Yesterday, Winchester had a drizzle during 3-4am with an average temperature of 58F. It was not a major rain event; however, the relative humidity was almost 100% until 10am. In addition, we had a rain event from 8:30 to 9:30am with an average temperature of 55F. A combined precipitation was 0.08 inches.
If you separate these events, it was not enough for Phomopsis to cause disease. However, since the relative humidity was high during the night, I tend to think it was a continuous event. If we combine both rain events, it was enough for a moderate infection (15-25% severity) for Phomopsis. Considering how wet it has been, ascospore discharge of powdery mildew was probably initiated with these rains (especially after 3 am one) whether you combine events or not. (but the morning rain might have washed spores off from leaves… a wishful thining ;))
I was running 10K for Apple blossom festival during the morning rain. It brought temperature down and was nice for me, and after the rain, we had a really nice Saturday afternoon to enjoy the parade.
We are having a yet another rainy day. It started around 8am and still going as of 10am. A radar image is showing green around Winchester…