Emerging Issues in Extension Plant Pathology

Don Hershman Paul VincelliKenny Seebold John Hartman*

Paul Bachi and Julie BealeEd Dixon, Brenda Kennedy

Bernadette Amsden, Terry Yielding, Sara LongMindy Thompson

* Retired, working half-time

Grain Crops

Don Hershman: Soybean and WheatPaul Vincelli: Corn

Soybean Cyst Nematode

• Development of new races has compromised effective use of resistant varieties.

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

Soybean Rust Monitoring, Management and Networking

Soybean Rust Monitoring, Management and Networking

Soybean Rust Yield Loss Calculator

Cooperative project with Saratha Kumudini

“Plant Health” Fungicide Use in Corn and Soybean

• Approximately 35% of Kentucky’s corn and soybean acres are being treated with a fungicide.

“Plant Health” Fungicide Use in Corn and Soybean

• Approximately 35% of Kentucky’s corn and soybean acres are being treated with a fungicide.

• Many acres are being treated in an attempt to capture “Plant Heath”

“Plant Health” Fungicide Use in Corn and Soybean

• Approximately 35% of Kentucky’s corn and soybean acres are being treated with a fungicide.

• Many acres are being treated in an attempt to capture “Plant Heath”

• Most spray decisions are being made without considering disease risk.

“Plant Health” Fungicide Use in Corn and Soybean

• Approximately 35% of Kentucky’s corn and soybean acres are being treated with a fungicide.

• Many acres are being treated in an attempt to capture “Plant Heath”

• Most spray decisions are being made without considering disease risk.

• Addressing issue with aggressive Extension program and cooperative research projects.

“Plant Health” Fungicide Use in Corn and Soybean

• Approximately 35% of Kentucky’s corn and soybean acres are being treated with a fungicide.

• Many acres are being treated in an attempt to capture “Plant Heath”

• Most 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.

Southern Rust of Corn

• 2009 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.

2009 National PCR Workshop

Wheat Head Blight/DON

• Significant 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.

Helping to Refine Risk Tool

UG-99 Wheat Stem Rust

Most 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.

Tobacco and Vegetable Crops

Kenny Seebold

Blue MoldPeronospora tabacina

Fast-moving,devastating foliar disease of tobacco under favorable conditions

Also known as “downy mildew of tobacco” Pathogen is air-dispersed primarily Fungicide efficacy trials are on-going and Blue Mold Warning

System has been a high priority.

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)

- Phytophthora nicotianae- Most damaging disease of KY

tobacco- Integrated control of black shank (fungicide x variety) is on-going.

Black Shank

Emerging Vegetable Disease Situations

Fungicide ResistanceCucurbit Powdery MildewTomato Early Blight

Emerging Vegetable Disease Situations

Phytophthora blight ofCucurbits, peppers andtomatoes

New Strain of Watermelon Mosaic in KY

AgDia results: Positive for potyvirus,negative for all virus-specific tests

Images courtesy Kenny Seebold

Fruit, Woody and Ornamental Crops

John Hartman

Emerging Woody Plant Issues

• Sudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.– Both diseases have severely impacted nursery

industry.

Emerging Woody Plant Issues

• Sudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.– Both diseases have severely impacted nursery

industry.• Pierce’s disease on increase in KY and

threatens fledgling grape/wine industries.

Emerging Woody Plant Issues

• Sudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.– Both diseases have severely impacted nursery

industry.• Pierce’s disease on increase in KY and

threatens fledgling grape/wine industries.• Devastating black walnut fungal canker is

making its way towards KY.

Emerging Woody Plant Issues

• Sudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.– Both diseases have severely impacted nursery industry.

• Pierce’s 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.

Emerging Woody Plant Issues

• Sudden Oak Death (SOD) and bacterial leaf scorch of many woody species threaten both forests and landscapes.– Both diseases have severely impacted nursery industry.

• Pierce’s 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.

DNA-based identification of the soybean cyst nematode assists nursery industry

50 bp

150 bp

350 bp

Uncut Fok I Uncut Fok I Uncut Fok I

SCN CCN SBCN

On-Going Issues of Importance

• Plant Disease Diagnostic Clinics• Horticulture and ANR Agent Training

initiatives.• Developing and refining disease management

recommendations through applied research.• Kentucky Pest News.• Stakeholder training.• Expanded WWW presence

– Websites, blogs, Twitter, listservs, etc.

Questions?