Cedar-apple rust is a fungal disease that requires both a Rosaceaous host (such as apple) and a cedar host (such as Eastern red cedar). On apples, bright orange-yellow lesions are first visible after ...

This gall formed by the cedar-apple rust pathogen is exuding tentacle-shaped structures, called telial horns, which produce spores that will infect apple trees and other hosts in the rose family. The ...