I appreciate those of you who showed up at the meeting. I’ll try to visit the meeting in the other regions as much as possible. [I do have a research to do, so, I cannot go to every single one of them, though. ;)]
It looks like we will have good weather during next few days, and I think most of you are thinking about pre-bloom or at-bloom applications right now. (Those of you in the Southern VA may be thinking about 1st application after bloom.) Temperature is getting higher (although we had 3-4 days of cool nights), and many of common disease organisms are more active around 60-75F. At pre-bloom, you need to think about Phomopsis, powdery mildew, black rot, and downy mildew control, and for at-bloom or the first application after bloom, you need to add something for Botrytis control. Pre-bloom to 2-3 sprays post-bloom are very critical sprays for disease control in VA growing area.
Rachis and flower part can be infected by these fungi and results in direct problems, and also, in some cases, such as powdery mildew infection on rachis and small berries, it could cause problem later in the season by creating wounds for other microorganisms to come in to cause sour- or bitter-rots. Botrytis infection on flowers may also come back as rots later.
If you have an application due soon, make sure to adjust your spray volume based on the canopy development, and remember that you should not apply sulfur if temperature is85F or above.
Last two nights were cold (lower 40’s) around Winchester. It was not suitable for downy mildew sporulation event. I hope you did not experience any frost injury. Growth stage was about the same as the last time for our Chardonnay and Cabernet sauvignon.