IPMP3.0, Oregon State University, Copyright 2000

Biology and Management of Russian Thistle

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Registered Herbicides

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  Russian Thistle

General Description:

  • well branched, rounded bush grows 1/2 - 3 feet high.
  • reddish or purple strips on stems.
  • alternate leaves are long and very thin (needle-like).
  • small inconspicuous flowers develop in upper leaf axils - each flower with a pair of spiny bracts.
  • acts as a host of the sugar beet leafhopper which carries a virus that causes curly-top of sugar beets, "blight" of spinach, tomatoes, and beans.
  • mature plants break off at ground level and tumble, spreading seeds.

Life cycle: annual

  • reproduces by seed, single plant may produce 20,000 to 50,000 seeds.
  • seeds germinate quickly, even after brief and/or limited precipitation.

Habitat/ Crops associated with:

  • primarily associated with drier regions.
  • grows well in dryland cultivation systems \.
  • wheat (east of the Cascades), sugarbeets, potatoes, mint.
  • found in overgrazed rangeland, some irrigated crops, and disturbed waste areas.

Herbicide Control Notes:

  • Goal often not adequate, and higher rates might cause crop injury. Usually emerges too late for effective control with Gramoxone.