Skip to main content

Disease risks from 6/6-6/8 rains

A series of rain event started around 9:30 AM on June 6th, and continued on until about 2AM on June 8th at Winchester.  Thus we had a wetness event for about 40 hours with an average temperature of lower 60F (~63F).  It was long and warm enough for Phomopsis, black rot, downy mildew, and Botrytis. 

If you are planning for fungicide application to reduce the risk of on-going infection of downy mildew or black rot, please refer to this post, or PMG, or my workbook (PMG and workbook are listed under "Resources").  Looks like chances of rain remain high for next few days across the state.

FYI: Because we have seen downy mildew in our vineyard since last week, we applied Prophyt (a phoshite material) and Ranman (cyazofamid) yesterday morning.  A phosphite material and cyazofamid has a kick-back activity and a protective activity against downy mildew, respectively.  (Note: We did not apply a material for black rot, because it may interfere with some of our experiments.) 

Comments

Popular posts from this blog

Season's Greetings!

I hope you and your family have a good holiday season and a Happy (and safe) New Year! Thanks again for your support of our programs. Here are some recent media highlights. 😉 The link will open a new window. AHS AREC promotional video  that highlights some of our activities. The link did not work... It asks you to log in to VT. I will request the IT people to change the setting, but in a meantime, here's the same video. We also appeared in  the Library of Congress project “Winery Workers of Virginia”. One more announcement: I will be moving this blog to a new location ( ext.grapepathology.org ) early next year. I had to make a change due to the email subscription service, which has been terminated.  You do not need to change your bookmark or your email subscription. The URL will be forwarded to a new site and your email subscription has been moved to a new site already. 

Up-coming meetings and Sentinel Vineyard Report #2

  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 – ...

Recent downy mildew risk events

 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...