Disease risks from yesterday’s rain

Winchester area received rains from 11AM yesterday.  Although rain was over by the evening, the relative humidity stayed high (>90%) until this morning.  Thus, an estimated leaf wetness period was 21 hours with an average temperature of 64F.  It was an infection event for downy mildew, black rot and Phomopsis.  Also, the humid warm night promote downy mildew to sporulate.

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *

© 2025 Virginia Grape Disease Updates - Theme by WPEnjoy · Powered by WordPress