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 98. Griggs county weed infestations based on 12 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 80.0 33.0 41.3 11.7 14.7 <0.1 4.1 87.0
Yellow foxtail 60.0 24.0 40.0 11.8 19.7 0.1 7.5 71.6
Volunteer cereal 50.0 15.0 30.0 1.8 3.7 <0.1 1.4 35.9
Wild oat 30.0 11.0 36.7 4.7 15.8 <0.1 5.0 32.1
Kochia 40.0 13.0 32.5 1.9 4.8 <0.1 2.3 30.9
Biennial wormwood 40.0 7.0 17.5 1.8 4.6 <0.1 3.5 24.6
Quackgrass 30.0 5.0 16.7 1.3 4.3 <0.1 3.3 18.0
Marshelder 10.0 7.0 70.0 0.8 7.5 <0.1 1.0 12.1
Pigweed species 20.0 4.0 20.0 0.4 2.2 <0.1 1.0 11.7
Soybean 10.0 6.0 60.0 1.0 9.7 <0.1 2.0 11.6
Eastern black nightshade 20.0 2.0 10.0 0.2 1.1 <0.1 1.0 9.2
Wild buckwheat 20.0 2.0 10.0 0.2 1.1 <0.1 1.0 9.2
Common lambsquarters 10.0 3.0 30.0 0.3 3.2 <0.1 1.0 7.1
Perennial sowthistle 10.0 2.0 20.0 0.3 3.2 <0.1 2.0 6.1
Canada thistle 10.0 1.0 10.0 0.2 2.2 <0.1 2.0 4.8
Common cocklebur 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Yellow woodsorrel 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Sweetclover 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Common mallow 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Erect knotweed 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Prostrate pigweed 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Weed free 70.0 23.0 32.9 - - - - -



Table 99. Hettinger county weed infestations based on 14 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 78.6 36.4 46.4 7.5 9.6 <0.1 3.5 80.2
Wild oat 78.6 24.3 30.9 5.5 6.9 <0.1 2.8 63.2
Kochia 64.3 20.7 32.2 2.9 4.5 <0.1 1.8 49.0
Wild buckwheat 64.3 19.3 30.0 2.7 4.2 <0.1 1.6 47.0
Sunflower 35.7 10.7 30.0 1.4 3.9 <0.1 1.6 25.8
Curly dock 35.7 6.4 18.0 0.8 2.4 <0.1 1.4 20.3
Field bindweed 28.6 5.0 17.5 0.7 2.4 <0.1 1.5 16.1
Russian thistle 21.4 5.7 26.7 0.8 3.6 <0.1 1.7 14.7
Common lambsquarters 21.4 5.0 23.3 0.7 3.2 <0.1 1.7 13.8
Pigweed species 14.3 2.9 20.0 0.4 2.7 <0.1 1.5 8.5
Volunteer cereal 7.1 2.9 40.0 0.6 8.6 <0.1 4.0 6.7
Flixweed/Tansy mustard 7.1 2.1 30.0 0.2 3.2 <0.1 1.0 5.1
Prickly lettuce 7.1 1.4 20.0 0.2 2.2 <0.1 1.0 4.2
Prairie wild rose 7.1 0.7 10.0 0.1 1.1 <0.1 1.0 3.3
Field pennycress 7.1 0.7 10.0 0.1 1.1 <0.1 1.0 3.3
Weed free 7.1 0.7 10.0 - - - - -



Table 100. Kidder 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 100.0 45.0 45.0 19.7 19.7 1.5 11.8 124.4
Wild buckwheat 66.7 36.7 55.0 19.0 28.5 0.2 11.5 103.3
Field bindweed 66.7 18.3 27.5 3.0 4.6 <0.1 2.5 47.7
Canada thistle 83.3 13.3 16.0 2.0 2.4 <0.1 1.6 45.7
Quackgrass 16.7 10.0 60.0 10.0 60.3 <0.1 17.0 39.0
Wild mustard 16.7 13.3 80.0 6.1 36.6 <0.1 10.0 33.1
Prairie wild rose 50.0 10.0 20.0 1.3 2.5 <0.1 1.3 29.6
Wild oat 33.3 8.3 25.0 2.2 6.5 <0.1 4.5 24.5
Yellow foxtail 33.3 5.0 15.0 1.3 3.8 <0.1 3.0 19.0
Common lambsquarters 33.3 5.0 15.0 0.7 2.2 <0.1 1.5 17.8
Perennial sowthistle 16.7 5.0 30.0 1.4 8.6 <0.1 5.0 13.9
Common cocklebur 16.7 3.3 20.0 0.4 2.2 <0.1 1.0 9.7
Leafy spurge 16.7 1.7 10.0 0.7 4.3 <0.1 4.0 8.9
Prostrate pigweed 16.7 1.7 10.0 0.2 1.1 <0.1 1.0 7.6
Dandelion 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 0.0 1.0 7.6



Table 101. LaMoure 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 - -  
Yellow foxtail 65.0 21.5 33.1 16.0 24.7 0.3 7.9 80.6
Canada thistle 60.0 24.0 40.0 8.6 14.4 <0.1 4.3 64.1
Green foxtail 55.0 14.0 25.5 11.6 21.1 0.8 8.1 59.5
Wild oat 30.0 14.5 48.3 7.8 25.8 <0.1 7.3 42.6
Wild buckwheat 35.0 11.5 32.9 4.1 11.8 <0.1 3.4 32.8
Eastern black nightshade 30.0 13.0 43.3 2.7 9.0 <0.1 3.0 29.3
Kochia 20.0 10.0 50.0 5.2 26.1 <0.1 6.8 28.8
Pigweed species 30.0 11.0 36.7 3.1 10.2 <0.1 3.7 28.2
Volunteer cereal 15.0 5.0 33.3 3.3 22.2 <0.1 6.0 17.8
Quackgrass 20.0 4.5 22.5 1.3 6.5 <0.1 2.8 14.2
Horseweed 10.0 1.5 15.0 3.9 38.8 0.1 9.5 13.9
Common lambsquarters 10.0 4.0 40.0 1.0 10.2 <0.1 3.0 9.7
Field bindweed 5.0 3.5 70.0 1.8 36.6 <0.1 8.0 9.4
Common ragweed 10.0 2.0 20.0 0.4 3.8 <0.1 2.0 6.2
Sunflower 5.0 2.0 40.0 0.4 8.6 <0.1 4.0 4.7
Perennial sowthistle 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Common milkweed 5.0 1.5 30.0 0.6 11.8 <0.1 5.0 4.5
Hairy nightshade 5.0 2.0 40.0 0.3 5.4 <0.1 2.0 4.3
Common cocklebur 5.0 1.5 30.0 0.2 4.3 <0.1 2.0 3.7
Field pennycress 5.0 1.0 20.0 0.2 3.2 <0.1 2.0 3.0
Flax 5.0 0.5 10.0 0.1 2.2 <0.1 2.0 2.4
Curly dock 5.0 0.5 10.0 0.1 1.1 <0.1 1.0 2.3
Prairie wild rose 5.0 0.5 10.0 0.1 1.1 <0.1 1.0 2.3
Wild mustard 5.0 0.5 10.0 0.1 1.1 <0.1 1.0 2.3
Weed free 55.0 20.0 36.4 - - - - -



Table 102. Logan 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 83.3 31.7 38.0 29.8 35.7 0.2 12.2 128.9
Wild buckwheat 66.7 15.0 22.5 2.2 3.2 <0.1 1.5 42.2
Russian thistle 66.7 8.3 12.5 0.9 1.3 <0.1 1.0 32.6
Prostrate pigweed 16.7 11.7 70.0 2.7 16.1 <0.1 50.0 23.5
Wild oat 16.7 5.0 30.0 1.1 6.5 <0.1 3.0 13.1
Yellow woodsorrel 16.7 3.3 20.0 0.5 3.2 <0.1 2.0 10.1
Hedge bindweed 16.7 3.3 20.0 0.4 2.2 <0.1 1.0 9.7
Hairy nightshade 16.7 1.7 10.0 0.5 3.2 <0.1 3.0 8.5
Kochia 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
Yellow foxtail 16.7 1.7 10.0 0.2 1.1 <0.1 1.0 7.6
Weed free 66.7 25.0 37.5 - - - - -



Table 103. McHenry county weed infestations based on 13 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 30.0 30.0 42.6 42.6 5.2 27.5 162.8
Wild buckwheat 53.8 18.5 34.3 4.5 8.3 <0.1 3.6 46.8
Wild oat 38.5 13.1 34.0 5.4 14.0 <0.1 5.0 38.5
Quackgrass 23.1 4.6 20.0 3.7 16.1 <0.1 9.7 21.0
Field bindweed 23.1 6.9 30.0 2.3 10.0 <0.1 4.7 20.0
Kochia 23.1 6.9 30.0 2.1 9.0 <0.1 3.7 19.4
Canada thistle 15.4 4.6 30.0 1.8 11.8 <0.1 6.0 14.0
Giant ragweed 23.1 4.6 20.0 0.6 2.5 <0.1 1.3 13.7
Common ragweed 15.4 4.6 30.0 0.8 5.4 <0.1 2.5 11.7
Pigweed species 7.7 3.1 40.0 0.7 8.6 <0.1 3.0 7.2
Leafy spurge 7.7 2.3 30.0 0.9 11.8 <0.1 5.0 7.0
Sunflower 7.7 1.5 20.0 0.2 3.2 <0.1 2.0 4.7
Common milkweed 7.7 0.8 10.0 0.2 3.2 <0.1 3.0 3.9
Russian thistle 7.7 0.8 10.0 0.1 1.1 <0.1 1.0 3.5
Weed free 30.8 7.7 25.0 - - - - -



Table 104. McIntosh 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 - -  
Yellow foxtail 75.0 36.3 48.3 16.6 22.1 0.9 13.8 99.9
Wild buckwheat 62.5 22.5 36.0 20.2 32.3 0.8 10.6 90.4
Wild oat 62.5 23.8 38.0 7.9 12.7 <0.1 5.4 63.1
Kochia 50.0 21.3 42.5 5.1 10.2 <0.1 3.8 49.8
Field bindweed 37.5 12.5 33.3 5.7 15.1 <0.1 4.3 38.2
Canada thistle 12.5 7.5 60.0 4.8 38.8 <0.1 12.0 23.0
Field pennycress 12.5 8.8 70.0 2.3 18.3 <0.1 5.0 18.3
Wild mustard 25.0 5.0 20.0 2.0 8.1 <0.1 4.5 18.0
Volunteer cereal 12.5 5.0 40.0 1.3 10.8 <0.1 4.0 12.3
Pigweed species 12.5 5.0 40.0 0.9 7.5 <0.1 3.0 11.4
Green foxtail 12.5 2.5 20.0 0.4 3.2 <0.1 2.0 7.6
Giant foxtail 12.5 2.5 20.0 0.4 3.2 <0.1 2.0 7.6
Prickly lettuce