Accumulated wetting hours (starting April 29, 10 days after petal fall, Apr 19): 165 hr. The threshold for presence of sooty blotch and flyspeck fungi on unprotected fruit is 250 hr. As of May 25 a hygrothermograph in Rappahannock county (Washington, VA) had logged 163 wetting hours, also using the Apr 19 petal fall and Apr 29 start accumulation date.
For practical purposes, cedar-apple rust galls near our AREC have completed their sporulation for this year. Rust lesions are still showing up on apple leaves that were not protected two weeks ago.
Disease management information directed mostly to the Frederick County Virginia tree fruit industry, updated as needed throughout the growing season. Keith Yoder, Virginia Tech Agricultural Research and Extension Center, Winchester, Virginia
About Me
- Keith Yoder
- Professor Emeritus of Plant Pathology, Virginia Tech Ag. Research and Extension Center, Winchester, VA
