WIDESPREAD SCAB and RUST INFECTION PERIOD: A widespread secondary scab infection period occurred May 4-6 from Danville, Roanoke and Lynchburg areas northward through Winchester. In Winchester we recorded 22 hr wetting with a mean temperature of 55° and 2.6 inches of rainfall. This volume of rainfall could have eliminated much of the fungicide residue early enough during the extended wetting to allow some scab and rust infection.
A survey of eleven
NEWA weather stations in Virginia showed volumes of rainfall ranging around 2 to 3 inches
at most recording stations, but Danville had 1.2 in. of rain and 18 hr wetting while
some Albemarle County stations had more than 3 inches, and Rappahannock County
had as much as 5.4 inches and 44 hr wetting. Temperatures were warm enough at
all locations to allow cedar-apple rust infection wherever inoculum is still present. There are still active cedar rust galls at Winchester.
Also, these conditions May 4-6 favored peach scab infection.
FIREBLIGHT UPDATE: Fire
blight conditions developed much as predicted in the May 1 post, with possible
infection conditions May 1, only wetting lacking May 2, then declining risk with cooler temperatures that are predicted to continue through May 13. The remaining susceptible bloom in the Winchester area is
mostly on recently planted trees.
