Inonotus Root and Butt Rot

Pseudoinonotus dryadeus

50 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.

Yellow-orange conks with droplets (weeping conks) appear at the base of Oregon white oak, indicating decay in large roots and the lower trunk. Pseudoinonotus dryadeus enters through wounds and causes slow internal rot. Avoid wounding with equipment, inspect for decay regularly, and remove unstable trees to prevent windthrow damage.

Irrigation water, especially from sprinklers, should not wet the trunks. Mowing equipment should not injure the roots, crown, or lower trunk.

Quick Reference

Causal Agent
Pseudoinonotus dryadeus
Host Plants
50
Spread
Root-to-root contact; spore dispersal through soil moisture.
Favorable Conditions
Spores released year-round from fruiting bodies; enter through wounded roots ...

Management

Vulnerability Window

Infection year-round through wounds; disease development slow (years). Fruiting bodies visible fall/winter.

What Triggers Infection

Spores released year-round from fruiting bodies; enter through wounded roots or basal wounds. High moisture favors growth.

Cultural Controls

  • Irrigation water, especially from sprinklers, should not wet the trunks.
  • Mowing equipment should not injure the roots, crown, or lower trunk.
  • Inspect trees for decay and/or conks to assess tree stability.
  • Remove trees with extensive decay to avoid damage to surrounding property.
  • Reference Campbell, W.A., and Miller, J.H. 1952.
  • Windthrow of root-rotted oak shade trees.

Host Plants (50)

Quercus acutissima Sawtooth Oak Quercus agrifolia Coast Live Oak Quercus alba (Eastern) White Oak Quercus arizonica Arizona Oak, Arizona White Oak Quercus berberidifolia California Scrub Oak, Scrub Oak, Inland Scrub Oak Quercus bicolor Swamp White Oak Quercus bimundorum Two Worlds Oak, Bimundors Oak Quercus castaneifolia Chestnut-leaved Oak, Chestnutleaf Oak, Persian Oak Quercus cerris Turkey Oak Quercus chrysolepis Canyon Live Oak Quercus coccinea Scarlet Oak Quercus douglasii Blue Oak, California Blue Oak Quercus durata Leather Oak Quercus emoryi Emory Oak, Black Oak, Blackjack Oak Quercus engelmannii Engelmann Oak, Mesa Oak Quercus frainetto Hungarian Oak, Italian Oak Quercus gambelii Gambel Oak, Rocky Mountain White Oak Quercus garryana Oregon White Oak Quercus garryana var. breweri Brewer's Oak Quercus glandulifera Konara Oak Quercus glauca Japanese Blue Oak, Ring-cupped Oak Quercus hypoleucoides Silverleaf Oak, Whiteleaf Oak Quercus ilex Holly, Oak, Holm Oak Quercus ilicifolia Bear Oak Quercus imbricaria Shingle Oak Quercus kelloggii California Black Oak Quercus leana Lea's Oak Quercus lobata Valley Oak, Roble Oak, California White Oak Quercus macrocarpa Bur Oak, Mossycup Oak Quercus marilandica Blackjack Oak, Jack Oak Quercus mongolica Mongolian Oak Quercus montana Mountain Chestnut, Oak, Chestnut, Oak, Rock Chestnust Oak Quercus muehlenbergii Chinkapin Oak, Chinquapin Oak, Yellow Chestnut, Oak Quercus myrsinifolia Chinese Evergreen Oak, Bamboo-leaf Oak Quercus nigra Water Oak, Possum Oak Quercus palustris Pin Oak, Swamp Spanish Oak Quercus petraea Sessile Oak, Durmast Oak, Irish Oak Quercus phellos Willow, Oak Quercus prinoides Dwarf Chinquapin Oak, Dwarf Chestnut, Oak, Scrub Chestnut, Oak Quercus robur English Oak Quercus rubra Northern Red Oak Quercus sadleriana Sadler Oak, Deer Oak Quercus stellata Post Oak Quercus suber Cork Oak Quercus turbinella Scrub Live Oak Quercus undulata Wavyleaved Oak Quercus vaccinifolia Huckleberry, Oak Quercus velutina Black Oak Quercus virginiana Southern Live Oak, Live Oak Quercus wislizeni Interior Live Oak, Chapparal Oak