VALLEY DECLARES WAR ON WEEDS

April 10, 2001 12:00 am

By Alice Perry Linker

Observer Staff Writer

The first spring that no weeds grow in the Grande Ronde Valley, the news will be good. For now, its the same old story year after year.

People who work in vegetation management, otherwise known as weed control, believe they are reducing the spread of some weeds, but other species are winning the war.

And it is a war. A couple of years ago, Union County weed manager Gary Dade worked with landowners on Mount Harris to reduce a yellow starthistle invasion. This year, Dades efforts are going to fight diffuse knapweed north of Elgin.

We got a $40,000 grant to work with landowners, he said.

The U.S. Forest Service and private forest landowners fight identical battles. After a winter of low precipitation, Annette Pepin of the La Grande Ranger District is beginning the 2001 battle with some trepidation.

We have a reduced window to treat plants this year, she said. They wont take up the chemical unless theyre growing and vigorous.

Fighting weeds in the national forests is made more difficult by restrictions on aerial spraying of herbicides. The Forest Service has not begun to eradicate the yellow starthistle on its Mount Harris property because the affected areas can be reached only by air. Aerial spraying requires and environmental impact statement, which sometimes takes years to write.

Federal, state and county agencies will meet Thursday to talk about ways they can pool their efforts and funding.

In addition to Dades grant, funds from the Forest Services Demonstration Forest project have been allotted to the weed war.

We hope to broker some funds for private lands, said Rick Wagner of the Oregon Department of Forestry. Our biggest involvement will be to identify landowner opportunity.

According to the 2000-01 budget, the county will spend $135,000 on herbicides this year, but herbicides arent the only weapon in the weed war. Managers stress the importance of a multi-pronged approach and use beetles and other insects to destroy some plants. Once the weeds are treated, grass is planted.

Insects have eaten fairly large patches of yellow starthistle, Dade said.

Where insects have been released, weve seen total eradication, but its a slow, slow process, he

said. Takes up to 15 years.

Diffuse knapweed, which has invaded an area north of Elgin, can be controlled with plowing and reseeding, but when there

is about 100,000 acres

covered in knapweed, plowing doesnt seem

realistic.

Knapweed will spread at a rate of 100 acres a day during the growing season, Dade said.

Pepin and Dade agree on the most dangerous weed in Union County: leafy spurge. It grows like a tree with a main root sinking between 20 and 30 feet into the ground, with roots spreading outward from the main.

Its potentially the worst weed in North America, Dade said.

Herbicides wont always reach the roots but kill only the stems and the tops of the plant.

Were scrambling to find something thats effective against leafy spurge, Pepin said.

Other weeds under the gun:

Perennial pepper weed: In the past three or four years, pepper weed has plagued Ladd Marsh, said marsh manager Dave Larson.

Its a real concern. The Hot Lake property had a bad problem.

Whitetop: The plant is most prevalent in the southern area of the La Grande Ranger District and in Baker County, but Pepin said she believes some reduction has been achieved.

Canadian and musk thistle: Beetles and insects seem to be effective against the thistles, but Larson said he doesnt think it will ever be eliminated.

Education and prevention are the keys to weed management, Dade said. Union County and the cities of La Grande and Union have ordinances governing weed control. If landowners dont control weeds, the governments will spray or dig the plants and bill the landowner.

A public noxious weed clinic, sponsored by several agencies, including the county and the Forest Service, is scheduled for May 12. Final plans have not been announced.