Rusts - (several species)
TYPE
HOSTS
DESCRIPTION

Gymnosporangium Rusts - (Apple-cedar rust, Juniper-hawthorn Rust)
Gymnosporangium Rust
Edward L. Barnard, Florida Dept. of Ag & Consumer Sciences, www.ipmimages.org
cedar apple rust
Helen Atthowe, Missoula County Extension

Rust occurs anywhere that perennial hosts (juniper, cedar, etc.) grow near their deciduous hosts. Orange leaf spots, defoliation and fruit and twig deformities. Juniper infections appear as swellings on deciduous host or galls on twigs, these form gelatinous orange fruiting bodies in the spring.
Western Gall Rusts - Endocronartium harknessii
Western Gall Rust
Helen Atthowe, University of Montana

gall
Fred Baker, Utah State University, www.ipmimages.org
Lodgepole, mugo, Scots, Austrian and ponderosa pine. Rough, globular galls on trunks or branches of pines. When the fungus is fruiting the galls are yellow or orange.
White Pine Blister Rust - Cronartium ribicola
White Pine Blister Rust
John W. Schwandt, USDA Forest Service, www.ipmimages.org

The fungus attacks all five needle pines. Rough elongated cankers develop on trunks. Orange spore masses burst through cankered bark. Pitch flows around the canker wound.
Rose Rust -
Phragmidium mucronatum



Baldo Villegas - sactorose@yahoo.com

Rose. Orange spots are present on leaves. Spots on canes are orange, but become black in the fall and winter.


CONTROLS: Optimal temperatures for rust infections are 64-70° F. High temperatures (>85° F.) and dry weather discourage rust disease.

Cultural: Irrigate early enough in the day so that plant surfaces have time to dry before the cooler temperatures of evening. Keep irrigation off of leaves, branches, and trunk.

Maintain plants for good air circulation. In the case of vegetables, plant rows to run with the prevailing winds.

Use resistant cultivars, where available (see specific vegetable entries).

Mineral: Sulfur sprays can be effective if sprayed preventatively when rust infection periods occur.


Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006