![]() Cultural Controlįlail mowing/chopping leaves and brush and removing obvious cankers on the tree may help to control Fabraea leaf spot and is recommended. Other than sanitation, there is no known biological control of Fabraea leaf spot. None known because contact fungicides are necessary for control. Late-maturing varieties may even need fungicide sprays into the early fall to prevent Fabraea from infecting fruit. Where disease pressure is high, however, summer-long fungicide applications (once the pear scab season has passed) will be required, particularly in wet summers. (But EBDC’s have a 77 day Pre-Harvest Interval.) Early season fungicide application(s) for pear scab (as long as EBDC’s or Ziram are included) will prevent initial infection by Fabraea. EBDC fungicides (Manzate, Penncozeb, Dithane) and Ziram give good control. Chemical ControlĬontact/protectant fungicides are necessary to control Fabraea leaf spot. Once primary infection occurs, secondary infection can spread rapidly with rain and wind during the summer, particularly during wet seasons. Infections take about 7 days to become visible. to as little as 8 hours from 68 to 77 degrees F. Length of wetting for infection to occur can range from 12 hours at 50 degrees F. Shoot cankers spread Fabraea from late-April through May (in the Southeast) with more driving rains. Spores are released from leaves with rain from mid-May to July (in the Northeast and Midwest) and result in primary infection on fruit and foliage. Farther south, overwintering is also likely to occur in shoot cankers. ![]() Similar to apple scab, much Fabraea overwinters in leaves on the orchard floor. Severe infections can result in reduced flower bud formation for the following season. Leaf and fruit infections are most notable in the Northeast and Midwest, but in the Southeast, shoot infection can be significant. Fabraea may also infect shoots, again appearing initially as purplish spots, becoming lesions/cankers which may persist into the next growing season. When the infection is severe, defoliation can occur and fruit will become deformed and not sellable and/or drop off the tree. Spots gradually enlarge into brown lesions 1/8 to ¼ inch in diameter. Chemical control using contact fungicides beginning in the spring and continuing into the summer in wet years are necessary to control Fabraea leaf spot.įabraea most noticeably first manifests itself as small, purple-black spots on leaves and fruit.Sanitation by flail mowing leaves and brush may help reduce Fabraea leaf spot spores, however, chemical control is still usually necessary.Fabraea leaf spot infection occurs from spring to summer, and like apple scab, spores are released and spread during periods of rainfall.Infections can result in significant leaf spotting, defoliation, and unmarketable fruit. Fabraea leaf spot is a fungus (Diplocarpon mespili) that infects primarily leaves and fruit of pear and quince.
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