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Grape disease control Update for 2015

Mike Ellis

Department of Plant Pathology

The Ohio State University, OARDC

Resources for Grape Disease Control and Pest Management

Ohio State University Extension Bulletins:

• Midwest Small Fruit and Grape Commercial Spray Guide

• Midwest Grape Production Guide

Ohio State University Extension State Specialists:

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New developments in Fungicides for Grape

Disease Control

Torino 0.85% Liquid

Fungicide for control of powdery mildew only on grape

3.4 fl oz / APHI= 3 days

No more than 2 applications per season

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Vivando 2.5F

Fungicide for Control of Powdery mildew on Grape

10.3 to 15.4 fl oz/A

14 day PHI

There have been several new fungicides recently registered for use on grapes in Ohi0

Four new fungicides have been registeredfor control of Downy Mildew

• Revus 2.08F - mandipropamid (Syngenta)

• Presidio 4L - fluopicolide (Valent)

• Forum 4.17F - dimethamorph (BASF)

• RANMAN 3.33F - cyazofamid (FMC)

• All of these materials provide good to excellent control of downy mildew

• They are all in different classes of fungicide chemistry- important for resistance management

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Use rates and PHI

• Revus 2.08F (8 fl oz/A) PHI=14 days

• Presidio 4L (3-4 fl oz/A) PHI=21 days

• Forum 4.17F (6 fl oz/A) PHI=28 days

• RANMAN 3.33F (2.1-2.75 fl oz/A) PHI-30 days

Switch and ScalaRecently Registered for Control of

Botrytis Bunch Rot

• Switch 62.5 WG is a combination product form Syngenta.

Cyprodinil (Vangard) plus fludioxanil

• Scala 5SC (pyrimethonil) is similar chemistry to Vangard and is a product of Bayer.

• Both materials provide excellent control of Botrytis bunch rot but do not control other diseases. They are different chemistry.

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Several new Combination products(Package Mixes)

were recently registered

• Revus Top (difenoconazole + mandpropamid)(sterol inhibitor) + (Revus)

• Quadris Top (difenoconazole + azoxystrobin)(sterol inhibitor) + (Abound)

• Inspire Super (difenoconazole + cyprodinil)(sterol inhibitor) + (Vangard)

• Quilt Xcell (propaconazole) + (azoxystrobin)(sterol inhibitor) + (Abound)

• Revus Top (sterol inhibitor) + (Revus)

Controls black rot, powdery, downy mildew and anthracnose

• Quadris Top (sterol inhibitor) + (Abound)

Quilt Xcell (sterol inhibitor) + Abound)

Controls black rot, powdery, downy mildew, anthracnose and suppression of Phomopsis and Botrytis fruit rot

(Be aware of apple Phytotoxicity from Abound)

• Inspire Super (sterol inhibitor) + (Vangard)

Controls black rot, powdery mildew and anthracnose

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Use (rates) and PHI

• Revis Top (7 fl oz/A) 14-Day

• Quadris Top (10-14 fl oz/A) 14-DAY

• Inspire Super (16-20 fl oz) 14-DAY

Warnings on fungicides

• Difenoconazole (sterol inhibiting fungicide) one of the components in the following package mixes:

Revis top; Inspire super; and Quadris Top

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Note on difenoconazole (potential phytotoxicity)

Inspire Super, Quadris Top and Revus Top fungicides all contain difenoconazole as one of their active ingredients. The following PRECATION STATEMENT has been placed on all

fungicides containing difenoconazole that are registered for use on grapes.

“ PRECATION: on V. labrusca, V. labrusca hybrids, and other non-vinifera hybrids where sensitivity is not known, the use of

Inspire Super, Quadris Top, or Revus Top by itself or in tank mixes with materials that may increase uptake (adjuvants, foliar fertilizers) may result in leaf burning or other phytotoxic effects”.

Notes on Revus Tops

• Looks very good for use in the critical period (immediate prebloom through 4 to 5 weeks after bloom) for control of black rot, powdery mildew and downy mildew, or late season for control of powdery and downy mildew.

• Cost is about $17.00 /A

• Can’t be used on Concord or other Labrusca type grapes. (Difenoconazole)

• Apparently no problem on Vinifera or French

hybrids.

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Warnings on fungicides

Fungicide resistance concerns

Phosphorous acid fungicides

Strobilurins

Phosphorous Acid (phosphite) Fungicides

There are many products on the market

• Agri Fos

• ProPhyt

• Phostrol

• Topas

• Rampart

• Aliette

• Legion

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We do not have a problem with resistance yet, but we need to use fungicide resistance

management strategies with these and most other fungicides

• Apply in 2-spray alternations with a different class of chemistry

• Use a limited number of applications per season.

Warnings on fungicides

Fungicide resistance concernsStrobilurins

Abound, Cabrio, Flint, Sovran

(Quadris Top, Quilt Xcell, Pristine)

We have used these materials for several years now and I think there is a good possibility that we have some resistance or at least reduced sensitivity to these materials in:

Downy and Powdery Mildew.

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The strobilurin fungicides have a chemistry that is at high risk for resistance development. When resistance

does occur it is “Qualitative” which means it is all or nothing and it does not go away with time. They were

introduced on grape (Abound) in the late 1980s

Resistance developed top powdery mildew several years ago and it appears that resistance to downy

mildew has developed as well.

If these materials have been used for several years in your vineyard,

I do not believe that these materials should be used for control of powdery and downy mildew

on grapes in Ohio

Warnings on fungicides

Abound (azoxystrobin) is very phytotoxic to certain varieties of apples.

Abound, Quadris Top, Quilt Xcell

If these materials are used, you cannot use the same sprayer for making sprays on apples.

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New fungicides registered on grapes

Zampro

• New fungicide registered for control of Downy mildew only on grape. Does not control any other grape diseases.

• Product of BASF

• Ametoctradin (new chemistry)

plus

Dimethomorph (Forum)

• Very good for control of downy mildew.

• Use rate = 11(5) to 14 (4) fl oz / A PHI = 14 days

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Zampro is great stuff.

I had a “control” treatment that started in late May with Phostrol, then just two more sprays of Zampro at 4-wk intervals during the summer, when inoculum was high and pressure intense.

The early Phostrol + two Zampro sprays gave almost complete control of disease severity, whereas vines in the UTC and several strobilurin programs were completely defoliated by early September (looks like we’ve got strobilurin resistance!).

I think this is a fungicide that all grape growers need to be aware of.

It may be the best material for control of downy mildew since

Ridomil (Mefanoxam).

It is not Cheap!

11-14 fl oz / A = $27-$35 / A

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Tavano 5% SC

• Active ingredient= Polyoxin D zinc salt

• It is an antibiotic

• Registered on grape for control of:

Gray mold (Botrytis bunch rot) and Powdery Mildew

• Use rate 3.75 - 13 fl oz / A PHI=0 days

• I do not have experience with this product

Reason• A product of BAYER

• Registered for control of Downy mildew only on

grape

• Active ingredient is Fenamidone

• Same class of chemistry as Strobilurins

• Use rate 2.7 fl oz / A PHI = 30 days

• Resistance is a big potential problem

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We have lost a couple of fungicides

• Elite is a products of (Bayer). It was removed from removed the market about a year ago.

• Elite has the active ingredient Tebuconazole. It is a sterol inhibitor and is an excellent material for control of powdery mildew and black rot. I see it as similar to Rally used at the same rate, but a bit less expensive.

• There are several generic products with tebuconazole as the active ingredient.

• Tebuzol 45 DF is one of them. The generic products tend to be less expensive. You should check them out.

Rally 40W (Nova 40W) 3-5 oz $9.60

Elite 45 DF (no longer available) 4 oz $15.50

Tebuzol 45 DF (Generic Elite) 4 oz $5.50

Torledo 45 DF(Generic Elite) 4 oz $4.60

Note: It may pay you to check out Generic Fungicide Products.

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Grape Anthracnose

Anthracnose has developed in several vineyards across Ohio

The incidence of Anthracnose has increased significantly

and is a disease we need to keep a close eye on.

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Sour Rot

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Controlling Black Rot,

Powdery Mildew,and

Downy MildewFruit (Cluster) Infections

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Most Critical Period For Controlling Grape Diseases With Fungicides

Immediate Pre-bloom

Through

3 to 4 weeks after bloom

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Why is this period so Critical?

By 3 to 4 weeks after bloom, the fruit develop

“ONTOGENIC RESISTANCE”

and the fruit are not longer susceptible to infection by

Black Rot, powdery and Downy Mildew

That Concludes my Presentation

Thank You

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Mike EllisOARDC

Dept. of Plant Pathology1680 Madison Ave.

Wooster, Ohio 44691Phone: 330-263-3849Email: ellis.7@osu.edu