Factsheet P15: Ink disease

Phytophthora species are pathogenic fungi which attack a wide range of woody plants. The name Ink disease comes from the inky stains it sometimes causes; other names are crown rot, collar rot and Phytophthora root/collar/root/trunk rot.
The most common species involved are P.cactorum, P.cambivora and P.cinnamomi, although several others are also destructive.
Ink disease is a serious fungal disease of trees in many parts of the world with most of the Rosaceae family being susceptible, as well as other species , eg. chestnut in Southern Europe. It has recently become a serious disease of alders in Britain.