Kabatina juniperi kills juniper tissue that is at least
one year old. This fungus seems to be unable to attack through healthy
tissue. Instead, it is believed to enter various types of wounds
(e.g., due to insects, mechanical or weather related). Symptoms
are similar to Phomopsis Blight. It takes microscopic inspection
to separate the spores of Kabatina from Phomopsis. However, the
two diseases can be easily separated by where on the plant the canker
is located. If the canker is on the new season's growth it is Phomopsis.
If it is on last year's growth (one year old) then it is Kabatina.
Control is to keep plants healthy and avoid injury as much as possible. Prune out all dead and dying stems/twigs. There are no effective fungicide controls. Resistant varieties are available.
Written by James Schuster, Extension Educator, Horticulture, and reviewed by Bruce Paulsrud, Extension Specialist, Pesticide Applicator Training and Plant Pathology, University of Illinois at Urbana-Champaign.