Issue 4, May 14, 2010
Crabapple Scab Note
Although we have not seen much in the way of apple scab in Champaign/Urbana as yet, it is beginning. Temperatures have been above average and moisture below average, until this past week. The image shows a very early case of scab. This velvety, brown growth is the mycelia and spores of the scab fungus, Venturia inequalis. Keep in mind that the fungus will continue to spread via secondary conidia in wet weather in spring, summer, and fall. There are many sources of crabs with resistance to scab. Refer to issue 2 of this newsletter for details.
--Nancy Pataky
Author:
Nancy Pataky