Here are snapshots from the last week, showing the number of days with the risk of each disease: Ph = Phomopsis, PW = Powdery mildew, BR = Black rot, and DM = Downy mildew. N/A means there is no data or some issues with the NEWA. This year, we have been using a different downy mildew model due to inconsistency with the NEWA model. This model uses the past five days of weather to estimate spore production and the next seven-day forecast to estimate the infection risk.

You can ignore BR and Ph at this point of the season because clusters are no longer susceptible to the infection. We will focus mainly on downy mildew. Despite some rains going through the state, the risk is still low, based on the last five days of nighttime conditions. However, we are expecting (hopefully) a rainy week. I would protect your vines from downy mildew (and Botrytis, if your vines are in veraison).

For more details on veraison grape disease management, please see the slides below.

Captan registration – public comments are due 7/31/2024!

As we discussed at the VVA meeting, the EPA is reevaluating the uses of Captan, Ziram, Ferbam, Thiram, and Acephate. They indicate they want to cancel all uses for some or all of these materials. To counterbalance this initiative, the EPA is now offering a comment period for the public. As many of you know, captan is used as one of the backbone materials, especially after Mancozeb’s 66-day PHI kicks in. (reminder: you are most likely approaching the 66-day limit!) Please provide your feedback on the utility of these materials for local and national grape growers.

Go to this website:

https://www.federalregister.gov/documents/2024/04/30/2024-09181/pesticide-registration-review-proposed-decisions-for-several-pesticides-notice-of-availability

The top icon on the left is a link to “Submit a Public Comment” (or better yet, the LINK to the comment page.)

What they are looking for in the public comments are

• Quick background from you and of the industry you are in
• The use scenarios for the product
• The importance of the product for your operation(s)
• Do we have any alternatives? Is it practical?
• Cost benefit analysis (or simple cost comparison to alternatives)
• What would happen if you lose the product?

These are examples for comments:

Regulations.gov

https://www.regulations.gov/comment/EPA-HQ-OPP-2015-0567-0062

I will develop my own comments, but please spend some time voicing your opinions on captan and ziram!