Much of the wine grape pathology research we have conducted in Georgia over the last 2-3 years has been associated with resistance management of fungal pathogens such as downy mildew, powdery mildew, Botrytis and others. Alternation or tank-mixing of different fungicide classes is critical for prevention of resistance development. Under the direction of Dr. Walt Mahaffee (USDA; Corvallis, OR), a video has been developed by Dr. Madeline Downing (Clemson University) to fully explain how resistance develops. This short, highly educational video would be worth your review, and there is also a Spanish version available. Links to the video can be found at the Fungicide Resistance Assessment, Mitigation and Extension Network (FRAME) website via the following link:
FRAME website https://framenetworks.wsu.edu/resources/

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.