Virginia Grape Disease Updates

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.

I mistakingly placed Vivando, which does not work on downy mildew, on the downy mildew table. Please strike it out or use the updated version below. 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).

Thank you again for participating in our meeting. Please find two materials from today's presentation. 1) List of short PHI fungicides for late-season diseases (will open a pdf file) 2) Today's presentation (will open a pdf file). Have a good rest of the season, and hope to see you next week at the VVA summer technical meeting!!

This is another reminder about downy mildew. This post is probably more applicable to those of us who are in northern VA. We received several rain events in the past two weeks. Not all of them accounted for downy mildew infection risk events; however, recent warm and humid nighttime weather probably encouraged the downy mildew pathogen to produce spores.  Here are recent downy mildew infection risks based on the NEWA's DMCast. Floyd, VA: Downy mildew risk events on 7/6, 11, and 15. (note: the temperature sensor has been fixed recently, and that's why it shows records from mid-June.) Red Hill, VA and Olympic Lake: If you are in central VA, please check your local weather station. It seems that the numbers vary quite a bit among them. Red Hill: downy mildew risk events on 7/2 and 8. Olympic Lake, downy mildew risk events on 7/2, 6, 8, 11, 12, 15, and 16. Winchester, VA: downy mildew risk events on 7/1, 5, 9, and 13. Protective materials for downy mildew are Ziram (FRAC M3, 21-day

It looks like many of us received some rain in the past few days, and we may see another rain toward the end of this week. Here are recent downy mildew infection risks based on the NEWA's DMCast. Floyd, VA (note: the temperature sensor has been fixed recently, and that's why it shows records from mid-June.) Crozet, VA (note: the precipitation sensor has been fixed recently! We really appreciate the willingness and commitment of the personal weather station owners!) Winchester, VA Protective materials for downy mildew are Ziram (FRAC M3), Captan (FRAC M4), Fixed copper (FRAC M1), Revus or Forum (FRAC 40), or Zampro (FRAC 40 + 45), or Ranman (FRAC 21)). There are increasing cases of Revus resistant downy mildew isolates in VA. Plus, resistance to Ranman is known among downy mildew pathogens of other crops. Make sure to spray before the rain and rotate the FRAC codes! Materials with kick-back activities are Phosphorous acids (Prophyt, Phostrol, etc, FRAC P07), and Ridomil products