Grape disease risks from the NEWA
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 some issues with the NEWA (I reported to the NEWA, but I am not sure when/if they can fix it…)
Downy mildew risk forecast
We generated the downy mildew forecasted risk based on the past seven days and an 8-day weather forecast. Please click the figure below to enlarge. The model seems to be calling for an incoming rain forecast starting tomorrow in some locations (which was forecasted last week, too). The VA Wine Board and Southern Region Small Fruit Consortium have supported this effort.
AHS AREC Events
Field Day: 9/12/2025 from 9 AM
Target: agrochemical companies, growers, researchers, and other stakeholders
The AHS AREC will hold an apple and grape field day on September 12th. Field tours will start at 9 a.m., and the program will include research updates from Horticulture, Tree Fruit Pathology, Entomology, Viticulture, Grape Pathology, and Enology. No registration is required for this event, but please get in touch with me by Sept 9th if you plan to attend lunch.
Public Open House: 9/13/2025 from 9 AM
Target: Everybody in the community
Please see the flyer below. No registration is required.
Hi Mizo, black rot was very difficult to control this year. still a problem in parts of the vineyard.
did this seem to be a problem in most of Virginia? we had several bouts of fog and heavy dew throughout the season.
Hi David,
The first thing you probably need to do is to make sure it is actually black rot. Since we had favorable conditions for downy mildew for extended periods of time during the months of May and June, many growers experienced infections on clusters. Once young berries are infected, it may resemble black rot symptoms.
Despite of the rains, only a few people reported black rot, so, my guess is the temperature was a bit too cool for black rot outbreaks, but it may also depend on the conditions and history at your location. Please communicate with your local extension agent(s) to get the investigation started.
Best,
Mizuho