Western juniper has invaded millions of acres of sagebrush rangeland in northeastern California. Mechanical shearing and chipping operations that harvest juniper to produce biomass fuel have the potential to clear significant acreages of juniper dominated rangeland. The shortcomings of shearing operations is that live stumps with low growing limbs below the cutting level re-grow, and many smaller trees that are impractical for the shearing/chipping equipment are left in place, poised to reclaim the site The objectives of this study were to (1) test chemical, mechanical and fire treatments on the control of living juniper stumps and small juniper trees that are left behind following the shearing operation.Juniper shearing was conducted at three locations in Lassen and Modoc counties in 2000 and 2001. Stumps and small tree (<6 ft. tall) were treated with different formulations of imazypic, hexazinone, hand-held brush saws, and a weed propane burner. Stump treatments with imazypic were very effective,resulting in >90% control. Spring applied spray treatments were significantly more effective than treatments applied in fall. Herbicidal treatments were also effective on small juniper trees, particularly hexazinone which resulted in > 90% control. Mechanical sawing and the propane burner also killed the small trees but were approximately three times slower to apply than herbicide treatments and were not practical for use on steep or rocky sites. This research shows that herbicidal applications can enhance the benefit of juniper shearing operations by efficiently and selectively killing the living stumps and small trees that are left behind.
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