Pine Pitch Canker Task Force - Living With Pines Infected With Canker

For Immediate Release
June 14, 1996

For More Information, Call:
Don Owen, Chairman
Pine Pitch Canker Task Force
California Forest Pest Council
(530)224-2494

CARMEL, CALIFORNIA, June 11, 1996 -- Pine Pitch Canker is a fungal disease that infects many species of pine trees. First discovered in California in 1986, its range is spreading and now includes 15 coastal and adjacent inland counties from Mendocino to San Diego. There is no cure and thousands of Monterey and Bishop pine trees have been killed.

The disease causes resinous or pitchy cankers on all woody parts of the tree. One of the first symptoms is the dieback of branch tips in the upper crown. If you have been told or suspect that your trees have pitch canker, what should you do?

The Pine Pitch Canker Task Force, a statewide group working on the disease, recommends the following actions:

1. Have a qualified professional verify the presence of pitch canker. Ask what training or qualifications the person has that enables them to recognize pitch canker. Not all tree care workers may be qualified and other diseases or insects can be responsible for your tree's poor or sickly appearance. Monterey pine is the tree species most likely to contract the disease.

2. If you live in an area where pitch canker is uncommon and your tree is only lightly infected, pruning infected branch tips may help reduce the spread of the disease to other trees, but there is no guarantee of this. If you chose to prune infected branches, do so at a lateral branch which is at least one whorl below (i.e. closer to the trunk of the tree) yellow or red needles and below any infestation of insects within the bark. Diseased and insect-infested branches need to be promptly destroyed or disposed of. Studies have shown that pruning will not stop or reduce future infections in a tree that already has the disease.

3. In areas where pitch canker is common, pruning infected branch tips is not a practical means of reducing disease spread. Because Monterey pines vary in their susceptibility to pitch canker, it is best to wait and see how the disease affects your tree before taking action. Some trees will exhibit few or no symptoms of the disease, while others may become moderately to heavily infected. Highly susceptible trees experience rapid dieback and mortality. For trees that survive the disease, pruning may be needed to reduce hazard or for aesthetic reasons. Insist that tree care workers not use climbing spurs or other equipment that injures the bark since this can create wounds that attract bark beetles and pitch moths and may lead to new infections.

4. A tree does not necessarily need to be removed just because it has pitch canker. However, trees with large dead limbs, a dead top, and trunk cankers are likely to die from the disease. Such trees may present a hazard because dead material can break and fall from the tree and eventually the entire tree could fall. Get expert advice. Hazardous situations need attention. Such trees may also contribute to the buildup of destructive beetles which can attack other trees. The timely removal and disposal of dying trees may help prevent this.

5. Tools and machinery which are used to prune, cut, or chip diseased trees should be cleaned and sterilized before use on uninfected trees or in uninfested areas. Lysol7 or a 10% solution of bleach (1 part household bleach in 9 parts water) are effective sterilants.

6. Disposal of diseased material should be done so as not to spread the disease to uninfested areas. Limbs and small pieces of wood may be chipped and the mulch deposited on site or they may be burned. Any material that is removed from the site should be tightly covered with a tarp during transit and taken to the nearest landfill or designated disposal facility for prompt burial, chipping and composting, or burning.

7. Logs may be split for firewood for local use, but the wood should be seasoned beneath a tightly sealed, clear plastic tarp to prevent the buildup of destructive insects. California Department of Forestry and Fire Protection TREE NOTE #3, Controlling Bark Beetles in Wood Residue and Firewood, provides specific guidelines for firewood tarping. Do not stack pine firewood next to living pine trees or transport it to uninfested areas.

Further information on pine pitch canker disease may be obtained by contacting your local Agricultural Commissioner's office, California Department of Forestry and Fire Protection forester, University of California Cooperative Extension office, or city forester.