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Botrytis Sampling in Wine Grapes for Fungicide Resistance Development

Many of the fungicides utilized for Botrytis management are no longer efficacious due to resistance development in this fungus.  Now is a great time to collect Botrytis samples for fungicide-resistance testing.  While the funds last, Botrytis resistance testing is free for wine grape producers in most of the Southeast (Alabama, Arkansas, Georgia, Louisiana, North Carolina, South Carolina, Tennessee, and Virginia) — paid for through a grant from the Southern Region Small Fruit Consortium.  Once funds run out, a pay system will be in place for additional samples.  I would highly encourage you to take advantage of this service.  It is very important that you know the resistance profile for Botrytis at your location — fungicides that should work and those that will not.  Dr. M.D. Ali has provided the following information (see below) to help you with sampling for Botrytis and other pathogens.  If you see ripe rot this year, you should also have that tested as well.  If you have questions or need help, please contact your county agent for additional information.  It would be good to overnight samples to the MDL, and it would likewise be good to communicate with the lab so that they can expect the samples.

From Dr. Ali.

The Plant Molecular Diagnostic Laboratory (MDL), Department of Plant Pathology at the University of Georgia, Tifton is now providing fungicide resistance testing support for several plant pathogens like Botrytis samples from strawberry and wine grapes, Colletotrichum against the strobilurin in strawberry, etc. We accept samples from flowers, leaves, and fruit. You may send cotton swabs with spores from fruit for analysis. The tests currently available, their pricing, a submission form, and submission information are available at the MDL web page at;

Shipping address 

Plant Molecular Diagnostic Lab

Department of Plant Pathology
Tifton, CAES Campus
Plant Science Building
115 Coastal Way
Tifton, GA 31794

Contact information for questions, etc. are as follows:



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About Phil Brannen

Phil Brannen is a Professor in the Plant Pathology Department at the University of Georgia. He attended the University of Georgia for his undergraduate degree in Plant Protection and Pest Management, where he also received an M.S. in Plant Pathology, followed by a Ph.D. in Plant Pathology from Auburn University. He has extensive experience with disease management programs in numerous cropping systems. He serves as the extension fruit pathologist for Georgia – conducting research and technology transfer for multiple fruit commodities. His efforts are directed towards developing IPM practices to solve disease issues and technology transfer of disease-management methods to commercial fruit producers. He also teaches the graduate level Field Pathology Course, the History of Plant Diseases and their Impact on Human Societies Course, team-teaches the IPM Course, coordinates the Viticulture and Enology in the Mediterranean Region Course (Cortona, Italy), and guest lectures in numerous other courses throughout the year.