Elytroderma deformans (BC code "DFE") impacts on older plantation pine in the Interior Douglas-fir biogeoclimatic subzone (IDFdk3) are significant and reducing growth on the trees in older plantations that survived the Mountain Pine Beetle epidemic. These stands are a critical part of the mid term timber supply in the wake of the IBM epidemic.

1. Elytroderma Deformans Tour Handout
October 4, 2013
Bill Layton, RPF
Purpose
To bring 100 Mile House professionals together to look at the impacts of Elytroderma deformans
(DFE) in older pine plantations (30+ years) in the 100 Mile House TSA.
Problem
DFE impacts on older plantation pine in the IDFdk3 are significant and reducing growth on the
trees in older plantations that survived the Mountain Pine Beetle epidemic. These stands are a
critical part of the mid term timber supply in the wake of the IBM epidemic.
Scope
DFE is particularly prevalent in the IDFdk3 subzone with severest impacts felt in pine­only
plantations from 70 Mile House through to Gustafsen Lake. In the 70 Mile House area alone there
is between 6,000 and 10,000 hectares severely impacted. There could be as many as
100,000ha of DFE­impacted stands in the 100MH TSA. The SBPS subzones are also impacted
although more so the subzones to the west than the wetter subzone to the east (SBPSmk).

2. Discussion
DFE is significant because it has the ability to grow past the needles and into the cambium of the
tree where it becomes systemic, atrophying the cambium. It can have a major impact on growth
by infecting branches, and even greater impact if the infection reaches the bole.
DFE is common on pine trees older than 20 years within the drier subzones in the 100 Mile
house TSA but most commonly the disease is a simple foliar infection. In the IDFdk3, older pine
plantations have rates as high as 30% of larger trees (layers 1, 2, 3) infected. This “infection
rate” refers to trees that are past the point of being acceptable as well­spaced acceptable crop
trees.
In worst cases (e.g., Hanging Tree on 1000 Road), as many as 1050 pine per hectare or 41%
were discounted as well spaced acceptable. It’s fair to say that many of the accepted crop trees
in these plantations also had DFE infections that were systemic but only on some branches or
part of the crown.
We developed a rule for acceptability whereby trees that had at least 50% healthy crown and
positive leader growth could be considered WSA. It is common for a tree to have a badly infected
lower crown and reasonable looking upper crown. If the leader has stopped growing and the top
is rounded then the infection is considered too great for acceptability.
Elytroderma Facts
From Management Guide for Elytroderma Needle Cast, By Jim Hoffman, US Forest Service
Forest; Health Protection and State Forestry Organizations, May 2004
● Spores mature in small linear black fungal fruiting bodies during mid­ to late­ summer on
needles that were infected the previous year. Alternatively, fruiting bodies can also form
on new needles that emerged from perennial infections on the buds and twigs.
● Spores are disseminated by wind to the current­years needles and germinate if there is
rain or heavy dew.
● After germination the fungus grows rapidly through the needle tissues and into the twigs
without initially killing the needle. Needles die the next spring, turn reddish­brown, develop
fungal fruiting bodies in the summer, and then are shed from the tree during fall rains.
From Hunt, R.S. 1978. Elytroderma Disease of Pines. Forestry Canada, Forest Insect and
Disease Survey, Forest Pest Leaflet No. 27 4p.)
● Once within the shoot, the fungus can grow in both directions, that is, it can keep up to
the host shoot growth and also grow back down the branch, invading other branches and
the tree trunk branches die (Roth, 1959).
● Elytroderma deformans overwinters in three ways: in the cast needles, as new infections

3. in green current needles and in perennial infections in buds and twigs.
● The bright red of the previous year's needles is a good indication of Elytroderma
deformans infection, but experience is necessary to separate this from winter damage,
or other needle cast fungi
● The bright red needles gradually fade to a straw color (Fig) and on lodgepole pine the
needles may become gray.
● The dwarf mistletoe also produces brooms and brown lesions in the inner bark of
lodgepole pine shoots but is readily separated from E. deformans by observing the
parasitic plants.
● Severe infection results in so much needle casting that only the current needles remain
over much of the crown, producing "lion's tail" symptoms.
● Deformities: Needles and shoots are shorter and twigs may be thickened and curved
upward. On some trees there is loss of apical dominance so that lateral buds grow and
the whole tree resembles a broom.
● The fungus damages the tree by decomposing areas of phloem (Waters, 1962), causing
brooms that act as nutrient sinks and causing dwarfing, deformations and vigor loss.
● Severe infection can result in increment loss and predisposition to other
agents.,especially bark beetles and root rots. Thus, it is thus difficult to estimate mortality
directly from this fungus.
● Once perennial (systemic) infection is established, the fungus can spread
vegetatively within the tree so that the impact continues for several years.
● Childs (1968) found that the more severe the crown symptoms, the less the annual
increment, and this deleterious effect increases with time, especially on larger trees.
● Volume reduction may be as great as 50%.
● Disease intensity on lodgepole pine in some areas of the Cariboo and Kootenay Forest
Districts is very high, but studies have not been made to measure its impact (that was in
1978)
● Practical control depends on silvicultural manipulations such as clear cuttings in mature
stands and thinnings to promote vigorous growth in young stands.
● Vigorously growing young stands can outgrow infections in the lower crown (Childs,
1968).
● On valuable trees, pruning out infections, especially brooms, which have potential to
grow into the mainstem, is recommended.

4. (Hanging Tree) The two pine trees in the foreground are roughly the same age. Both have DFE,
one severely:

5. Example of severely infected crown:

6. A badly infected branch

7. Example of fruiting bodies, note the black elliptical shapes on the brown needles:

8. Notice grey coloured needles with fruiting bodies vs. brown needles with none

9. Partial Bibliography
Elytroderma Needle Cast Elytroderma deformans (Weir) Darker
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
References
Boyce, J.S. 1961. Forest Pathology. 3rd ed. McGraw­Hill Co. Pub.
Childs, T.W. 1968. Elytroderma disease of ponderosa pine in the Pacific northwest.
U.S.D.A. For. Serv. Res. Pap. PNW­69.
Hepting, G.H. 1971, Diseases of forest and shade trees of the United States. U.S.D.A. For.
Serv. Handbook No. 386.
Lightle, P.C. 1954. The pathology of Elytroderma deformans on ponderosa pine.
Phytopathology 44: 557­569.
Lightle, P.C. 1955. Experiments on control of Elytroderma needle blight of pines by sprays.
U.S.D.A. For. Serv., Ca. For. & Range Exp. Sta. For. Res. Note No. 92.
Roth, L.F, 1959. Perennial infection of ponderosa pine by Elytroderma deformans. For. Sci.
5: 182­191.
Waters, C.W. 1962, Significance of life history studies of Elytroderma deformans. For. Sci.
8: 250­254.