Disease risks from yesterday’s rain

Winchester area received rain from 4:40 AM and a series of rain went through our area until 2:20 PM (0.11 in), the relative humidity was high (>90%) until 4:40 PM, thus, we had about 12 hours of wet event with the average temperature of ~63F.  It was warm and long enough for Phomopsis, Black Rot, and Downy Mildew.

We are also expecting more rain during the weekend.  The chance of precipitation (by thunderstorms) is 30-40% throughout the state during Saturday and Sunday.  I think most of us are still in the critical period for berry infection by black rot, downy mildew, and powdery mildew (bloom to 4-5 weeks after bloom).  Please check your spray program and local weather to make an adjustment, if necessary.

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