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Home BYGL Disease Digest April 10, 2008 FLY SPECKS ON APPLE
FLY SPECKS ON APPLE PDF Print E-mail
Gary also reported that a home gardener stopped by the OSU Extension office in Delaware County with a question about tiny black spots on his fruit from last fall.  The problem was diagnosed as fly speck, a disease produced by the fungus Schizathyrium pomi.  Another disease, sooty blotch, produced by the fungus Glosodes pomigena, typically occurs on the same fruit speck.

Sooty blotch is characterized by brown to dull black, sooty blotches with an indefinite outline on the fruit surface.  Blotches may be l/4" in diameter or larger.  Numerous blotches may coalesce to cover practically the entire fruit.  The sooty blotch fungus is restricted to the outer surface of the fruit, and in many cases the blotches can be easily rubbed off.  However, if infection occurs early in the season, you may need to rub or bleach the fruit vigorously to remove it.

Fly speck is characterized by groups of 6 to 50 or more black and shiny round dots that appear on the surface of the fruit.  The dots strongly resemble … fly specks.  The individual specks are clearly separated and can be easily distinguished from sooty blotch.  Like sooty blotch, fly speck infections are superficial; however, they are usually harder to rub off than sooty blotch.  

The following recommendations will help to control these two diseases:
  1. Select an orchard site that always has full sunlight, good air circulation, and good soil (water) drainage.
  2. Prune trees annually to an open center for maximum air circulation.  Both diseases are most prevalent in damp, low, shaded areas in orchards.  Any practice that opens up the trees to greater air movement and promotes faster drying greatly aids in control.
  3. Remove or destroy nearby wild or neglected apple trees.
  4. Backyard growers should remember that the disease is superficial and rarely affects the quality of the fruit.  Removal of the fungus by washing, rubbing, or peeling the fruit results in fruit that is acceptable for cooking or eating fresh.
  5. Especially in commercial plantings, fungicide sprays are important for controlling these diseases.  For the most current fungicide recommendations, commercial growers are referred to Bulletin 506 A2, "Ohio Commercial Tree Fruit Spray Guide."  Backyard growers are referred to Bulletin 780, "Controlling Diseases and Insects in Home Fruit Plantings." These publications can be purchased from your local County Extension office.  

For more information, see:

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Last Updated ( Thursday, 10 April 2008 17:08 )
 

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