A branch canker caused by species of Fusicoccum, including F. aesculi, causes some mortality, and root and crown rot caused by Phytophthora cinnamomi has destroyed entire stands of the manzanita and prevented its regrowth in patches of infested soil.
Canker caused by Cytospora attacks one of the lower branches first and progressively makes its way higher up the tree.
alternifolia is susceptible to golden canker (Cryptodiaporthe corni), particularly when drought-stressed or heat-stressed.
The Digüeñe is a strict and specific parasite of Nothofagus, mainly Nothofagus obliqua trees and cause canker-like galls on branches from which the fruiting bodies emerge between spring and early summer.
The most serious disease is hypoxylon canker (caused by Entoleuca mammata).
The Winkler vine was damaged by a tractor 'early in its life' and carried a large canker; eventually the vine became infected with the wood rot, Eutypa, causing its death in spring 2008.