North Dakota State University
NDSU Extension Service


Survey of Weeds in North Dakota - 2000

ER-83, May 2003
R. K. Zollinger, NDSU Extension Weed Specialist


Table 81. Adams county weed infestations based on 8 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Green foxtail 87.5 55.0 62.9 10.2 11.7 <0.1 2.9 108.0
Wild oat 75.0 35.0 46.7 7.4 9.9 <0.1 3.3 77.3
Kochia 62.5 26.3 42.0 5.7 9.0 <0.1 3.4 60.3
Russian thistle 62.5 22.5 36.0 3.2 5.2 <0.1 2.0 50.9
Wild buckwheat 50.0 20.0 40.0 3.9 7.8 <0.1 2.5 45.8
Sunflower 50.0 11.3 22.5 1.6 3.2 <0.1 1.8 31.7
Field bindweed 37.5 10.0 26.7 2.6 6.8 <0.1 4.0 28.5
Common cocklebur 37.5 7.5 20.0 1.7 4.7 <0.1 3.3 24.1
Prairie wild rose 37.5 6.3 16.7 0.8 2.2 <0.1 1.3 20.6
Sweetclover 25.0 5.0 20.0 0.7 2.7 <0.1 1.5 14.9
Pigweed species 25.0 5.0 20.0 0.5 2.2 <0.1 1.0 14.6
Volunteer cereal 12.5 7.5 60.0 1.1 8.6 <0.1 2.0 14.2
Common ragweed 25.0 3.8 15.0 0.7 2.7 <0.1 2.0 13.7
Perennial sowthistle 12.5 5.0 40.0 0.9 7.5 <0.1 2.0 11.4
Downy brome 12.5 2.5 20.0 0.7 5.4 <0.1 4.0 8.2
Quackgrass 12.5 1.3 10.0 0.5 4.3 <0.1 4.0 6.7
Common milkweed 12.5 1.3 10.0 0.1 1.1 <0.1 1.0 5.7
Weed free 12.5 1.3 10.0 - - - - -


Table 82. Barnes county weed infestations based on 25 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Yellow foxtail 32.0 14.0 43.8 8.7 27.0 <0.1 7.6 44.9
Green foxtail 40.0 15.6 39.0 4.2 10.4 <0.1 4.2 38.7
Kochia 44.0 15.6 35.5 3.5 7.9 <0.1 2.9 38.4
Canada thistle 40.0 7.2 18.0 1.3 3.3 <0.1 1.9 23.6
Sunflower 24.0 5.6 23.3 1.0 4.3 <0.1 2.0 16.0
Wild buckwheat 24.0 4.8 20.0 1.1 4.7 <0.1 2.5 15.4
Common milkweed 28.0 4.0 14.3 0.5 1.7 <0.1 1.1 14.4
Common ragweed 20.0 4.8 24.0 0.8 3.9 <0.1 2.0 13.3
Wild oat 16.0 4.0 25.0 1.0 6.2 <0.1 3.3 11.6
Pigweed species 16.0 4.0 25.0 0.7 4.6 <0.1 2.3 11.0
Common cocklebur 12.0 4.4 36.7 0.6 5.4 <0.1 2.0 9.9
Volunteer cereal 12.0 2.4 20.0 0.3 2.9 <0.1 1.7 7.2
Venice mallow 4.0 2.4 60.0 1.2 31.2 <0.1 9.0 6.6
Hairy nightshade 8.0 2.0 25.0 0.3 4.3 <0.1 2.0 5.5
Biennial wormwood 8.0 2.0 25.0 0.3 3.8 <0.1 1.5 5.4
Field bindweed 8.0 1.2 15.0 0.2 2.2 <0.1 1.5 4.3
Common lambsquarters 8.0 1.2 15.0 0.1 1.6 <0.1 1.0 4.2
Yellow nutsedge 4.0 1.2 30.0 0.3 6.5 <0.1 3.0 3.1
Marshelder 4.0 1.2 30.0 0.2 4.3 <0.1 2.0 2.9
Barnyardgrass 4.0 0.8 20.0 0.1 3.2 <0.1 2.0 2.4
Flixweed/Tansy mustard 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.8
Prickly lettuce 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.8
Annual smartweed 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.8
Common mallow 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.8
Quackgrass 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.8
Weed free 100.0 38.0 38.0 - - - - -


 
Table 83. Benson county weed infestations based on 16 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Green foxtail 87.5 41.3 47.1 40.8 46.6 0.8 26.6 165.5
Yellow foxtail 81.3 33.1 40.8 35.5 43.7 2.3 20.0 143.1
Canada thistle 75.0 23.1 30.8 9.4 12.5 <0.1 6.3 69.9
Pigweed species 68.8 20.6 30.0 4.6 6.8 <0.1 3.0 54.4
Wild buckwheat 56.3 20.6 36.7 5.4 9.6 <0.1 2.9 51.9
Common ragweed 37.5 15.6 41.7 4.6 12.4 <0.1 3.0 39.0
Kochia 43.8 7.5 17.1 4.5 10.3 0.1 3.4 32.6
Canola 18.8 4.4 23.3 8.3 44.5 0.1 12.3 30.1
Volunteer cereal 18.8 8.1 43.3 4.0 21.2 <0.1 9.3 23.6
Flixweed/Tansy mustard 25.0 8.8 35.0 1.6 6.5 <0.1 3.0 20.9
Prickly lettuce 31.3 6.9 22.0 1.3 4.3 <0.1 2.2 20.4
Wild oat 31.3 5.0 16.0 1.3 4.1 0.8 8.0 18.4
Field pennycress 18.8 5.0 26.7 1.7 9.3 <0.1 5.3 15.3
Quackgrass 18.8 3.8 20.0 0.9 4.7 <0.1 2.7 12.0
Eastern black nightshade 18.8 2.5 13.3 0.7 3.9 <0.1 3.3 10.5
Russian thistle 18.8 2.5 13.3 0.5 2.5 <0.1 2.0 9.8
Common milkweed 12.5 1.3 10.0 0.7 5.4 <0.1 5.0 7.0
Common mallow 12.5 1.9 15.0 0.4 3.2 <0.1 2.5 7.0
Dandelion 6.3 1.9 30.0 0.5 7.5 <0.1 4.0 5.1
Marshelder 6.3 1.3 20.0 0.1 2.2 <0.1 1.0 3.6
Wild mustard 6.3 1.3 20.0 0.1 2.2 <0.1 1.0 3.6
Common lambsquarters 6.3 0.6 10.0 0.1 2.2 <0.1 2.0 3.0
Cutleaf nightshade 6.3 0.6 10.0 0.1 2.2 <0.1 2.0 3.0
Prairie wild rose 6.3 0.6 10.0 0.1 1.1 <0.1 1.0 2.9
Flax 6.3 0.6 10.0 0.1 1.1 <0.1 1.0 2.9
Dry bean 6.3 0.6 10.0 0.1 1.1 <0.1 1.0 2.9
Weed free 18.8 2.5 13.3 - - - - -


Table 84. Billings county weed infestations based on 4 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Wild buckwheat 75.0 35.0 46.7 5.1 6.8 <0.1 2.3 71.9
Green foxtail 75.0 10.0 13.3 14.3 19.0 0.5 4.3 68.3
Wild oat 75.0 17.5 23.3 2.2 2.9 <0.1 1.3 47.5
Yellow foxtail 25.0 20.0 80.0 4.6 18.3 <0.1 4.0 39.0
Russian thistle 50.0 15.0 30.0 2.4 4.8 <0.1 2.0 37.3
Kochia 50.0 12.5 25.0 1.3 2.7 <0.1 1.0 32.3
Field pennycress 25.0 10.0 40.0 1.6 6.5 <0.1 3.0 22.1
Canola 25.0 7.5 30.0 0.8 3.2 <0.1 1.0 17.7
Field bindweed 25.0 5.0 20.0 0.5 2.2 <0.1 1.0 14.6
Weed free 33.6 11.8 35.2 - - - - -


Table 85. Bottineau county weed infestations based on 20 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Green foxtail 55.0 31.0 56.4 10.5 19.1 0.2 3.8 73.8
Yellow foxtail 55.0 19.0 34.5 12.9 23.4 0.4 7.1 67.3
Canada thistle 60.0 12.5 20.8 3.4 5.7 <0.1 2.7 40.4
Wild oat 60.0 14.0 23.3 2.5 4.2 <0.1 2.4 39.9
Wild buckwheat 50.0 14.0 28.0 2.4 4.8 <0.1 2.3 36.3
Kochia 50.0 8.0 16.0 1.2 2.4 <0.1 1.6 27.4
Common ragweed 25.0 3.5 14.0 6.5 25.8 0.3 16.8 26.9
Pigweed species 30.0 7.0 23.3 1.1 3.8 <0.1 1.7 19.6
Prickly lettuce 25.0 6.0 24.0 1.0 4.1 <0.1 1.8 16.7
Flixweed/Tansy mustard 10.0 5.0 50.0 1.0 9.7 <0.1 3.5 10.6
Perennial sowthistle 20.0 2.0 10.0 0.3 1.3 <0.1 1.3 9.3
Sunflower 15.0 3.0 20.0 0.4 2.5 <0.1 1.3 8.9
Common purslane 10.0 2.5 25.0 0.7 7.0 <0.1 4.0 7.5
Quackgrass 5.0 1.5 30.0 1.0 19.4 <0.1 10.0 5.4
Biennial wormwood 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Eastern black nightshade 5.0 1.5 30.0 0.2 4.3 <0.1 2.0 3.7
Common mallow 5.0 1.5 30.0 0.2 4.3 <0.1 2.0 3.7
Weed free 45.0 9.0 20.0 - - - - -


Table 86. Bowman county weed infestations based on 6 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Green foxtail 66.7 18.3 27.5 10.9 16.4 0.3 4.0 66.1
Wild buckwheat 50.0 11.7 23.3 1.4 2.9 <0.1 1.3 31.7
Russian thistle 50.0 8.3 16.7 0.9 1.8 <0.1 1.0 27.1
Volunteer cereal 16.7 11.7 70.0 2.9 17.2 <0.1 4.0 23.9
Kochia 33.3 8.3 25.0 0.9 2.7 <0.1 1.0 21.5
Field bindweed 33.3 5.0 15.0 0.5 1.6 <0.1 1.0 17.4
Safflower 16.7 6.7 40.0 0.9 5.4 <0.1 2.0 14.3
Wild oat 16.7 5.0 30.0 0.7 4.3 <0.1 2.0 12.2
Field pennycress 16.7 3.3 20.0 0.5 3.2 <0.1 2.0 10.1
Sunflower 16.7 1.7 10.0 0.2 1.1 <0.1 1.0 7.6
Prickly lettuce 16.7 1.7 10.0 0.2 1.1 <0.1 1.0 7.6
Pigweed species 16.7 1.7 10.0 0.2 1.1 <0.1 1.0 7.6
Weed free 50.0 18.3 36.7 - - - - -


Table 87. Burleigh county weed infestations based on 8 surveyed fields, summer 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Green foxtail 100.0 32.5 32.5 43.9 43.9 4.4 25.5 168.2
Wild oat 62.5 17.5 28.0 3.6 5.8 <0.1 2.6 46.8
Wild buckwheat 50.0 10.0 20.0 1.9 3.8 <0.1 1.8 31.1
Russian thistle 50.0 6.3 12.5 0.7 1.3 <0.1 1.0 24.5
Canada thistle 25.0 7.5 30.0 2.6 10.2 <0.1 5.5 21.8
Yellow foxtail 25.0 2.5 10.0 0.4 1.6 <0.1 1.5 11.8
Pigweed species 25.0