Cedar apple rust and what it is
Have you noticed the nasty orange blobs forming on your junipers? This is a disease called cedar apple rust that is host specific to Junipers and crabapple trees. It is a huge problem in this area because both of these plants are arguably the most commonly planted trees due to their hardiness to our soil and climate. The article below from K-State will give you some info on ID and treatment. Let me know if you have any questions.
"Symptoms of cedar-apple rust on flowering crabapple and apple are easily identified. In late spring or early summer, bright, yellow-orange spots approximately 1/8 to 1/4 inch in diameter form on the upper surface of leaves. These spots gradually enlarge and turn orange.
Small black fruiting structures (pycnia) of the fungus form in the center of the lesion. An orange gelatinous matrix often may be seen oozing from the fruiting structures during wet weather. Eventually, an orange, cup-like fungal structure (aecium) forms on the bottom surface of the leaf directly beneath the lesion on the upper surface. This structure has small, tube-like projections in which dusty-orange spores of the fungus are produced. Symptoms of cedar-hawthorn rust are similar to those described. Cedar-quince rust does not affect leaves, but does occur on young twigs and fruit.
Leaves with numerous spots drop during the summer. Premature defoliation weakens the tree and reduces fruit set and yield the following year. Trees with severe defoliation also are susceptible to other diseases. Cedar-apple and cedar-quince rust may cause fruit lesions. Diseased fruits develop deep pits or become distorted and usually drop before harvest.
Both cedar-apple and cedar-hawthorn rusts produce reddish-brown galls on the twigs of juniper. These woody galls usually are ½ to 2 inches in diameter. In early April, galls swell and produce orange, one-inch long, gelatinous tendrils. The tendrils remain on the galls through May. Trees with numerous galls are easily identified by their bright orange cast during rainy weather. The galls of cedar-apple rust last only one season; the spent galls dry and fall from the tree during the summer months. The galls of cedar-hawthorn may last for several years. The cedar-quince rust produces perennial, cigar-shaped galls on the twigs and branches of juniper. For more details concerning the disease on juniper see the fact sheet at:" – KState research and extension 9/1/06