The new varieties of rhododendrons, which are presented here, are so far resistant to the fungus
Pycnostysanus azaleae and hence are not prone to rhododendron bud blast. The very few
exceptions are mentioned.
In connection with numerous observations and experiments, by myself and others, it can be
assumed that the mentiond fungus infection is not (not at all?) linked to the rhododendron leafhopper Graphocephala fennahi . Nowhere true scientific proof
can be found.