Medusahead Control and Revegetation in Southern Cache County, UT

Final Report for FW00-019

Project Type: Farmer/Rancher
Funds awarded in 2000: $6,414.00
Projected End Date: 12/31/2002
Region: Western
State: Utah
Principal Investigator:
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Project Information


The project has these primary objectives:

1. Test the herbicides Oust and Plateau, which are recommended for controlling medusahead

2. Evaluate two cool-season competitive grass mixtures for their ability to establish and compete with medusahead, a bunchgrass (HyCrest crested wheatgrass) and a rhizomatous grass (Luna pubescent wheatgrass)
3. Try various seeding techniques on steep, rocky hillsides to establish a functional plant community that will keep medusahead from establishing
4. Evaluate forage kochia for its ability to establish and suppress medusahead in treated and untreated plots

Medusahead is an aggressive winter annual grass that is unpalatable to livestock and wildlife and builds up a thick thatch that smothers all other vegetation. This loss of biodiversity, grazing capacity and wildlife habitat, plus the added threat of wildfires, make it important to control small, isolated infestations before they take over large areas.

Five farmers in southern Cache County, Utah, cooperating with the county weed and fire departments, Utah State University and Natural Resources Conservation Service, sought to test herbicides that will control medusahead and assess the wisdom of seeding on the cleared areas with competitive, cool-season grasses.

In September 2000, with the help of the Cache County Fire Department, the five participating farmers burned 75 acres of medusahead. In October, with help from the Cache County Weed Department, the group sprayed 69 acres with either Oust or Plateau herbicides. In late November, 26 acres sprayed with Plateau were seeded with a mixture of either HyCrest crested wheatgrass or Luna pubescent wheatgrass, each mixed with small amounts of western wheatgrass, thickspike wheatgrass and Sherman big bluegrass. The Oust sites had to be rested for a year to allow for the residue to dissipate.

In 2001, forage kochia (a competitive shrub) was seeded to 0.25-acre plots on three farms in late winter. Meanwhile, because of severe spring and summer drought, the 2000 seeding failed, and the seeding planned for 2001 was postponed. Three acres were sprayed for broadleaf weed control and seeded a second time to HyCrest. A band of sheep was used to trample in the seed on a steep slope.

In 2002, given that Plateau failed to control medusahead, the project team planned to spray about 20 acres with Oust. Fifty-five acres were to be seeded in the spring, most of which will require follow-up spraying with Escort to control broadleaf weeds after seeding. The other 21 acres were scheduled for seeding in late fall 2002 or early spring 2003.

The project team evaluated several treatment approaches with medusahead and drew several conclusions and recommendations.

Medusahead is high in silica, which makes it slow to decompose. If a heavy thatch of medusahead builds up, prescribed burning can remove it to provide better soil contact with the herbicide and prepare the land for reseeding. County and city fire departments can help carry out safe prescribed burns.

If the site can be tilled, the best chance for success is to turn the soil over and bury the medusahead seed 4-6 inches deep using a moldboard plow, an offset disc or chisel plow in the fall followed by disc and harrow in early spring.

Oust effectively prevented medusahead and other annual weeds from germinating for 12 to 18 months. Seeding, which works best in the fall, must be delayed 12 to 18 months for the Oust residue to dissipate. On heavily infested areas with little other perennial grass, the recommended rate is 1ounce per acre. Where perennial grasses remain, lower rates may not harm them.

Plateau applied at 6 ounces per acre in the fall gave only partial control, and spring applications were ineffective.

Establishing desirable perennial grasses requires controlling broadleaves. Escort at 0.25 to 0.5 ounces per acre works on most annual weeds, and 2,4-D at 0.5 pounds per acre applied in June during early flowering and again in the fall after frost will suppress field bindweed. The treatments will not permanently injure seedling grasses.

Drought kept the fall 2000 seeding from establishing and prevented spring seeding. One producer, Mike Ralphs, achieved 50% establishment of HyCrest on a steep east-facing slope. He broadcast the seed then fed hay to his sheep on the wet slope to trample the seed in. Other seed covered with a drag, drilled or broadcast failed to establish, but the project team says it will seed Luna and HyCrest when conditions are favorable to establish a productive plant community.

The forage kochia seeding failed at all three sites, with only a few small, fragile seedlings seen.

Grazing management
After the desired plants are established, the farmers will embark on grazing systems that will maintain the stands. They anticipate four kinds of grazing treatments to ensure sustainability: 1) graze early in some years, removing animals before the vegetation bolts and while there is ample moisture for regrowth; 2) restrict grazing during bolting to small areas or subunits by rotating use; 3) in some years defer grazing until after seed ripe; 4) provide complete rest from grazing in some years.

This project has demonstrated and refined procedures for controlling medusahead, an invasive noxious weed, and restoring productive plant communities. It also developed community-wide awareness of the problem, generating cooperative control efforts.

As for environmental benefits, the project reduced the loss of biodiversity, reduced the thatch buildup that could have led to destructive wildfires and the attendant soil erosion and improved wildlife food and habitat.

Agricultural benefits include stemming the loss of forage to medusahead and increasing the abundance of cool-season forages for livestock and wildlife.

Three landowners in fall 2002 began medusahead control projects at their own expense. Two large landowners have included medusahead control in ongoing EQIP cost-share projects. And cost-share funds will be available for 21 other landowners to treat medusahead problems in their respective areas.

To assist these and other efforts, county and city fire departments have agreed to cooperate in safe controlled burns to remove medusahead thatch, and the Cache County Weed Department will assist with herbicide applications. A coordinated resource management committee has been established to oversee medusahead control and reseeding projects in Cache County.

The current label rate for Plateau recommends 8 to 12 ounces per acre, but further research is needed to determine the rate and season of application.

Numerous landowners, government agencies and people in the community have learned about medusahead and efforts to control it.

When an inventory of 10,000 acres found 845 infested by medusahead involving 21 landowners, the Blacksmith Fork Soil Conservation District and the Cache County Farm Bureau scheduled an informational meeting. Thirty landowners attended.

The Utah Department of Agriculture and Food funded a companion small-plot replicated study comparing herbicides, rates, season of application and grass establishment. Publication of the results of this study in scientific journals and as popular articles is likely to bring widespread attention to the problem.

In addition, the Farm Services Agency’s local work group accepted the medusahead project as a local area priority project. An application was made for EQIP cost-share funds in 2000 and again in 2001, and it was funded for $50,000.

A coordinated resource management steering committee was established Nov. 8, 2000, to coordinate control and reseeding projects and to apply for other grants and weed-control funds. Twelve agencies signed a memorandum of understanding and appointed a representative to the committee, including: Cache County Council, Cache County Weed Department, Cache County Fire Department, Cache County Weed Board, Cache County Extension, Blacksmith Fork SCD, Highline Canal Co., USDA-NRCS, USDA-Forest Service, Bear River RC&D, Utah Division of Wildlife Resources and Utah Department of Transportation.

The CRM group persuaded the state to grant a state label for Oust and, in conjunction with the Utah Section of the Society for Range Management, Farm Bureau, Grazing Lands Coalition Initiative, Utah Cattlemen and Utah Woolgrowers, to persuade the Utah Department of Agriculture to develop a strategic plan to receive federal funds for invasive weed control and disburse those funds on a cost-share basis to organized weed management entities.

USU Extension held a field day July 12, 2001, attended by 28 people, showing burning and seed-establishment; two brochures were developed one on medusahead ecology and threat and the other a guide for landowners in controlling medusahead and seeding desirable grasses; and several newspapers and conservation newsletters published articles on the medusahead project.

Five producers were initially involved, but the publicity generated from the project and its cooperative nature among farmers and government agencies have expanded involvement to nearly two dozen farmers.


Participation Summary

Research Outcomes

No research outcomes
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.