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 50. Ransom county weed infestations based on 15 surveyed fields, spring 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 100.0 30.0 30.0 26.1 26.1 2.6 19.5 124.3
Common lambsquarters 53.3 22.0 41.3 19.1 35.8 0.1 20.5 84.3
Barnyardgrass 40.0 17.3 43.3 9.3 23.3 <0.1 16.5 52.4
Canada thistle 60.0 14.7 24.4 3.7 6.2 <0.1 2.8 43.4
Wild oat 26.7 6.7 25.0 11.6 43.6 0.3 19.0 42.7
Wild-proso millet 20.0 12.0 60.0 10.0 49.9 <0.1 26.7 41.9
Pigweed species 40.0 14.0 35.0 5.1 12.7 <0.1 16.8 39.2
Wild mustard 40.0 10.7 26.7 2.4 6.1 <0.1 3.3 29.7
Sunflower 26.7 8.7 32.5 1.3 4.8 <0.1 2.0 20.6
Wild buckwheat 26.7 8.0 30.0 1.4 5.1 <0.1 2.5 20.1
Kochia 26.7 5.3 20.0 2.1 7.8 <0.1 6.3 19.1
Eastern black nightshade 13.3 4.7 35.0 3.5 26.4 <0.1 17.0 17.3
Common milkweed 26.7 4.0 15.0 0.6 2.4 <0.1 1.8 14.4
Canola 13.3 1.3 10.0 1.9 14.5 0.1 26.0 10.3
Quackgrass 13.3 2.7 20.0 1.0 7.5 <0.1 6.0 9.5
Field bindweed 13.3 3.3 25.0 0.4 3.2 <0.1 1.5 8.8
Common ragweed 13.3 2.7 20.0 0.6 4.8 <0.1 3.5 8.6
Green foxtail 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
Perennial sowthistle 13.3 2.0 15.0 0.4 2.7 <0.1 1.5 7.3
Yellow woodsorrel 13.3 1.3 10.0 0.1 1.1 <0.1 1.0 6.1
Volunteer cereal 6.7 2.0 30.0 0.4 5.4 <0.1 3.0 5.1
Hedge bindweed 6.7 1.3 20.0 0.1 2.2 <0.1 1.0 3.9
Common cocklebur 6.7 0.7 10.0 0.3 4.3 <0.1 4.0 3.6
Flax 6.7 0.7 10.0 0.1 2.2 <0.1 2.0 3.2
Dandelion 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Common mallow 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Nightflowering catchfly 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Prostrate spurge 6.7 0.7 10.0 0.1 1.1 <0.1 1.0 3.1
Weed free 13.3 2.7 20.0 - - - - -

Table 51. Renville county weed infestations based on 34 surveyed fields, spring 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 82.4 24.7 30.0 32.9 39.9 4.5 45.3 128.8
Wild buckwheat 67.6 29.7 43.9 7.6 11.3 <0.1 4.1 70.1
Pigweed species 41.2 16.8 40.7 7.7 18.8 <0.1 15.1 48.5
Canada thistle 64.7 15.0 23.2 4.6 7.1 <0.1 4.1 47.4
Wild oat 44.1 7.9 18.0 4.3 9.7 0.1 4.2 32.6
Kochia 44.1 11.2 25.3 2.5 5.6 <0.1 3.2 31.6
Field pennycress 32.4 10.6 32.7 3.7 11.4 <0.1 5.8 30.0
Volunteer cereal 38.2 10.3 26.9 2.7 7.0 <0.1 3.4 29.3
Common ragweed 32.4 7.4 22.7 4.1 12.5 <0.1 8.5 27.6
Wild mustard 35.3 6.8 19.2 2.3 6.5 0.1 5.3 23.8
Yellow foxtail 14.7 5.6 38.0 5.6 38.3 0.1 13.0 23.6
Sunflower 26.5 6.8 25.6 1.4 5.3 <0.1 2.1 18.8
Quackgrass 17.6 4.4 25.0 1.6 8.8 <0.1 5.5 13.9
Canola 17.6 4.7 26.7 0.7 4.1 <0.1 1.5 12.3
Annual smartweed 14.7 3.5 24.0 1.3 8.6 <0.1 5.2 11.4
Common lambsquarters 14.7 3.5 24.0 0.9 6.2 <0.1 2.4 10.6
Perennial sowthistle 14.7 2.6 18.0 1.0 7.1 <0.1 5.0 10.0
Biennial wormwood 11.8 4.4 37.5 0.6 5.4 <0.1 2.3 9.8
Field bindweed 14.7 2.9 20.0 0.4 3.0 <0.1 1.6 8.9
Russian thistle 5.9 2.4 40.0 0.9 14.5 <0.1 4.5 6.3
Common mallow 8.8 1.5 16.7 0.6 6.8 <0.1 5.7 5.8
Prickly lettuce 5.9 2.1 35.0 0.4 7.5 <0.1 3.0 5.1
Curly dock 5.9 1.2 20.0 0.7 11.8 <0.1 9.5 4.8
Flax 5.9 0.6 10.0 0.1 2.2 <0.1 2.0 2.8
Flixweed/Tansy mustard 2.9 0.6 20.0 0.1 2.2 <0.1 1.0 1.7
Nightflowering catchfly 2.9 0.6 20.0 0.1 2.2 <0.1 1.0 1.7
Lentil 2.9 <0.1 <0.1 0.3 9.7 0.1 44.0 1.6
Sweetclover 2.9 0.3 10.0 0.1 2.2 <0.1 2.0 1.4
Common purslane 2.9 0.3 10.0 <0.1 1.1 <0.1 1.0 1.3
False chamomile 2.9 0.3 10.0 <0.1 1.1 <0.1 1.0 1.3
Common cocklebur 2.9 0.3 10.0 <0.1 1.1 <0.1 1.0 1.3
Lanceleaf sage 2.9 0.3 10.0 <0.1 1.1 <0.1 1.0 1.3
Weed free 23.5 6.5 27.5 - - - - -

Table 52. Richland county weed infestations based on 61 surveyed fields, spring 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed
Weed species Frequency All Infested All Infested Low High Index
  (%) (%) (%) - - Plants/m2 - - - - Plants/m2 - -  
Common lambsquarters 65.6 23.0 35.0 16.9 25.8 0.2 9.5 84.3
Green foxtail 47.5 17.2 36.2 11.6 24.3 0.5 14.8 60.0
Yellow foxtail 34.4 11.8 34.3 10.0 29.2 0.2 14.0 46.7
Common cocklebur 45.9 16.7 36.4 4.2 9.1 <0.1 4.7 41.8
Soybean 39.3 16.1 40.8 2.9 7.4 <0.1 2.7 35.9
Eastern black nightshade 39.3 12.0 30.4 3.9 9.9 <0.1 3.3 34.1
Wild-proso millet 27.9 10.3 37.1 5.6 20.1 <0.1 8.5 32.7
Wild buckwheat 32.8 9.8 30.0 2.2 6.8 <0.1 2.4 26.0
Common ragweed 24.6 9.2 37.3 2.6 10.4 <0.1 4.1 23.3
Canada thistle 36.1 6.7 18.6 1.1 3.2 <0.1 1.9 21.4
Wild mustard 32.8 6.4 19.5 1.2 3.6 <0.1 2.3 20.1
Pigweed species 18.0 5.4 30.0 1.5 8.3 <0.1 4.6 14.9
Volunteer cereal 13.1 4.6 35.0 2.2 16.6 <0.1 4.5 14.0
Kochia 13.1 4.1 31.3 1.3 9.6 <0.1 5.3 11.4
Field sandbur 3.3 <0.1 <0.1 3.0 91.5 0.1 33.5 8.1
Quackgrass 9.8 3.0 30.0 0.6 6.5 <0.1 2.2 7.7
Perennial sowthistle 11.5 2.3 20.0 0.4 3.8 <0.1 2.3 7.1
Sunflower 8.2 2.8 34.0 0.6 7.3 <0.1 2.6 6.9
Common milkweed 13.1 1.8 13.8 0.2 1.9 <0.1 1.3 6.8
Lanceleaf sage 4.9 2.6 53.3 0.9 18.3 <0.1 5.7 6.4
Russian thistle 6.6 1.8 27.5 0.5 7.3 <0.1 2.8 5.1
Wild oat 4.9 0.8 16.7 0.6 11.5 <0.1 3.3 3.8
Horseweed 4.9 1.6 33.3 0.2 3.9 <0.1 1.3 3.7
Field bindweed 6.6 0.8 12.5 0.1 1.6 <0.1 1.3 3.3
Sweetclover 3.3 1.3 40.0 0.2 5.9 <0.1 2.5 2.9
Corn 4.9 0.7 13.3 0.1 1.8 <0.1 1.3 2.5
Swamp smartweed 3.3 1.0 30.0 0.1 3.2 <0.1 1.0 2.3
Biennial wormwood 3.3 0.7 20.0 0.1 2.2 <0.1 1.0 1.9
Yellow nutsedge 3.3 0.3 10.0 0.1 3.8 <0.1 3.5 1.7
Tall waterhemp 3.3 0.5 15.0 0.1 1.6 <0.1 1.0 1.7
Dandelion 3.3 0.3 10.0 0.1 1.6 <0.1 1.5 1.5
Hairy nightshade 3.3 0.3 10.0 <0.1 1.1 <0.1 1.0 1.5
Barnyardgrass 1.6 0.7 40.0 0.1 6.5 <0.1 3.0 1.4
Prostrate pigweed 1.6 0.5 30.0 0.1 3.2 <0.1 1.0 1.2
Yellow woodsorrel 1.6 0.3 20.0 <0.1 2.2 <0.1 1.0 1.0
Common purslane 1.6 0.3 20.0 <0.1 2.2 <0.1 1.0 1.0
Purslane speedwell 1.6 0.2 10.0 <0.1 1.1 <0.1 1.0 0.8
Prairie wild rose 1.6 0.2 10.0 <0.1 1.1 <0.1 1.0 0.8
Weed free 41.0 11.3 27.6 - - - - -

Table 53. Rolette county weed infestations based on 14 surveyed fields, spring 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 42.9 42.9 32.6 32.6 2.6 22.9 152.3
Wild oat 85.7 41.4 48.3 30.1 35.1 0.5 9.5 140.1
Wild buckwheat 100.0 27.1 27.1 16.3 16.3 0.4 6.4 98.5
Wild mustard 85.7 33.6 39.2 12.1 14.1 <0.1 5.3 90.3
Annual smartweed 57.1 12.9 22.5 12.1 21.1 3.8 32.0 60.1
Pigweed species 57.1 17.9 31.3 8.1 14.1 0.1 3.8 55.7
Kochia 28.6 16.4 57.5 6.4 22.3 <0.1 10.3 40.8
Common lambsquarters 28.6 12.1 42.5 7.2 25.0 <0.1 11.3 38.4
Quackgrass 42.9 10.7 25.0 4.5 10.4 <0.1 4.7 35.4
Sunflower 21.4 10.7 50.0 4.1 19.0 <0.1 7.0 27.4
Field pennycress 42.9 7.1 16.7 2.5 5.7 <0.1 3.5 27.2
Canada thistle 35.7 7.1 20.0 1.4 3.9 <0.1 2.2 22.3
Volunteer cereal 35.7 7.1 20.0 1.2 3.4 <0.1 1.8 21.9
Canola 21.4 6.4 30.0 2.0 9.3 0.1 13.3 18.2
Nightflowering catchfly 14.3 6.4 45.0 2.7 18.8 <0.1 4.0 17.5
Common chickweed 28.6 3.6 12.5 1.2 4.3 0.3 8.5 16.0
Common mallow 14.3 6.4 45.0 1.5 10.8 <0.1 5.0 14.8
Common ragweed 21.4 2.1 10.0 0.9 4.3 <0.1 4.0 11.4
Prickly lettuce 14.3 2.1 15.0 0.4 2.7 <0.1 2.0 7.8
Dandelion 7.1 2.1 30.0 0.6 8.6 <0.1 4.0 6.0
Prostrate pigweed 7.1 0.7 10.0 0.3 4.3 <0.1 4.0 3.8
Giant ragweed 7.1 0.7 10.0 0.1 1.1 <0.1 1.0 3.3
Field bindweed 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 54. Sargent county weed infestations based on 29 surveyed fields, spring 2000.
        Weed  
  Weed Field Uniformity Weed Density Density Range Weed