Etiologic and Cultural Studies of Kabatina juniperi. Andrea Ostrofsky, Former Graduate Research Assistant, Plant Pathology Department, University of Nebraska, Lincoln 68583. Glenn W. Peterson, Plant Pathologist, Rocky Mountain Forest and Range Experiment Station, U.S. Forest Service, Lincoln. Plant Dis. 65:908-910. Accepted for publication 12 March 1981. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/PD-65-908.

Kabatina juniperi caused a branch tip dieback of Juniperus virginiana and J. scopulorum in eastern Nebraska. Infected branch tips became discolored in early spring. Acervuli were present but not yet erumpent in February. Erumpent acervuli were abundant at the base of the dieback in April and May and were present in decreasing numbers through October. Spores germinated on water agar at temperatures from 5 to 32 C; percentage of germination and germ tube lengths after 24 hr of incubation were greatest at 24 C. Spores germinated on water agar at pH values of 3 through 8; percentage of germination and germ tube lengths were greatest at pH 6. Growth in malt extract broth was greatest at 24 C and at pH 5. Light had no effect on spore germination, germ tube length, or growth. Wounding was necessary before inoculation with spores for infection of healthy foliage in the greenhouse. Seedlings became infected when incubated at 100% relative humidity and 16–28 C for 5 days after inoculation. Wounded inoculated seedlings incubated for 24 hr at 100% relative humidity and 24 C also became infected. Scanning electron micrographs showed that the fungus entered foliage through wounds.

Keyword(s): dieback, eastern redcedar, Rocky Mountain juniper.