Disease	Symptoms	Pathogen/Cause	Management
Cedar-Apple Rust	Smooth, round galls on twigs are up to golf ball size. Their surface may be dimpled like a golf ball.	Gymnosporangium juniperi-virginianae	Prune and destroy galls before the spore horns develop in the spring. In the nursery, apply azoxystrobin, triadimefon, mancozeb, or mancozeb + thiophanate methyl in the summer.
Cedar-Quince Rust	Young leaves and twigs have bright orange spots that look like paint splatters in the spring. These spots darken and become dull orange to rust colored. Slight twig swellings are not obvious except in the spring when their surface is orange with spores. The bark on infected twigs flakes away, growth slows, and twigs die back.	Gymnosporangium clavipes	Prune and destroy infected twigs before the spore horns develop. In the nursery, apply azoxystrobin, triadimefon, mancozeb, or mancozeb + thiophanate methyl in the summer.
Cercospora Blight	In the summer, needles become bronzed, tan, and then gray. Needles of the inner and lower branches are affected first but the disease progresses upward and outward toward the branch tips. Dark fungal fruiting structures form on the surface of infected needles. Microscopic examination of the spores reveals dark, multicelled spores that are longer than they are wide. Affected needles fall, giving the shrub an open, bare appearance.	Cercospora sequoiae var. juniperi	Since the fungus overwinters on the plant, spores are present all year. Infection can occur whenever temperatures are mild and moisture is on the needles. It is best to remove the plant rather than attempt control this disease with fungicides.
Kabatina Twig Blight	Tips of branches die and turn brown or ash gray. These remain on the shrub for many months. Larger branches can be invaded and girdled. On the dead tissue where it meets the still-living wood, small, black, pimple-like fungal fruiting structures form. Microscopic examination reveals oval, colorless spores. See Phomopsis below.	Kabatina juniperi	Prune and destroy infected twigs and branches. It is possible for both Kabatina and Phomopsis twig blight to occur on the same plant. If only Kabatina is present, apply mancozeb. Otherwise, apply mancozeb + thiophanate methyl whenever new growth is present on the shrub.
Phomopsis Twig Blight	Tips of branches die and turn brown or ash-gray. These remain on the shrub for many months. Larger branches can be invaded and girdled. On the dead tissue where it meets the still-living wood, small, black, pimple-like fungal fruiting structures form. Microscopic examination reveals both oval and long, thread-like colorless spores. See Kabatina above.	Phomopsis juniperovora	Prune and destroy infected twigs and branches. It is possible for both Kabatina and Phomopsis twig blight to occur on the same plant. If only Phomopsis is present, apply azoxystrobin, thiophanate methyl. Otherwise, apply mancozeb + thiophanate methyl whenever new growth is present on the shrub.

COMMON NAME	TRADE NAME
azoxystrobin	Heritage
mancozeb	Dithane, Mancozeb, Protect
mancozeb + thiophanate methyl	Duosan, Zyban
triadimefon	Bayleton, Strike
thiophanate methyl	Clearys 3336, Domain FL