Calyx end rot

Disease

Calyx end rot

Sclerotinia sclerotiorum (Lib.) de Bary

Distribution: Common to all fruit-growing regions in eastern North America.

Photos

Lesions tend to form to one side of the calyx.

Lesions tend to form to one side of the calyx. Thomas Burr, Cornell Univ.
A

Symptoms begin at the calyx end of the fruit, causing a reddish discoloration at the site of infection. The rot is at first soft, but eventually dries out, turning tan to brown with a red border. Calyx end rot is caused by the "white mold" fungus. Infected fruit have a tendency to drop prematurely.

  • Crops Affected: apples

    Management

    The disease is relatively uncommon and occurs only in seasons when wet and cool conditions occur during bloom and petal fall. It does not spread to other fruit once symptoms appear. Generally, practices employed to control other diseases will keep it from becoming economically damaging.

    Similar Species

    Dry eye rot is caused by the "gray mold" fungus. The two diseases are often confused with each other and may also be confused with blossom end rot infection caused by black rot. Usually, isolation of the pathogen is necessary for positive identification. One field characteristic, however, is that calyx end rot lesions tend to form to one side of the calyx (A), whereas dry eye rot lesions are centered about the calyx (B).

Related Content

About

Resources

Events

  • follow us on youtube
  • follow us on linkedin
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).