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 114. Ransom county weed infestations based on 11 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 90.9 40.9 45.0 9.8 10.8 0.1 3.0 94.0
Wild oat 36.4 11.8 32.5 3.2 8.9 <0.1 3.5 31.5
Kochia 45.5 12.7 28.0 1.4 3.0 <0.1 1.0 31.1
Canada thistle 36.4 9.1 25.0 1.3 3.5 <0.1 1.3 24.2
Quackgrass 27.3 5.5 20.0 0.6 2.2 <0.1 1.0 15.9
Common milkweed 27.3 4.5 16.7 0.5 1.8 <0.1 1.0 14.8
Biennial wormwood 18.2 3.6 20.0 0.4 2.2 <0.1 1.0 10.6
Green foxtail 9.1 4.5 50.0 0.7 7.5 <0.1 2.0 9.2
Hedge bindweed 9.1 3.6 40.0 0.6 6.5 <0.1 2.0 8.0
Common lambsquarters 9.1 2.7 30.0 0.4 4.3 <0.1 2.0 6.7
Eastern black nightshade 9.1 2.7 30.0 0.3 3.2 <0.1 1.0 6.4
Wild mustard 9.1 1.8 20.0 0.3 3.2 <0.1 2.0 5.5
Volunteer cereal 9.1 1.8 20.0 0.3 3.2 <0.1 2.0 5.5
Perennial sowthistle 9.1 1.8 20.0 0.2 2.2 <0.1 1.0 5.3
Common cocklebur 9.1 0.9 10.0 0.1 1.1 <0.1 1.0 4.2
Pigweed species 9.1 0.9 10.0 0.1 1.1 <0.1 1.0 4.2
Common ragweed 9.1 0.9 10.0 0.1 1.1 <0.1 1.0 4.2
Weed free 63.6 20.9 32.9 - - - - -

Table 115. Renville county weed infestations based on 5 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 50.0 62.5 24.5 30.7 0.2 6.3 133.9
Wild oat 40.0 6.0 15.0 15.7 39.3 0.6 8.0 56.0
Canada thistle 20.0 4.0 20.0 0.6 3.2 <0.1 2.0 12.2
Wild mustard 20.0 4.0 20.0 0.6 3.2 <0.1 2.0 12.2
Sunflower 20.0 4.0 20.0 0.4 2.2 <0.1 1.0 11.7
Smooth brome 20.0 2.0 10.0 1.1 5.4 <0.1 5.0 11.2
Quackgrass 20.0 2.0 10.0 0.9 4.3 <0.1 4.0 10.7
Kochia 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
Weed free 60.0 10.0 16.7 - - - - -

 

Table 116. Richland county weed infestations based on 32 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 46.9 14.4 30.7 7.5 16.0 0.2 5.6 47.5
Common lambsquarters 43.8 9.4 21.4 1.6 3.8 <0.1 2.0 27.8
Pigweed species 31.3 9.4 30.0 1.8 5.8 <0.1 2.4 24.0
Common ragweed 34.4 8.1 23.6 1.3 3.8 <0.1 1.9 22.6
Green foxtail 28.1 6.3 22.2 1.0 3.5 <0.1 1.8 17.9
Common cocklebur 31.3 4.7 15.0 0.5 1.7 <0.1 1.1 16.4
Common milkweed 28.1 4.1 14.4 0.7 2.5 <0.1 1.8 15.1
Wild-proso millet 25.0 3.8 15.0 0.7 2.7 <0.1 1.8 13.7
Kochia 15.6 4.4 28.0 1.2 7.5 <0.1 3.6 12.3
Barnyardgrass 15.6 3.1 20.0 0.4 2.4 <0.1 1.2 9.2
Wild oat 15.6 2.5 16.0 0.4 2.8 <0.1 2.0 8.7
Eastern black nightshade 12.5 2.8 22.5 0.4 3.0 <0.1 1.3 7.8
Soybean 15.6 1.9 12.0 0.3 1.7 <0.1 1.4 7.7
Field sandbur 6.3 2.8 45.0 0.9 14.5 <0.1 5.0 7.0
Canada thistle 12.5 1.6 12.5 0.3 2.4 <0.1 1.8 6.4
Wild buckwheat 12.5 1.3 10.0 0.2 1.9 <0.1 1.8 6.0
Sunflower 9.4 1.9 20.0 0.2 2.5 <0.1 1.3 5.5
Biennial wormwood 6.3 1.6 25.0 0.6 9.7 <0.1 6.5 5.1
Sweetclover 9.4 0.9 10.0 0.1 1.1 <0.1 1.0 4.3
Horseweed 6.3 1.3 20.0 0.2 3.2 <0.1 2.0 3.8
Marshelder 6.3 0.9 15.0 0.2 2.7 <0.1 2.0 3.4
Venice mallow 6.3 0.9 15.0 0.1 2.2 <0.1 1.5 3.3
Quackgrass 6.3 0.6 10.0 0.2 3.2 <0.1 3.0 3.2
Wild mustard 6.3 0.6 10.0 0.1 1.1 <0.1 1.0 2.9
Yellow nutsedge 3.1 0.6 20.0 0.1 4.3 <0.1 3.0 2.0
Prostrate pigweed 3.1 0.6 20.0 0.1 2.2 <0.1 1.0 1.8
Common purslane 3.1 0.3 10.0 0.1 3.2 <0.1 3.0 1.6
Annual smartweed 3.1 0.3 10.0 0.1 2.2 <0.1 2.0 1.5
Stinkgrass 3.1 0.3 10.0 <0.1 1.1 <0.1 1.0 1.4
Russian thistle 3.1 0.3 10.0 <0.1 1.1 <0.1 1.0 1.4
Hairy nightshade 3.1 0.3 10.0 <0.1 1.1 <0.1 1.0 1.4
Corn 3.1 0.3 10.0 <0.1 1.1 <0.1 1.0 1.4
Weed free 81.3 35.3 43.5 - - - - -

Table 117. Rolette 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 - -  
Wild buckwheat 87.5 35.0 40.0 25.7 29.4 0.5 6.4 124.1
Green foxtail 75.0 35.0 46.7 24.0 31.9 1.1 19.5 115.9
Pigweed species 87.5 25.0 28.6 17.1 19.5 0.1 7.0 94.0
Prickly lettuce 50.0 31.3 62.5 10.4 20.7 <0.1 7.5 72.1
Wild oat 50.0 11.3 22.5 10.0 19.9 0.3 5.3 51.1
Kochia 62.5 15.0 24.0 2.7 4.3 <0.1 2.2 42.1
Canada thistle 50.0 13.8 27.5 4.3 8.6 <0.1 4.8 40.5
Horseweed 50.0 13.8 27.5 2.8 5.7 <0.1 2.3 37.0
Shepherd's-purse 37.5 7.5 20.0 6.7 17.9 0.3 4.3 35.7
Field pennycress 37.5 8.8 23.3 4.4 11.8 <0.1 6.0 31.6
Canola 12.5 <0.1 <0.1 10.9 87.2 0.3 16.0 29.6
Flixweed/Tansy mustard 37.5 7.5 20.0 1.2 3.2 <0.1 2.0 22.8
Quackgrass 25.0 6.3 25.0 2.4 9.7 <0.1 5.0 20.2
Common mallow 37.5 5.0 13.3 0.8 2.2 <0.1 1.7 19.4
Common ragweed 37.5 3.8 10.0 0.5 1.4 <0.1 1.3 17.5
Yellow foxtail 12.5 5.0 40.0 2.0 16.1 <0.1 5.0 13.9
Nightflowering catchfly 12.5 3.8 30.0 0.9 7.5 <0.1 4.0 10.1
Volunteer cereal 12.5 1.3 10.0 1.1 8.6 <0.1 8.0 7.9
Field bindweed 12.5 2.5 20.0 0.3 2.2 <0.1 1.0 7.3
Wild mustard 12.5 1.3 10.0 0.3 2.2 <0.1 2.0 6.0
Tall waterhemp 12.5 1.3 10.0 0.1 1.1 <0.1 1.0 5.7
Sunflower 12.5 1.3 10.0 0.1 1.1 <0.1 1.0 5.7
Russian thistle 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 118. Sargent county weed infestations based on 15 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 24.0 36.0 4.1 6.1 <0.1 2.5 55.8
Yellow foxtail 53.3 25.3 47.5 4.6 8.6 <0.1 2.4 53.8
Kochia 33.3 8.0 24.0 0.9 2.8 <0.1 1.2 21.3
Wild oat 20.0 5.3 26.7 1.0 5.0 <0.1 2.3 14.3
Barnyardgrass 20.0 3.3 16.7 0.4 2.2 <0.1 1.3 11.0
Wild-proso millet 13.3 4.7 35.0 0.6 4.8 <0.1 2.0 10.6
Common ragweed 20.0 2.7 13.3 0.3 1.4 <0.1 1.0 10.0
Soybean 20.0 2.7 13.3 0.3 1.4 <0.1 1.0 10.0
Eastern black nightshade 20.0 2.7 13.3 0.3 1.4 <0.1 1.0 10.0
Canada thistle 20.0 2.7 13.3 0.3 1.4 <0.1 1.0 10.0
Quackgrass 13.3 3.3 25.0 0.4 3.2 <0.1 1.5 8.8
Common lambsquarters 13.3 2.7 20.0 0.4 2.7 <0.1 1.5 7.9
Biennial wormwood 13.3 2.7 20.0 0.3 2.2 <0.1 1.0 7.8
Common milkweed 13.3 2.0 15.0 0.3 2.2 <0.1 1.5 7.1
Sweetclover 6.7 1.3 20.0 0.1 2.2 <0.1 1.0 3.9
Sunflower 6.7 1.3 20.0 0.1 2.2 <0.1 1.0 3.9
Prairie wild rose 6.7 1.3 20.0 0.1 2.2 <0.1 1.0 3.9
Annual smartweed 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Yellow woodsorrel 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Wild buckwheat 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Curly dock 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Corn 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Weed free 80.0 26.0 32.5 - - - - -

 

Table 119. Sheridan county weed infestations based on 10 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 31.0 31.0 21.2 21.2 0.3 7.1 113.8
Kochia 80.0 15.0 18.8 5.6 7.0 0.1 2.4 54.7
Wild oat 50.0 24.0 48.0 3.8 7.5 <0.1 2.0 49.5
Yellow foxtail 40.0 12.0 30.0 2.6 6.5 1.0 10.5 31.4
Marshelder 40.0 8.0 20.0 1.0 2.4 <0.1 1.3 23.6
Wild buckwheat 30.0 8.0 26.7 1.2 3.9 <0.1 2.0 20.8
Russian thistle 40.0 4.0 10.0 0.4 1.1 <0.1 1.0 18.3
Field bindweed 30.0 5.0 16.7 0.6 2.2 <0.1 1.3 16.5
Canada thistle 30.0 4.0 13.3 0.4 1.4 <0.1 1.0 15.0
Eastern black nightshade 30.0 3.0 10.0 0.3 1.1 <0.1 1.0 13.8
Common ragweed 20.0 3.0 15.0 0.3 1.6 <0.1 1.0 10.4
Volunteer cereal 20.0 3.0 15.0 0.3 1.6 <0.1 1.0 10.4
Wild mustard 10.0 3.0 30.0 0.3 3.2 <0.1 1.0 7.1
Prairie wild rose 10.0 2.0 20.0 0.2 2.2 <0.1 1.0 5.8
Common cocklebur 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Common lambsquarters 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Perennial sowthistle 10.0 1.0 10.0 0.1 1.1 <0.1 1.0 4.6
Weed free 40.0 13.0 32.5 - - - - -

Table 120. Sioux county weed infestations based on 5 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 - -