Bitter pit and cork spot

Disease

Bitter pit and cork spot

Physiological disorder

Distribution: Widespread

Photos

Individual lesions are dry and do not extend deep into the fruit.

Individual lesions are dry and do not extend deep into the fruit. William Turechek, USDA-ARS
B

Small, green to purplish to light brown, slightly sunken lesions appear on the surface of mature fruit (A). Individual lesions on the fruit surface are dry and do not extend deep into the fruit (B); however, cutting into the fruit can reveal numerous internal lesions. Bitter pit usually develops in storage and is most severe at the calyx end. A similar calcium-related disorder that occurs only on d'Anjou pears is named cork spot.

  • Crops Affected: apples, pears

    Management

    This is a physiological disorder associated with calcium deficiency in apple fruit. It is common on the varieties Cortland, Gravenstein, Honeycrisp, Northern Spy, and York. Losses can be minimized by avoiding excessive tree vigor (because shoots compete with fruit for calcium) and applying calcium sprays during summer.

    Similar Species

    On apple, symptoms can be confused with other calcium-related physiological disorders such as Jonathan spot and the disease Brooks fruit spot.

About

Resources

Events

Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).