What is Nectria canker, and how do I identify and manage the disease on apple trees?

Apples August 22, 2011 Print Friendly and PDF

Nectria canker is a fungus disease caused by Nectria galligena. It is occasionally found on apple nursery stock shipped into the eastern United States. The economic effects of the disease in the eastern United States are minor. The fungus grows deep into the wood and kills new wound callus as it develops. This annual killing of successive layers of callus results in perennial, target-like, zonate cankers. Eventually the cankers girdle the tree, resulting in a dieback of infected limbs or trees. The cankers are sometimes visible on the trunks of nursery trees at the time of planting, although latent infections can appear later in the season. Nursery trees purchased from the western United States and Europe should be examined carefully for symptoms of the disease. Trees with cankers should be returned to the nursery for replacement or discarded. 

For more information and images, read this article on Nectria Canker of Apple.

Answer provided by A. L. Jones and T. B. Sutton.

Connect with us

  • Facebook


This is where you can find research-based information from America's land-grant universities enabled by eXtension.org



Apple Rootstocks

  • All about understanding and choosing the right rootstock

Apple Cultivars

  • Characteristics, descriptions, and how to choose the best to grow and eat

Establishing an Apple Orchard

  • Buying and planting trees

Managing Apple Trees and Orchards

  • Insects, diseases, wildlife and other challenges

Propagating Apple Rootstocks and Trees

  • Grafting, budding, tissue culture, and all about how rootstocks are developed

Regional Resources

  • Links to apple information specific to your area


This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.