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 76. North Dakota weed infestations in current crop of HRS wheat, durum and barley based on 374 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 57.1 21.4 37.4 18.0 31.5 0.9 12.8 82.3
Wild oat 53.5 19.9 37.1 6.4 12.0 0.1 4.1 52.6
Yellow foxtail 31.5 12.2 38.7 8.8 27.9 0.5 14.0 43.2
Wild buckwheat 38.0 12.6 33.0 4.3 11.3 <0.1 4.2 35.3
Kochia 41.3 13.4 32.4 3.5 8.4 <0.1 3.4 35.3
Canada thistle 31.5 9.1 28.8 2.6 8.2 <0.1 3.4 25.6
Pigweed species 22.6 6.5 28.8 2.0 8.9 <0.1 3.5 18.7
Field bindweed 12.0 3.3 27.5 1.1 9.3 <0.1 3.5 9.9
Quackgrass 12.2 2.7 22.0 1.0 7.9 <0.1 3.9 9.0
Common lambsquarters 11.4 2.7 24.0 0.6 5.0 <0.1 2.2 7.9
Common ragweed 9.0 2.7 30.6 0.8 8.9 <0.1 3.6 7.6
Russian thistle 9.2 2.3 25.0 0.6 6.6 <0.1 2.7 6.8
Common milkweed 11.1 2.0 18.0 0.4 3.9 <0.1 2.3 6.7
Perennial sowthistle 6.8 1.8 27.2 0.3 4.7 <0.1 1.9 4.8
Sunflower 6.8 1.3 19.6 0.2 3.4 <0.1 1.8 4.1
Wild mustard 5.7 1.3 22.4 0.4 6.2 <0.1 2.6 4.0
Field pennycress 4.3 1.4 31.9 0.4 9.7 <0.1 3.7 3.8
Barnyardgrass 4.9 1.2 23.9 0.2 3.6 <0.1 1.7 3.2
Common cocklebur 4.3 1.1 25.0 0.2 4.1 <0.1 1.9 3.0
Common mallow 4.1 0.7 17.3 0.2 5.4 <0.1 3.7 2.6
Prickly lettuce 4.1 0.9 22.0 0.1 3.7 <0.1 2.0 2.6
Eastern black nightshade 3.8 0.9 23.6 0.1 3.9 <0.1 1.8 2.5
Volunteer cereal 2.7 0.8 30.0 0.3 9.5 <0.1 3.0 2.3
Common purslane 2.2 0.7 33.8 0.2 7.3 <0.1 2.8 1.8
Hairy nightshade 2.2 0.6 26.3 0.2 8.2 <0.1 2.4 1.7
Soybean 3.0 0.5 17.3 0.1 2.6 <0.1 1.5 1.7
Prairie wild rose 3.0 0.4 12.7 <0.1 1.5 <0.1 1.1 1.5
Biennial wormwood 2.2 0.5 21.3 0.1 5.2 <0.1 3.1 1.5
Flixweed/Tansy mustard 1.9 0.6 30.0 0.1 5.1 <0.1 2.4 1.4
Horseweed 1.4 0.3 20.0 0.3 18.5 <0.1 5.2 1.3
Shepherd's-purse 1.4 0.3 24.0 0.2 14.2 <0.1 3.8 1.2
Wild-proso millet 1.9 0.3 17.1 0.1 3.1 <0.1 1.9 1.1
Canola 1.1 0.4 35.0 0.1 9.7 <0.1 2.0 1.0
Annual smartweed 1.4 0.3 24.0 0.1 5.8 <0.1 1.8 1.0
Yellow woodsorrel 1.4 0.3 24.0 0.1 3.9 <0.1 1.6 0.9
Buffalobur 0.5 0.3 50.0 0.2 34.4 <0.1 15.0 0.9
Hedge bindweed 1.1 0.3 30.0 0.1 5.7 <0.1 2.0 0.8
Prostrate pigweed 1.1 0.3 27.5 0.1 5.7 <0.1 13.8 0.8
Sweetclover 1.4 0.2 18.0 <0.1 2.6 <0.1 1.6 0.8
Dandelion 1.4 0.2 16.0 <0.1 2.6 <0.1 1.8 0.8
Field sandbur 0.5 0.3 55.0 0.1 21.0 <0.1 7.5 0.7
Marshelder 1.4 0.2 12.0 <0.1 1.9 <0.1 1.6 0.7
Curly dock 1.4 0.1 10.0 <0.1 1.3 <0.1 1.2 0.6
False chamomile 0.5 0.3 50.0 0.1 10.2 <0.1 3.0 0.6
Flax 0.8 0.2 23.3 <0.1 4.3 <0.1 2.3 0.5
Dry bean 0.8 0.2 20.0 <0.1 3.2 <0.1 2.0 0.5
Nightflowering catchfly 0.5 0.1 20.0 <0.1 3.8 <0.1 2.5 0.3
Downy brome 0.5 0.1 15.0 <0.1 3.2 <0.1 2.5 0.3
Giant foxtail 0.5 0.1 15.0 <0.1 2.2 <0.1 1.5 0.3
Venice mallow 0.5 0.1 15.0 <0.1 2.2 <0.1 1.5 0.3
Alfalfa 0.5 0.1 15.0 <0.1 1.6 <0.1 1.0 0.3
Lanceleaf sage 0.5 0.1 15.0 <0.1 1.6 <0.1 1.0 0.3
Smooth brome 0.5 0.1 10.0 <0.1 1.6 <0.1 1.5 0.3
Yellow nutsedge 0.3 0.1 30.0 <0.1 6.5 <0.1 3.0 0.2
Safflower 0.3 0.1 30.0 <0.1 3.2 <0.1 1.0 0.2
Leafy spurge 0.3 0.1 20.0 <0.1 5.4 <0.1 3.0 0.2
Erect knotweed 0.3 0.1 20.0 <0.1 2.2 <0.1 1.0 0.2
Foxtail barley 0.3 <0.1 10.0 <0.1 2.2 <0.1 2.0 0.1
Corn 0.3 <0.1 10.0 <0.1 1.1 <0.1 1.0 0.1
Tall waterhemp 0.3 <0.1 10.0 <0.1 1.1 <0.1 1.0 0.1
Western wheatgrass 0.3 <0.1 10.0 <0.1 1.1 <0.1 1.0 0.1
Witchgrass 0.3 <0.1 10.0 <0.1 1.1 <0.1 1.0 0.1
Weed free 47.6 14.4 30.3 - - - -  


Table 77. North Dakota weed infestations in current crop of canola based on 23 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 oat 52.6 29.5 56.0 6.3 11.9 <0.1 3.5 61.7
Kochia 52.6 22.6 43.0 4.8 9.0 <0.1 3.1 53.8
Canada thistle 42.1 18.4 43.8 3.7 8.9 <0.1 2.8 41.2
Wild mustard 36.8 18.4 50.0 2.5 6.8 <0.1 1.6 36.5
Giant ragweed 21.1 10.0 47.5 1.6 7.5 <0.1 1.8 20.7
Perennial sowthistle 26.3 8.9 34.0 1.1 4.3 <0.1 1.6 20.4
Green foxtail 10.5 4.7 45.0 3.0 28.5 <0.1 10.0 15.3
Volunteer cereal 15.8 5.8 36.7 1.3 8.3 <0.1 3.3 14.1
Flixweed/Tansy mustard 15.8 5.3 33.3 0.7 4.3 <0.1 1.3 12.1
Common lambsquarters 15.8 5.3 33.3 0.7 4.3 <0.1 1.3 12.1
Quackgrass 10.5 3.7 35.0 0.5 4.8 <0.1 1.5 8.4
Common ragweed 10.5 2.6 25.0 0.7 6.5 <0.1 2.0 7.7
Sunflower 10.5 1.6 15.0 0.2 2.2 <0.1 1.5 5.6
False chamomile 5.3 2.1 40.0 0.3 6.5 <0.1 2.0 4.7
Wild buckwheat 5.3 2.1 40.0 0.3 5.4 <0.1 2.0 4.5
Pigweed species 5.3 2.1 40.0 0.3 5.4 <0.1 2.0 4.5
Barnyardgrass 5.3 1.6 30.0 0.2 4.3 <0.1 2.0 3.9
Common mallow 5.3 1.6 30.0 0.2 4.3 <0.1 2.0 3.9
Dandelion 5.3 1.1 20.0 0.2 4.3 <0.1 3.0 3.3
Musk thistle 5.3 0.5 10.0 0.1 1.1 <0.1 1.0 2.4
Common cocklebur 5.3 0.5 10.0 0.1 1.1 <0.1 1.0 2.4
Field pennycress 5.3 0.5 10.0 0.1 1.1 <0.1 1.0 2.4
Weed free 84.2 20.5 24.4 - - - - -
 

Table 78. North Dakota weed infestations in current crop of soybean and dry bean based on 108 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 35.4 11.1 31.4 3.2 9.1 <0.1 3.1 30.4
Yellow foxtail 27.3 9.4 34.4 2.9 10.8 <0.1 3.7 25.3
Canada thistle 31.3 8.5 27.1 1.4 4.6 <0.1 2.0 22.3
Kochia 25.3 9.1 36.0 1.8 7.0 <0.1 2.4 21.6
Pigweed species 16.2 5.3 32.5 1.0 6.2 <0.1 2.3 13.0
Volunteer cereal 14.1 4.1 29.3 0.9 6.6 <0.1 2.1 11.0
Common ragweed 17.2 3.3 19.4 0.5 3.0 <0.1 1.8 10.3
Wild oat 11.1 3.7 33.6 0.6 5.6 <0.1 2.3 8.9
Common lambsquarters 13.1 3.1 23.8 0.5 3.6 <0.1 1.6 8.6
Wild buckwheat 13.1 2.8 21.5 0.5 4.1 <0.1 1.8 8.5
Common cocklebur 10.1 3.1 31.0 0.5 5.3 <0.1 2.0 7.7
Eastern black nightshade 9.1 3.1 34.4 0.5 5.7 <0.1 1.8 7.4
Biennial wormwood 11.1 2.2 20.0 0.4 3.6 <0.1 2.1 6.9
Quackgrass 10.1 2.1 21.0 0.5 5.4 <0.1 2.7 6.8
Wild mustard 9.1 2.3 25.6 0.3 3.0 <0.1 1.2 6.0
Sunflower 8.1 2.2 27.5 0.4 5.1 <0.1 2.1 5.9
Common milkweed 8.1 1.7 21.3 0.3 3.4 <0.1 1.6 5.0
Field pennycress 3.0 1.1 36.7 0.4 12.9 <0.1 7.3 3.0
Common mallow 5.1 0.8 16.0 0.1 2.8 <0.1 1.8 2.8
Barnyardgrass 4.0 0.9 22.5 0.1 3.0 <0.1 1.5 2.5
Field bindweed 4.0 0.7 17.5 0.2 4.3 <0.1 2.8 2.5
Marshelder 2.0 1.0 50.0 0.1 5.9 <0.1 1.5 2.0
Wild-proso millet 3.0 0.7 23.3 0.1 3.2 <0.1 1.7 1.9
Horseweed 2.0 0.8 40.0 0.2 8.6 <0.1 3.5 1.9
Sweetclover 4.0 0.4 10.0 <0.1 1.1 <0.1 1.0 1.9
Flixweed/Tansy mustard 3.0 0.6 20.0 0.1 2.2 <0.1 1.0 1.8
Venice mallow 1.0 0.6 60.0 0.3 31.2 <0.1 9.0 1.7
Curly dock 3.0 0.5 16.7 0.1 2.2 <0.1 1.3 1.7
Prostrate pigweed 3.0 0.5 16.7 0.1 2.2 <0.1 1.3 1.7
Russian thistle 2.0 0.5 25.0 0.1 3.2 <0.1 1.5 1.3
Prickly lettuce 2.0 0.2 10.0 <0.1 1.6 <0.1 1.5 1.0
Yellow nutsedge 1.0 0.2 20.0 <0.1 4.3 <0.1 3.0 0.6
Hedge bindweed 1.0 0.2 20.0 <0.1 2.2 <0.1 1.0 0.6
Prairie wild rose 1.0 0.2 20.0 <0.1 2.2 <0.1 1.0 0.6
Field sandbur 1.0 0.1 10.0 <0.1 2.2 <0.1 2.0 0.5
Swamp smartweed 1.0 0.1 10.0 <0.1 2.2 <0.1 2.0 0.5
Annual smartweed 1.0 0.1 10.0 <0.1 1.1 <0.1 1.0 0.5
Erect knotweed 1.0 0.1 10.0 <0.1 1.1 <0.1 1.0 0.5
Perennial sowthistle 1.0 0.1 10.0 <0.1 1.1 <0.1 1.0 0.5
Stinkgrass 1.0 0.1 10.0 <0.1 1.1 <0.1 1.0 0.5
Corn 1.0 0.1 10.0 <0.1 1.1 <0.1 1.0 0.5
Weed free 85.9 30.6 35.6 - - - - -
 

Table 79. North Dakota weed infestations in current crop of sunflower based on 158 surveyed fields, summer 2000.

        Weed  
  Weed Field Uniformity Weed Density Density Range