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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Fruit > Apple > Deformed fruit

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Apples > Fruit >Deformed fruit

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  • Image: Apple Scab 1
  • Image: Apple Scab 2
  • Image: Apple Scab 3

Apple Scab
Venturia inaequalis

  • Brown raised corky spots on fruit
  • Severely infected fruit may be deformed and cracked
  • Olive green to brown leaf spots with an irregular or feathered edge, eventually becoming a dark brown to black
  • Infected leaves turn yellow and drop prematurely
  • More information on Apple Scab
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  • Image: Apple Maggot 1
  • Image: Apple Maggot 2
  • Image: Apple Maggot 3

Apple Maggot
Rhagoletis pomonella

  • Adult fly causes punctures by laying eggs under the apple skin, resulting in dimpled and misshapen fruit
  • Larvae tunnel inside fruit resulting in brown streaks and decay
  • Adult fly is black with clear wings and black bands, and a white spot on the back
  • Larvae are legless, white, and 1/3""in length when mature (rarely seen)
  • Adults are active from July until September
  • More information on Apple Maggot
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  • Image: Plum Curculio 1
  • Image: Plum Curculio 2
  • Image: Plum Curculio 3

Plum Curculio
Conotrachelus nenuphar

  • Adult weevils lay eggs in the apples resulting in distinctive crescent shaped tan spots on the skin
  • Fruit can become misshapen and often drop prematurely
  • Adult weevil is small (1/5” in length), dark brown with whitish-gray patches, bumps on the wings, and a distinctive downward-curved snout
  • Mature larvae are yellow-white, ¼" long, and c-shaped (rarely seen)
  • Adults active in early spring (during bloom)
  • More information on Plum Curculio
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  • Image: Apple Curculio 1
  • Image: Apple Curculio 2

Apple Curculio
Anthonomus quadrigibbus

  • Adult weevils makes small punctures by feeding and laying eggs in the apple, resulting in a round tan spot and lumpy/misshapen fruit
  • Adult weevil is reddish brown, ¼ inch long, with four bumps on their backs
  • Weevils are present in early spring
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  • Image: Tarnished Plant Bug 1
  • Image: Tarnished Plant Bug 2

Tarnished Plant Bug
Lygus lineolaris

  • Young fruit can have pitted, deformed fruit when adults insert eggs and feed on them
  • Feeding on flower buds results in loss of flowers
  • Adults are oval shaped, approximately ¼ inch long, brownish in color with streaked yellow and black lines (tarnished appearance), and have a white V-shaped marking on its back
  • Nymphs may be confused with aphids, however, they move fast when disturbed (aphids do not)
  • Adults and nymphs are present early in the season (April-May)
  • More information on Tarnished Plant Bug
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  • Image: Bitter Pit

Bitter Pit

  • Fruit develops dark sunken pits and brown corky tissue within the white apple flesh around the blossom end of the fruit
  • May be caused by calcium deficiency, warm weather and moisture stress during fruit maturity, harvesting too early, heavy pruning, or excessive nitrogen fertilizer application
  • Reduce bitter pit with well-timed irrigation, calcium nitrate foliar sprays before harvest, controlled atmosphere storage, and postharvest waxing
  • More information on Bitter pit

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