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T <br />The consultant's report includes the recommendation that the North Decline area be <br />treated with "Oust" or "Plateau" herbicide in the early spring of 2005 to control <br />cheatgrass, followed several weeks later by interseeding with a seedmix that <br />includes a variety of native warm season grasses, introduced and native cool season <br />grasses, two shrubs, one forb, and three subshrubs. <br />We agree that cheatgrass treatment and remedial seeding is necessary, but we <br />believe that certain modifications to the proposed measures may be warranted. <br />Based on review of relevant literature, observation of field applications, and <br />consultation with weed control professionals, we offer the following observations <br />regarding cheatgrass control: <br />f cheatgrass produces abundant seed crops, providing a soil seedbank that <br />persists for more than one season. Multiple treatments over a one to two year <br />period may offer the best potential for full control, but such repeat treatments <br />may be difficult to implement when the project objectives include both retention <br />of existing desirable vegetation, and interseeding to enhance the existing stand. <br />Q Researchers/weed control practitioners with whom we spoke recommended <br />"Plateau" herbicide over "Oust", and indicated that a fall early post emergent <br />. treatment (6 oz./acre-with methylated seed oil surfactant at 1qt/acre) was likely <br />to be more effective than a spring treatment, with less potential for damage to <br />established non-target grasses and shrubs. The timing is very important; <br />"Plateau" is most effective post emergence, but prior to tillering, while the <br />cheatgrass is still less than 2 inches in height. Recommendations were mixed as <br />to whether the preferred strategy would be a dormant fall seeding later the same <br />fall, or whether it was preferable to wait 1 year for the fall seeding. We spoke <br />with Tim D'Amato, Weed Control Supervisor for Boulder County Open Space <br />(303-678-6110), and Steve Anthony, Garfield County Weed Manager (970-625- <br />86011, regarding general management strategies for cheatgrass control,-and <br />Joel Vollmer with BASF regarding tolerance of specific shrub species to <br />"Plateau" (307-755-5375). <br />A combination of spring and fall herbicide or tillage treatments may be <br />warranted, depending on circumstances. For example, where complete <br />renovation is called for, an approach might include a spring tillage (prior to seed <br />ripeningl, with summer fallow followed by fall "Plateau" treatment shortly after <br />cheatgrass emergence, followed by a late fall seeding. <br />Where desirable to maintain existing perennial vegetation, which is the case for <br />at least most of the North Decline, a spring grazing treatment to minimize spring <br />seed production, followed by a fall early post-emergent application of "Plateau", <br />and a late fall seeding of the entire area may be the best approach. Spot <br />treatment with "Roundup" or a follow-up grazing in the early spring after the fall <br />"Plateau" treatment might be considered, depending on the extent of spring <br />cheatgrass emergence. <br />Please take these recommendations under consideration in developing a <br />cheatgrass control plan. <br />3. A primary objective of the remediation work is to increase the component of warm <br />season grasses, fortis, and sub-shrubs, which are essentially absent from the stand, <br />as well as cool season grasses, which are a relatively minor component. Effective <br />