Browsing by Author "Darveaux, Bettina"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Controlling Leafy Spurge and Canada Thistle by Competitive Species
    (1994-06) Biesboer, David D.; Darveaux, Bettina; Koukkari, Willard L.
    A study was performed to assess the use of perennial native grasses in the control of leafy spurge and Canada thistle and also to evaluate the effects of herbicides applied during the fall to leafy spurge crown buds. As part of an integrated vegetation management program, grass treatments containing the native prairie grass little bluestem established well and were effective at reducing the cover of leafy spurge. Paramount to the success of using native grass species is getting adequate grass establishment which necessitates the careful selection of grass species adapted to the specific site conditions. A fall application of the herbicide picloram at 0.5 and 1.0 lb ai/acre was very effective at controlling leafy spurge and may be mediated via the direct absorption of picloram by the elongated crown buds at this time. The report contains an extensive literature review of the biology and weed control efforts of both leafy spurge and Canada thistle.
  • Thumbnail Image
    Item
    Salt Tolerance in Short Stature Grasses
    (Minnesota Department of Transportation, 1998-07) Biesboer, David D.; Neid, Stephanie; Darveaux, Bettina
    In this project, researchers used extensive laboratory, greenhouse, and field studies to determine the relative salt tolerance of select native grasses and forbs used to re-vegetate rights-of-ways within four meters of the pavement edge. The studies found that grasses prove relatively tolerant to salt, but show poor survivability in the field during over-wintering. In contrast, forbs generally are sensitive to salt in their environment. Planting success of monocultures and mixtures of grasses near the pavement edge was poor. Observed percent coverage after two years ranged from about 10 to 20 percent over all tested species. Monitoring of longer established sites also shows that native species do not increase as a stand ages. Soil amendments including gypsum, potash, and potassium nitrate were only minimally effective in alleviating salt stress in sodic soils, although gypsum may have some promise in further field testing. The application of salt during winter salting operations also permanently and negatively impacts soil chemistry, which in concert with other plant stress factors such as soil compaction and infertile roadside soils, will continue to limit the success of establishing desirable vegetation on the inslopes of heavily salted roadways in Minnesota.