options

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Management post plant Several

options ID the smaller infected area and don’t plant

Keep area dry, drips lines

Monitor and know your land history

Early season

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In spring clear soil around base of vine expose upper roots to air out and dry 12-16 inches.

This can be very effective and can be perminate if done early life of vine

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More on ControlsSuccess of chemicals is dependent on drainage, site slope and site orientation…. Dry soil

Best done before planting or in dormant season

Biological Microbial control is showing promise in the form of a bacterial strain that inhabits the pathogen development

Resistant roots stocking is being developed, but not yet on market

Treatments – Sept - Nov

When choosing a pesticide, consider the environmental impact. METHYL BROMIDE – see label rates  COMMENTS: Preplant treatment. May only be used under a

Critical Use Exemption. Fumigants such as methyl bromide are a source of volatile organic compounds (VOCs) but are not reactive with other air contaminants that form ozone: methyl bromide depletes ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available.

METAM SODIUM - (Vapam, etc.) COMMENTS: Apply in winter when soil moisture is high.

Fumigants such as metam sodium are a source of volatile organic compounds (VOCs) but are minimally reactive with other air contaminants that form ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available.13

My question for the Final

The Armillaria fungus thrives best in what type of soil

a – Hot wet soilb – Cool moist soilc. – Dry warm soild.- Dry cool soil

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The End

Any questions ?

Next presenter please

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