Market Diseases of Apples, Pears, and Quinces: Red Spots
Washington State University HomeWSU AdmissionsWSU CampusesWSU HomeWSU Search Tools*
edge graphic


No photos available for this section.

Postharvest Home Page Apple page Pear page Stone fruit page Postharvest practices page Search the site
Market Diseases of Apples, Pears, and Quinces
Red Spots
Aphids, particularly the green apple aphid, sometimes cause red spots or specks on yellow or green varieties of apple. These may be confused with the red spots caused by San Jose scale, but they differ from them in not having a light-colored center.

Similar-appearing red skin spots are particularly common on Yellow Newtown and may occur on other green or yellow apples on the side that has been exposed to the sun. They consist of narrow reddish halos or bands surrounding mechanical injuries or lenticels. If the lenticels have been ruptured by the growth of the fruits, they are more subject to spotting. Exposure to intense sunlight or penetration of the skin by spray materials also seems to stimulate localized reddening on green varieties or on the green portions of red varieties. Such spots are sometimes mistaken for the effects of San Jose scale, but they can usually be distinguished by their location at lenticels and by the absence of white or light-colored centers. The spots have been known to develop extensively just before harvest on apples that up to that time were free of them.

Go to WSU Home page
WSU Tree Fruit Research and Extension Center | 1100 N. Western Ave. | Wenatchee, WA 98801
Copyright © Washington State University | Disclaimer
Electronic Publishing and Appropriate Use Policy
Monday, September 19, 2005