6 
Colorado Experiment Station 
TKST No. ditch No. 1. 
Date, June 1, 1018. Duration, 20 min. 
Species of weed seeds, 9. 
Number of seeds, 20. 
Amaranth-us blitoides 5 
Amaranthus retroflexus 2 
Chenopodium album 1 
Polyg-onum aviculare 1 
Polygonum convolvulus 1 
Rumex crispus 6 
Taraxacum officinale 2 
Teucrium occidentale 1 
Grindelia squarrosa 1 
TEST No. 5. DITCH No. 2. 
Date, June 2, 1918. Duration, 180 min. 
Species of weed seeds, 14. 
Number of seeds, 168. 
Amaranthus blitoides 13 
Amaranthus retrofiexus 5 
Chenopodium album 78 
Iva xanthifolia 11 
Polygonum aviculare 11 
Polygonum convolvulus 12 
Polygonum persicaria 1 
Rumex crispus 6 
Taraxacum officinale 12 
Teucrium occidentale 15 
Grindelia squarrosa 1 
Salvia species 1 
Ambrosia trifida 1 
Franseria tomentosa 1 
TEST No. 8. DITCH No. 2. 
Date, June 3, 1018. Duration, 180 min. 
Species of weed seeds, 16. 
Number of seeds, 129. 
Salvia species 1 
Ambrosia trifida 1 
Solanum rostratum 1 
Amaranthus blitoides 13 
Amaranthus retrofiexus 4 
Carex species 1 
Chenopodium album 21 
Iva xanthifolia 10 
Iva ciliata 1 
Polygonum aviculare 7 
Polygonum convolvulus 2 
Polygonum persicaria 2 
Taraxacum officinale 61 
Verbena hastata 2 
Ambrosia artemisaefolia 1 
Malvastrum coccineum 1 
TEST No. 10. DITCH No. 1. 
Date, June 3, 1018. Duration, 180 min. 
Species of weed seeds, 9. 
Number of seeds, 1,039. 
Amaranthus blitoides 27 
Amaranthus retroflexus 25 
Carex species 6 
Chenopodium album 22 
Iva xanthifolia 16 
Polygonum aviculare 9 
Rumex crispus 3 
Taraxacum officinale 930 
Polygonum dumetorum 1 
TEST No. 13. DITCH No. 2. 
Date, June 5, 1018. Duration, 1,440 min. 
Species of weed seeds, 7. 
Number of seeds, 64. 
Amaranthus blitoides li 
Amaranthus retroflexus 9 
Carex species 6 
Iva xanthifolia 4 
Polygonum aviculare 3 
Rumex crispus 1 
Taraxacum officinale 30 
TEST No. 15. DITCH No. 2. 
Date, June 5, 1918. Duration, 1,440 min. 
Species of weed seeds, 10. 
Number of seeds, 84. 
Amaranthus blitoides 7 
Carex species 5 
Chenopodium album 21 
Iva xanthifolia 9 
Polygonum aviculare 3 
Polygonum convolvulus 2 
Rumex crispus 1 
Taraxacum officinale 34 
Grindelia squarrosa 1 
Verbena stricta 1 
TEST No. 10. DITCH No. 1. 
Date, June 5, 1018. Duration, 1,080 min. 
Species of weed seeds, 14. 
Number of seeds, 149. 
Amaranthus blitoides 13 
Amaranthus retroflexus 12 
Carex species 18 
Chenopodium album 11 
Iva xanthifolia 11 
Polygonum aviculare 11 
Polygonum convolvulus 1 
Polygonum persicaria 2 
Rumex crispus 1 
Taraxacum officinale 65 
Grindelia squarrosa 1 
Ranunculus species 1 
Ambrosia artemisaefolia 1 
Echinochloa crus-galli 1 
