CRP

Planning Tips for Noxious Weed Control in CRP Contracts

• Aggressively treat noxious weed infestations prior to seeding or interseeding.
• Map areas of noxious weed infestations. Mark these areas on your plan map. Canada thistle and leafy spurge will recur from roots and seed. Musk and plumeless thistle and knapweeds will recur from seed and overwintering of fall germinated plants.
• Avoid tillage or seeding through noxious weed infestations as much as possible. Tillage may cause germination of seeds and the spread of the infestations to other areas by the transported seed of any of the noxious weeds and the root parts of Canada thistle and leafy spurge.
• Noxious weed control and legumes considerations:
  • Avoid planting legumes in known noxious weed infestations.
  • If it is decided to seed legumes in an infested area, aggressively treat the noxious weed infestations prior to the seeding.
  • Remember, if legumes are planted in a noxious weed infestation, it will make noxious weed control difficult, expensive and labor-intensive.
• Control Options in legumes:
  • Plateau at the labeled rate of up to 12 ounces may be broadcast over legumes:
    • May be effective with musk and plumeless thistle and knapweed in the rosette stage in early spring and in the fall.
    • Apply both in the spring and fall for Canada thistle and leafy spurge.
  • Individual plants of all noxious weeds can be spot treated with the appropriate herbicide for the targeted plant.
  • Individual plants of musk and plumeless thistle and knapweeds could be dug or pulled.
  • Mowing is not a satisfactory control options are:
    • Mowing will prevent seeding of Canada thistle and leafy spurge, but will not kill the plants or prevent the spread of the roots.
    • Mowing will delay seeding of musk and plumeless thistle and knapweeds, but will not stop the plants from further flowering and seed production.
  • Biological control provides supplemental control but is not satisfactory control by itself.