Laserfiche WebLink
controlling the target weed. Many scenarios are possible related to the reclamation process. The <br />following are only examples as unique situations seem to frequently arise requiring deviation from <br />the generic plans. Special consideration needs to be given to the potential impacts to diversity <br />and stand establishment from both the herbicide and the weeds. <br />Scenario example #1: A short term disturbance is resloped and prepared for reseeding in mid- <br />summer. Some native plants that survived in the topsoil have begun to reestablish. Later in the <br />fall cheatgrass is also observed in sufficient density to be a concern for reclamation. <br />In this example we would attempt to preserve the existing vegetation while controlling the <br />cheatgrass to the best of our ability. Cheatgrass is a winter annual or annual. Post - emergent <br />treatment with glyphosate (Roundup) would be advisable. We delay reseeding and spray just <br />prior to freeze up. Cheatgrass is typically the last plant to go dormant and first to break <br />dormancy. Delayed spraying allows the maximum emergence of cheatgrass seedlings while <br />allowing other desirable species to go dormant reducing their susceptibility to the herbicide. <br />Reseeding occurs late in the fall to early winter following the plant -back intervals on the herbicide <br />product label. Under this scenario one can expect additional sprouting of cheatgrass in the spring <br />but the reduction in cheatgrass stand density will hopefully be sufficient to aid the establishment <br />of the desired species. <br />Subsequent spraying may be necessary for longer term control of cheatgrass to allow time for the <br />perennial species to mature. Imazapic (Plateau) or sulfometuron methyl + chlorsulfuron <br />(Landmark XP) can be sprayed in the fall one or two years following seeding. The exact time <br />between seeding and spraying is dependent of the seedling's stage of development. Frequently <br />summer droughts put seedlings into a dormancy and delays growth. Either of these herbicide <br />may also decrease diversity since the tolerance for these chemicals is not known for all the <br />occurring species and some could be especially sensitive. <br />Imazapic has received much publicity for its ability to control cheatgrass. However, there are <br />several drawbacks which warrant caution in its use. First, it is recommended to wait one growing <br />season after application before seeding. The label discusses seeding near the time of application <br />but local experience has documented several failures using this method. Second, imazapic <br />needs to be applied to bare soils for pre- emergent weed control. Cheatgrass can leave a <br />substantial duff layer resulting in reduced control. <br />Landmark XP is not currently registered for use on rangeland. Therefore its use is currently <br />limited due to label restrictions. <br />Scenario example #2: A very dense stand of Russian thistle seedlings (1 to 2 inches in height) <br />are observed on a reclaimed site in its second year of growth. Desirable plants include the <br />normal grasses plus alfalfa, milkvetch, and several shrub species. <br />Minor Revision #157 (10/2013) V -70 <br />