Welcome to the Gevens lab!
My research program investigates the ecology of fungus and fungus-like plant pathogens for enhanced and integrated disease management to support commercial agriculture in Wisconsin. We have three main areas of focus: management of Phytophthora species pathogenic on potato and vegetable crops in field and storage, investigating species distribution and occurrence of pathogenic Alternaria affecting potato, and development of integrated disease management programming in potato systems to reduce reliance upon soil fumigation in managing key soilborne diseases. As the University of Wisconsin Extension Potato and Vegetable Pathologist, my program supports vegetable growers by providing research-based recommendations for controlling diseases during production and in storage. My research program directly feeds into my extension work.
Vegetable Crop Update Newsletter

Important update on Blocker fungicide in potato
The situation: In mid-December 2025, AMVAC Chemical Corporation, the manufacturers of the fungicide Blocker (pentachloronitrobenzene, PCNB), decided to stop producing Blocker 4F and 10G. In effect, this concludes production of Blocker for the future. The …

Vegetable Crop Update – Sep 28, 2025
In This Issue: Late blight updates for potato/tomato | Cucurbit downy mildew updates

Vegetable Crop Update – Sep 21, 2025
In This Issue: End of season crop production comments | Potato tuber heat necrosis and hollow heart | Late blight updates for potato/tomato | Cucurbit downy mildew updates | Pink eye of potato
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Articles and Resources

Potato IPM “Back to Basics” video series now available
Instructional videos that can be used as a primer to learn about the basics of potato production, initially focusing on Integrated Pest Management (IPM) basics. Key aspects of insect, disease, and weed IPM programs are …
January 30, 2026
Internal potato tuber defects: Hollow heart and heat necrosis
Hollow heart, depending on its severity, is also called brown center. Hollow heart is characterized by the formation of an irregular cavity in the flesh of the tuber, usually surrounded by dark brown tissues. Heat necrosis is also referred to as internal brown and internal necrosis, which is characterized by small, brown, necrotic lesions or spots inside the vascular ring of the tuber.
September 22, 2025
Pink eye of potato
Pink eye is a disorder of potato tubers that can cause costly storage losses for potato growers and can reduce tuber quality to the point where tubers will be rejected by potato processors. Pink eye not only directly affects tubers, but also makes tubers more susceptible to diseases such as Pythium leak, bacterial soft rot, pink rot, and Fusarium dry rot. These diseases cause additional storage losses and reduction in quality.
September 22, 2025- More Resources posts
Upcoming Events
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Feb03
2026 WPVGA and UW Extension Grower Education Conference - Stevens Point Holiday Inn Hotel & Convention Center Google Maps link
The 2026 Wisconsin Potato and Vegetable Growers Association (WPVGA) and UW Extension Grower Education Conference will be held Tuesday, Feb 3, through Thursday, Feb 5, 2026, at the Holiday Inn Hotel & Convention Center in …
Site Resources
Vegetable Crop Updates
Get the latest information about disease management in vegetable crop production in Wisconsin. To be added to the email listserv and receive this newsletter in your inbox, please contact Amanda Gevens.
Vegetable Disease Resources
Learn more about common vegetable diseases, disease risk prediction tools, and other online and print resources.
Interactive Weather and Risk Charts
View weather data and disease severity values in interactive charts for managing the risk of early blight and late blight of potato from a select set of locations in Wisconsin.
Vegetable Disease Forecasting Network
This map tool helps you visualize disease and insect pressure across Wisconsin based on degree-day models and NOAA meteorological data.
Field Trials
Here you can find reports on our annual fungicide and disease management evaluations.