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!)
- 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!
- It is a good idea to tank-mix a phosphorous acid and a protective material, especially your cultivar(s) is sensitive to downy mildew.
- Please do not mix a phosphorous acid product with copper. Our results show a high probability of causing phytotoxicity.