Vine status
I was hoping to see some progress by now, but since the temperature has been relatively low (or maybe normal for this time of the year), vines have been relatively slow. I saw some movements with hybrids and table grapes. Let’s hope that we will get some secondary shoots coming up. If you have not had a chance, please see my previous post about disease management after the frost event.
Disease risks 4/22-4/29/2026
NEWA is an Agricultural Weather Station Network, and we are part of the team. Here is a snapshot 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 issues with the NEWA. I am waiting to hear back from the weather station company about fixing the one in Stafford.
There are some locations with 2-3 days of downy mildew risk events in the last seven days.
Downy mildew forecast
It looks like the model is calling for downy mildew infection events next week. As usual, prevention is the best approach. Please refer to my previous post about downy mildew management.
The downy mildew forecasting effort is supported by the Virginia Wine Board.
Update on Mancozeb: It will be available for use.
Please see the write-up from Dr. Katie Gold at Cornell University below. In this article, she announced a new research project on mancozeb residue and alternative options. The key takeaway is that the EPA is unlikely to make any changes to the Mancozeb label in the near future. Her estimate for the change is around 2030. The label language will depend on the results of her study and other factors. I am hopeful that the label changes won’t eliminate mancozeb altogether, as the EPA originally proposed. It is such a vital component of our disease management, especially in the East of the Rockies.
Update on Mancozeb (Dr. Katie Gold, Cornell Univ.)
Update on Isomate GRB Z: Section 18 approved, and it will be available soon.
A very effective pheromone-based treatment against the grape root borer, Isomate GRB Z, will be available again this year. It should arrive at distributors in mid-May or so. Please contact local Nutrien or Helena for more information. You will see its label at the end of this post.
Don’t let this happen to your vineyard!
