Notes on Apple Diseases: Russeting

Identification

Russeting is the presence of brown scars of the surface of the fruit. There are many different causes for russeting on fruit, which include frost damage, fungal infections like powdery mildew, yeast and bacteria growth, herbicide drift and phytotoxicity.

Period of activity

Russeting can occur on the fruit throughout the growing season.

Monitoring and Thresholds

There are no thresholds for russeting.

Management notes

There are several causes for russeting and some are controllable, while others are not. As a result, it is often difficult to manage this disease in the orchard. Several important tips for russeting reduction in your orchard are as follows:

  • Select varieties that are less susceptible to russeting (e.g. Empire, Smothee).
  • Maintain an open canopy to increase airflow and decrease drying time for leaves and fruit.
  • Use a preventative fungicide program to manage diseases that cause russeting.
  • When you plant an orchard, locate trees in sunny locations with good air drainage to reduce frost damage.
  • The use of Surround and gibberellins may help to reduce russeting in susceptible cultivars.
  • Avoid the application of pesticides during slow drying conditions or when temperatures exceed 32°C.

Learn more...


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 17 May 2006
Last Reviewed: 17 May 2006