Apple Scab Alert
PSU EXTENSION EDUCATOR
At the Penn State Fruit Research and Extension Center in Biglerville, the first mature spores were detected on March 24, 2010. The numbers were high for March, being more tpical of those observed by mid-April in most years.
The findings indicate the growing season is three weeks early in southeastern Pennsylvania. Copper spray applications no later than 1/4-inch green tip are highly recommended to manage scab (dormant rate depending on the label). Warm temperatures early in the season will allow large numbers of acospores to mature and be available for infection at the next wetting periods.
More information on the scab life cycle and management strategies may be obtained at http://agsci.psu.edu/tfpg/part2/ AGROSO45-02-02.pdf/view.