From Wayne Porter in Meridian — report of cedar-apple rust on mayhaw.
Mayhaw Spray Alert!
Spring is springing early this year. Mayhaw trees are leading the way in early blooms. Early bloom is the time to start spraying for cedar-apple rust especially if you had it in previous years.
The only home-owner product labeled to control this disease is Spectracide Immunox (myclobutanil). This fungicide needs to be sprayed every 7 to 10 days but stopped 14 days before harvest.
There is no good way to rid yourself of this problem unless the alternate host, cedar trees, are removed from the area. This fungal disease must have two hosts in order to complete its life cycle. Removing one from the equation eliminated the ability of the fungal to continue to live.