Dothistroma
needle blight:essential data |
Disease Name,
Other Names, Crops
Affected Causative Agent, Synonyms,
Description of the Agent Symptoms,
Prevention and Treatment
Other
Comments |
| Disease name |
Dothistroma
needle blight of pines |
| Other Names |
- Dothistroma blight
- Red band disease
|
Causative Agent
|
Dothistroma pini |
| Synonyms |
Scirrhia pini |
| Crops Affected |
Pine trees with Austrian pine
and ponderosa pine being the most important. |
| Description of the Agent |
Dothistroma pini
is a member of the ascomycetes or sac fungi. Strictly it is the anamorph
(asexual or imperfect form) of Scirrhia pini. It is the asexual
spores or conidia of D. pini that are mostly responsible for the
spread of the disease. They are spread during wet weather by splashing
rain. Once the fungus has infected pine needles it can overwinter in them
and may take two years to complete a life cycle. |
| Symptoms |
The disease is first
seen as deep green bands on the needles of the tree. This quickly turn
brown to reddish brown or bright red as the fungus develops spore bodies
that burst through the surface of the needle. Needles lose color towards
the tips and show necrosis 2-3 weeks after green banding is first seen
and begin to drop. The disease does not kill the trees immediately, but
over several years it limits growth, reduces the market value of trees
and can kill trees and contribute to environmental damage such as soil
erosion. |
| Prevention and Treatment |
The fungus can be readily controlled by copper fungicides such as Bordeaux
mixture. Spraying early in the growing season and after new needles
have emerged in mid season can control it. In some circumstances, such
as parks and residential areas, spraying may only be needed every other
year.
Resistant forms of some trees are being developed.
|
| Other Comments |
The most immediate effects
can be seen in pines produced for Christmas trees. Customers will not
by unhealthy or misshapen trees. Longer term damage are most likely in
trees grown for timber use. |