ITGP 2007 Disease Mgmt

Emerging Issues in Extension Plant Pathology Don Hershman Paul VincelliKenny Seebold John Hartman*

Paul Bachi and Julie BealeEd Dixon, Brenda KennedyBernadette Amsden, Terry Yielding, Sara LongMindy Thompson * Retired, working half-time1Grain CropsDon Hershman: Soybean and WheatPaul Vincelli: Corn2Soybean Cyst NematodeDevelopment of new races has compromised effective use of resistant varieties.

Seed treatments may or may not be helpful, but they will soon be marketed.

3Soybean Rust Monitoring, Management and Networking

4Soybean Rust Monitoring, Management and Networking

5Soybean Rust Yield Loss Calculator

Cooperative project with Saratha Kumudini6Plant Health Fungicide Use in Corn and SoybeanApproximately 35% of Kentuckys corn and soybean acres are being treated with a fungicide.7Plant Health Fungicide Use in Corn and SoybeanApproximately 35% of Kentuckys corn and soybean acres are being treated with a fungicide.Many acres are being treated in an attempt to capture Plant Heath8Plant Health Fungicide Use in Corn and SoybeanApproximately 35% of Kentuckys corn and soybean acres are being treated with a fungicide.Many acres are being treated in an attempt to capture Plant HeathMost spray decisions are being made without considering disease risk.9Plant Health Fungicide Use in Corn and SoybeanApproximately 35% of Kentuckys corn and soybean acres are being treated with a fungicide.Many acres are being treated in an attempt to capture Plant HeathMost spray decisions are being made without considering disease risk.Addressing issue with aggressive Extension program and cooperative research projects.10Plant Health Fungicide Use in Corn and SoybeanApproximately 35% of Kentuckys corn and soybean acres are being treated with a fungicide.Many acres are being treated in an attempt to capture Plant HeathMost spray decisions are being made without considering disease risk.Addressing issue with aggressive Extension program and cooperative research projects.Have provided national leadership on this issue.

11Southern Rust of Corn2009 outbreak in KY and Corn Belt was a wake-up call.Some yield loss in KY.Dies back to the southern gulf each year.Coordinated monitoring project, akin to SBR, is being initiated.Taking leadership in diagnostics.

122009 National PCR Workshop

National leadership on the use of DNA-based diagnostics, as for six years now we have had waiting lists for these workshops.13Wheat Head Blight/DONSignificant disease outbreaks occur 1 in 5 years in Kentucky.

Current and future efforts are aimed at maximizing disease control through integrated use of resistant varieties and fungicides.

Part of a national research team.

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Helping to Refine Risk Tool15UG-99 Wheat Stem RustMost wheat varieties are susceptible

Should be here within 5 years

KY is not at great risk, but we are at risk.

KY is a participant in on-going monitoring efforts.

16Tobacco and Vegetable CropsKenny Seebold17Blue MoldPeronospora tabacinaFast-moving,devastating foliar disease of tobacco under favorable conditionsAlso known as downy mildew of tobaccoPathogen is air-dispersed primarilyFungicide efficacy trials are on-going and Blue Mold Warning System has been a high priority.

18Work on this disease has focused mainly on screening new fungicides for control. Weve demonstrated the effectiveness of Quadris, now labeled, for managing blue mold. Ive also tested newer products such as fenamidone (Reason), which is highly effective and will receive a Section 3 label in 2010 or 2011 for tobacco.Has become serious problem in transplant and field production (losses up to 400 lbs/A)Quadris 24c label obtained for disease control in greenhouse.Research has suggested adequate control possible using Quadris. More work needed on rates and timing.

Target SpotSymptoms & Signs Field (Burley)

19Phytophthora nicotianae Most damaging disease of KY tobacco Integrated control of black shank (fungicide x variety) is on-going.

Black Shank

20Emerging Vegetable Disease Situations

Fungicide ResistanceCucurbit Powdery MildewTomato Early Blight21Emerging Vegetable Disease Situations

Phytophthora blight ofCucurbits, peppers andtomatoes22New Strain of Watermelon Mosaic in KY

AgDia results: Positive for potyvirus,negative for all virus-specific tests Images courtesy Kenny SeeboldFor several years now, many cases of cucurbit virus disease outbreaks throughout the East have been positive by AgDias potyvirus test but negative for all the individual virus ELISAs. No one knew whether it was a new strain of a well-known virus or a new virus. Last year, I did the virus sequencing work to determine that a new, undetected strain of watermelon mosaic virus was responsible for a case of this in Kentucky. This was the first time in the U.S. that the identify of one of these cases was determined.23Fruit, Woody and Ornamental CropsJohn Hartman24Emerging Woody Plant IssuesSudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.Both diseases have severely impacted nursery industry.25Emerging Woody Plant IssuesSudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.Both diseases have severely impacted nursery industry.Pierces disease on increase in KY and threatens fledgling grape/wine industries.26Emerging Woody Plant IssuesSudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.Both diseases have severely impacted nursery industry.Pierces disease on increase in KY and threatens fledgling grape/wine industries.Devastating black walnut fungal canker is making its way towards KY.27Emerging Woody Plant IssuesSudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.Both diseases have severely impacted nursery industry.Pierces disease on increase in KY and threatens fledgling grape/wine industries.Devastating black walnut fungal canker is making its way towards KY.Fungicide resistance to apple scab and grape black rot fungi is on the increase.28Emerging Woody Plant IssuesSudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.Both diseases have severely impacted nursery industry.Pierces disease on increase in KY and threatens fledgling grape/wine industries.Devastating black walnut fungal canker is making its way towards KY.Fungicide resistance to apple scab and grape black rot fungi is on the increase.These issues are currently not being adequately addressed in KY.29DNA-based identification of the soybean cyst nematode assists nursery industry

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We continue to do a lot of behind-the-scenes work to maintain our diagnostics at the cutting edgerelying on traditional techniques as much as we can but advancing our techniques into DNA-based diagnostics when the situation warrants. You can describe this as an example. The test is on the cusp of being ready; just one or two more experiments in how to best handle a single cyst.

30On-Going Issues of ImportancePlant Disease Diagnostic ClinicsHorticulture and ANR Agent Training initiatives.Developing and refining disease management recommendations through applied research.Kentucky Pest News.Stakeholder training.Expanded WWW presenceWebsites, blogs, Twitter, listservs, etc.31Questions?

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