Western Gall Rust

Endocronartium harknessii

53 host plants

Last updated

Data Maturity Baseline

This profile contains verified disease data from extension databases. Regional field notes and expert review are in progress.

Lodgepole pine (Pinus contorta) develops branch galls from rust infection. Prune out galls well below the infection site if they occur on branches. If the gall occurs on the trunk, you may retrain a new leader, but tree removal may be necessary for safety. Remove infected trees from pine stands to protect surrounding trees.

Rust fungi often need two different host plants to complete their life cycle, so identifying and managing the alternate host can break the cycle. Remove heavily infected leaves and dispose of them away from the garden. Improve air circulation to speed leaf drying after rain. Fungicide applications are most effective as preventive treatments before symptoms appear; once pustules are visible, the current infection cycle is already underway.

Quick Reference

Causal Agent
Endocronartium harknessii
Host Plants
53
Spread
Wind-dispersed aeciospores from mature galls infect new shoots; no alternate ...
Favorable Conditions
Infection occurs on young, succulent (actively growing) shoots in spring (Apr...

Management

Vulnerability Window

Spring during active shoot elongation (April-June). Young, tender shoots 1-3 years old are most susceptible to initial infection. Galls mature and produce spores 2-3 years post-infection, re-infecting new shoots annually thereafter. (Source: PNW Plant Disease Management Handbook)

What Triggers Infection

Infection occurs on young, succulent (actively growing) shoots in spring (April-June in western Washington). Wet spring conditions favor infection. Once galls form, they persist and annually produce spores without additional weather triggers. (Source: PNW Plant Disease Management Handbook)

Cultural Controls

  • Prune out and destroy galls from infected trees.
  • If the gall occurs on the trunk, it may be possible to prune the tree back and train a new leader to replace the diseased portion.
  • However, it may be necessary to remove the tree for safety's sake.
  • Remove infected trees from pine stands.

Host Plants (53)

Agathis australis Kauri Tāne Mahuta, Kauri Pine Araucaria araucana Monkey Puzzle Tree, Chilean Pine Araucaria bidwillii Bunya Pine Araucaria cunninghamii Hoop Pine, Moreton Bay Pine Araucaria heterophylla Norfolk Island Pine Athrotaxis laxifolia Tasmanian Pencil Pine, Summit Cedar Cephalotaxus harringtonia Japanese Plum Yew, Cow's Tail Pine Glyptostrobus pensilis Chinese Swamp Cypress, Water Pine Water Fir Shui song Microcachrys tetragona Creeping Pine, Creeping Strawberry Pine Pinus albicaulis Whitebark Pine, Scrub Pine, White Pine Pinus aristata Bristlecone Pine, Rocky Mountain Bristlecone Interior Bristlecone Pinus attenuata Knobcone Pine Pinus banksiana Jack Pine, Scrub Pine, Banksian Pine, Hudson Bay Pine Pinus bungeana Lacebark Pine, Whitebark Pine, Baipi Song Pinus canariensis Canary Island Pine Pinus cembra Swiss Stone Pine Pinus contorta Lodgepole Pine Pinus contorta var. contorta Shore Pine Pinus contorta var. latifolia Rocky Mountain Lodgepole Pine Pinus coulteri Coulter Pine, Bigcone Pine Pinus densiflora Japanese Red Pine Pinus edulis Pinyon Pine, Piñón Pine, Two-needle Pinyon Colorado Pinyon Pinus elliottii Slash Pine, Swamp Pine Pinus flexilis Limber Pine, Rocky Mountain White Pine Pinus halepensis Aleppo Pine, Jerusalem Pine Pinus heldreichii Bosnian Pine, Snakeskin Pine Pinus jeffreyi Jeffrey Pine, Western Yellow Pine, Bull Pine Pinus kwangtungensis Kwangtung Pine, Guangdong Pine Pinus lambertiana Sugar Pine Pinus leucodermis Bosnian Pine Pinus monophylla Singleleaf Pinon Pine, One-leaved Pine Pinus monticola Western White Pine Pinus mugo Mugo Pine Pinus mugo var. pumilio Mugo pine, Dwarf Mugo pine Pinus nigra Austrian Pine Pinus parviflora Japanese White Pine Pinus parvifola Pinus parvifola Pinus pinaster Maritime Pine, Cluster Pine, Turpentine Pine Pinus pinea Italian Stone Pine, Umbrella Pine Pinus ponderosa Ponderosa Pine, Western Yellow Pine Pinus pumila Japanese Stone Pine, Dwarf Siberian Pine Pinus radiata Monterey Pine Pinus resinosa Red Pine Pinus sabiniana Gray Pine, Foothill Pine Pinus strobiformis Southwestern White Pine, Mexican White Pine, Chihuahua White Pine Pinus strobus Eastern White Pine Pinus sylvestris Scots Pine, Scotch Pine Pinus thunbergii Japanese Black Pine Pinus virginiana Virginia Pine, Scrub Pine, Jersey Pine Pinus wallichiana Himalayan Pine, Bhutan Pine Pinus yunnanensis Yunnan Pine Sciadopitys verticillata Japanese Umbrella Pine, Umbrella Pine Wollemia nobilis Wollemi Pine