Virginia Grape Disease Updates

  I think many readers of this blog subscribe to Tony’s viticulture note, but just in case, here is some information that you may be interested in. The second Sentinel Vineyards Report is out now.  The report is attached at the end of this post.  Make sure to subscribe to Dr. Beth Chang’s Blog here:  https://sites.google.com/vt.edu/vtenology/home Two upcoming meetings: New Grower Workshop 4 November 2021 at Winchester VA Team taught sessions for new grape growers and those considering developing a wine grape vineyard in the Mid-Atlantic.  Registration is required ( and the deadline is this Friday! ). Please click the link below.   https://register.ext.vt.edu/search/publicCourseSearchDetails.do?method=load&courseId=1600122 Virginia Wineries Association Annual Meeting November 15 & 16, 2021 Hybrid event: in-person (Richmond, VA) and remote virtual options The technical session theme on Day 2 is “Wine Stabilization – ...

 It seems that several rain events have happened over the course of the past two weeks or so. Here is a summary of recent downy mildew risk events, based on the NEWA stations and DMCast. Bristol, VA Fifteen days with potential DM infection event(s) since Sept 1. The latest event happened last Sunday. Floyd, VA Eleven days with potential DM infection event(s) since Sept 1. The last event happened last Friday. Charles City, VA Twelve days with potential DM infection event(s) since Sept 1. The latest event happened yesterday. Central VA Since there was a wide variation among stations, I am listing several around Central VA. Tyro, VA Nine days with potential DM infection event(s) since Sept 1. The latest event happened yesterday. Red Hill and Crozet, VA Only one day with potential DM infection event(s) since Sept 1. Olympic Lake Thirteen days with potential DM infection event(s) since Sept 1. The latest event happened last Sunday. Washington, VA Eight days with potential DM infection e...

  Please find a link below to download a new disease management guide for non-bearing grapes. As with the other VCE guides, you need to click on the “Preview” icon, which will open a new window, then click on the “Download” icon to obtain a pdf copy. https://resources.ext.vt.edu/contentdetail?contentid=3226&quantity=1&productprice=0&contentname=Fungicide%20Spray%20Guidelines%20for%20Non-bearing%20Vineyards Also, I updated a list of fungicides that you can obtain from home garden centers. I saw several new products, but unfortunately, many of them do not list grapes on their label, so, the list is identical to the old version. If you know of other products that can be used for home gardens, please let me know. Home-garden-fungicides-2021 Download

  In preparation for hurricane Ida, here is some information that you may find useful (This is a repeat of the previous post, but I received some emails asking for them.) 1)  List of short PHI fungicides for late-season diseases (will open a pdf file) 2)  Updated presentation from the last virtual field day (will open a pdf file). Recent downy mildew risks Many of us have been experiencing more rains lately than the past several months, here are a number of days with downy mildew risk events in the past two weeks based on the NEWA’s DMCast. Many of these rains have been sporadic in terms of area and time it covered, so, use these numbers as a guide. Bristol: 14 days (latest was on 8/30) Floyd: 9 days (latest was on 8/29) Charles City: 14 days (latest was on 8/30) Tyro: 7 days (latest was on 8/30) Red Hill: 5 days (latest was on 8/29) Washington: 8 days (latest was on 8/29) Winchester: 9 days(latest was on 8/29) It is probably a good idea to protect your vines against down...

Recent rains and more rains in the forecast made me think of downy mildew. Let's take a look at what the NEWA DMCast model says about downy mildew risks from the past two weeks. Westfield, NC (South of Stuart, VA) There were six DM risk events, including one that happened today.  (Note: we have a new weather station in Bristol. You can check the weather data, but the DMCast model is not working yet. I notified the NEWA about the lack of DMCast outputs.) Floyd, VA There were four days with downy mildew risk event(s) since the beginning of the month. Red Hill There were four days with downy mildew risk event(s) since the beginning of the month. Washington, VA There were nine days with downy mildew risk event(s) since the beginning of the month. Winchester, VA There were five days with downy mildew risk event(s) since the beginning of the month. It looks like there were more downy mildew risk events as we move northwards. Also, recent warm and humid nights can promote the downy mildew...

Thanks again to those of you who made it to the meeting. It was nice to have a face-to-face meeting after the whole thing we are in together. Here's my handout from today's meeting.  It will open a new window with a pdf file.