Originally Posted by dward51
Well, thanks to the University of Georgia and Google, we now have a diagnosis......
I have no idea where the cedar that started this is, as I don't have any. Must be in the neighbors yard? According to the info on the web, it requires both plants for the life cycle and can cause total leaf drop in a bad case. Mine looked pretty bad. bummer.......
Apparently the spores can blow up to 1/2 mile from the Red Cedar and infect apple trees. How the heck am I supposed to find the source with that spread?
Yeah that sucks! From what I've read it only occurs East of the Rockies which is why it didn't look like anything I have seen here. Also from reading it is more likely to occur when there is a good amount of moisture. So the large amounts of rain were a contributing factor.
"During rains, after the telial horns absorb water, the teliospores germinate to produce a germ tube (basidium) from each cell. Four basidiospores are produced on each basidium (Fig. 4). At optimum temperatures, basidiospores are produced within 4 hours of the horns absorbing water"
"INFECTION OF APPLE
Before apple can be infected, adequate moisture must be present in a temperature range of 8-24 C (46-75 F) to allow for formation of basidiospores on cedar galls. Then, the basidiospores will infect apple when susceptible leaf and fruit tissues are wet for certain lengths of time at specific temperatures (Table 1 ). Leaves are most susceptible to infection when 4-8 days of age, and fruit are susceptible from tight cluster through bloom."