Dr. Phil Brannen, Extension Fruit Disease Specialist, Plant Pathology, University of Georgia
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. However, other commodities that might benefit from this testing would be blueberry, blackberry, muscadine, and bunch grapes. 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 from the MDL at the Fungicide resistant test web page. Download the resistant test form and provide as much information as you can.
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: