I was walking on campus this morning and noticed a Rocky Mountain Juniper that was showing a mosaic dysfunction pattern around the entire tree.The affected portion is pale yellow in color. The unaffected portion is blue green and appears normal. Some of the discolored portions are brittle and break easy; others seem to have life as they are limber yet. The discoloration seems to affect the last five years of life. The tips are brown to dark brown on about 50% of the affected twigs. My first inclination is juniper blight, perhaps Kabatina tip blight. I am not however seeing fruiting bodies. Any thoughts?

The other Juniperus scopulorum appears healthy. A Juniperus sabina on the other side of campus has similiar symptoms.

Reply to post by Gerald Landby, on February 02, 2001 at 13:08:02:

Perhaps you will find the Silvics site helpful in discovering the underlying problem with the Juniperus scopulorum.
I don't know where you are located, but I imagine that deviations of local environmental factors from those to which the species is adapted may be underlying stresses.
Have you checked closely for mites or other small pests? How about drainage/watering patterns? Are the local temps extreme hi/lo ?

Reply to post by Mark Goodwin, on February 02, 2001 at 13:08:02:

Thanks for the response and the material with the response. I am located in the Northern Rockies. Helana MT. The juniper is on a campus where is it is well-tended. Perhaps too well when one considers its native range. Being winter I will watch and see what happens when then growing season starts. Another possible pathogen I thought of is chemical spray. The campus was sprayed in September to control the fall growth of dandelions and broadleaf plantain. It may have recieved drift from the sprayer. There is 4 more Juniperus scopulorum in the vicinity and they appear fine. The tree is about 22 feet tall. I assume it is about 30 years old as that is how old the dorm is. Thanks again. Gerald