Skip to main content

Disease risks from the 24th

I was out of town, and I did not realize it, but Winchester area received precipitations from a thunderstorm on the night of the 24th.  Since relative humidity was not high (60-70%), leaves did not stay wet for a long time.  (I could not see any measurable precipitation data from Winchester airport.  Maybe some errors of their instrument?)  Thus, there was no grape disease risk associated with the rain.

Looks like we may see some rains next week.  If you have issues with Phomopsis, it may be a good idea to think about protective application of a fungicide such as a mancozeb product.

Also, I uploaded an updated version of the workbook since I received some comments, including one from Dr. Anton Baudoin of our department ;) 
Labels:

Comments

  1. AnonymousMay 2, 2013 at 6:19 AM

    Hi Mizuho
    Picking up a low level (1% vines; ~ 1 damaged bud/shoot per vine)damage of bud
    "boring" and some green shoots cut where shoot and cane intersect. Sprayed carbamyl during wet/rain period (April 30, 10:30am)but still pick up new damage May 2. Please advise: are there visual images of flea beetle and cutworm damage online?

    ReplyDelete
  2. Mizuho NitaMay 3, 2013 at 1:40 PM

    Hi, Please check Doug's page on cutworm.

    http://www.virginiafruit.ento.vt.edu/cutwormsgrape.html

    Also Cornell has a nice page on grape flea beetle.

    http://nysipm.cornell.edu/factsheets/grapes/pests/gfb/gfb.asp

    ReplyDelete

Post a Comment

Please leave your comment here. In order to avoid spam messages, l moderate comments, thus it may take a few hours for your comment to be posted on the page.

Popular posts from this blog

Disease risks from yesterday's rain

Winchester area received precipitations from thunderstorms yesterday.  It started around 3:30PM and lasted until 7:00PM.  The actual amount of precipitation was not high (0.05 in) compared with other northern VA regions where a severe thunderstorm warning was issued, but since the ending part of the thunderstorm hit during the evening, the relative humidity was high (>90%) until 2 AM or so.  Thus, it accounted for 11.5 hours of wetness with the average temperature of 73F.  It was warm and long enough for Phomopsis, black rot, and downy mildew. We are still having chances of rain (40-60%) until Monday.
Post a Comment
Read more

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...
Post a Comment
Read more

EPA is reviewing captan

Captan, which we use extensively to manage downy mildew, Phomopsis, ripe rot, and other grape diseases, is currently under review by the EPA. In order to keep captan as one of our tools to control grape diseases,  please respond to the EPA's registration review page to post your comment  (will open the EPA page). With increasing cases of fungicide resistance with newer products in our region, it is very important for the majority of commercial grape growers located east of the Rockies to keep older multi-site materials such as captan to be used as a backbone of the spray program.  Also, please forward the message to other producers and stakeholders who should respond to the need for this fungicide in our industry. 
Post a Comment
Read more