Skip to Content

Topsin Use for Dormant Pruning Wounds

I had a question about use of Topsin M for application to pruning wounds (see label below) and how to best apply this fungicide and others for this purpose. In an ideal world, we could have a sprayer designed specifically to go over the top of the cordons after each day of pruning – a banded application. I have seen photos of such from California, and that allows the best application of concentrated fungicide directly to pruning wounds. Painting on the fungicide is time consuming, so I would likely just concentrate a couple of spray nozzles directly at the cordon and go with that – using an airblast or similar sprayer.  You will likely do a better job if you spray down on the cordon/pruning cuts – assuming you can lift the sprayer and use the upper nozzles.  Temperature comes in to play on this, as we are often pruning in really cold conditions.  However, many days will warm up to above 50 degrees, so fungi can become active.  In addition, on sunny days, the plant surfaces actually heat up much more than the surrounding air, so I think fungi are more active than we might think based on air temperature.  The bottom line is that I think Topsin in particular can help to prevent wound-site infections, and I recommend it in our environment to prolong the productivity of vines. I would not use over 30 gallons per acre, as most material will be going on the ground anyway at this time of year; the key is to cover the cuts with the correct amount of fungicide, and less total spray volume will be more efficient than a greater spray volume for this application timeframe.  Follow the Topsin application with a Rally application two weeks later.

Posted in Uncategorized. Bookmark the permalink.

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.