I guess it is typical of Winchester area. I was monitoring radar regularly for the entire afternoon, watching lines of thunderstorms moving toward northeast over many part of VA; however, our area only received rain from 7 PM to 9 PM or so (~0.6 inches). The estimated leaf wetness period was 6 hours (RH did not stay high due to the wind) with an average temperature of 62F. It was a light infection event for Phomopsis, and also an infection event for downy mildew.
Dr. Mizuho,
I've been using Mancozeb (Manzate Pro-Stick) for DM this season and I have used Ridomil Gold only once (during bloom). I've used Mancozeb one more time after Ridomil but now I should start using Captan because of the PHI for Mancozeb. Is there any real big difference between Captan 80 and Captan 50? I have a lot of Captan 80 to use but I don't have any Captan 50. Do you think I should buy the 50 or can I use the 80? Thank you very much,
Vitor Guimarais
Winemaker and Vineyard Manager at Morais Vineyards, Bealeton VA
Hi Vitor,
Captan 80 WDG and 50 W (or WP) are basically different formulations of captan. The percentages of active ingredient are different, but if you follow the label, the end concentration should be the same. Both are registered for grape, so, it will be just a matter of preference. For example WDG and WP formulation may differ in how they will be dissolved
in water.