Tree Disease No' 5

1
Tree Disease No. 5

• Host species
• A large number of deciduous trees and shrubs as
  well as a few species of conifers
• blue spruce (Picea pungens)
• maples (Acer sp.)
• mountain ash (Sorbus sp.)
• Norway spruce (Picea abies)
• poplars (Populus sp.)
• willows (Salix sp.)

2
Tree Disease No. 5

• Symptoms
• On spruce this disease usually first appears on
  lower branches and progresses up the tree.
  Individual upper branches may show symptoms as
  well.

3
Tree Disease No. 5

• Symptoms
• Needles on infected branches turn purple, then
  brown and die. Diseased needles eventually fall
  off and the infected branch dies.

4
Tree Disease No. 5

• Symptoms
• Infected branches often produce a bluish-white
  sap that oozes somewhere along their length.

5
Tree Disease No. 5

• Signs
• This disease is caused by the fungus
  Leucocytospora kunzei, which survives in infected
  branches. Spores of the fungus are spread by
  wind, rain splash, insects, birds and mammals.