Irrigation Water 
9 
Chenopodium album 40 
Grindelia squarrosa 2 
Iva xanthifolia 13 
Polygonum aviculare 14 
Polygonum convolvulus 4 
Rumex acetosella 3 
Cleome serrulata 1 
Taraxacum officinale 4 
Teucrium occidentale 1 
Polygonum engelmanii 1 
Grindelia squarrosa 4 
Urtica gracilis 3 
Verbena hastata 18 
Ranunculus species 2 
Solanum rostratum 1 
Helianthus annuus 1 
Geranium species 3 
Portulaca oleracea 3 
Polygonum engelmanii 2 
Capsella bursa-pastoris 3 
Avena saliva 1 
TEST No. 54. DITCH No. 1. 
Date, June S6, 1918. Duration, 369 min. 
Species of weed seeds, 4. 
Number of seeds, 16. 
Amaranthus retroflexus 2 
Carex species 4 
Chenopodium album 5 
Polygonum aviculare 5 
TEST No. 57. DITCH No. 2. 
Date, June 26, 1918. Duration, 360 min. 
Species of weed seeds, 16. 
Number of seeds, 518. 
Amaranthus blitoides . . 
Amaranthus retrofiexus 
Carex species 
Chenopodium album . . 
Iva xanthifolia 
Polygonum aviculare . . 
Polygonum convolvulus 
Polygonum persicaria . 
Geranium species 
Portulaca oleracea .... 
Rumex crispus 
Taraxacum officinale . . 
Urtica gracilis 
Verbena hastata 
Polygonum engelmanii 
Lappula occidentale . . . 
46 
111 
51 
107 
2 
19 
14 
2 
3 
4 
5 
2 
3 
145 
1 
3 
TEST No. 71. DITCH No. 1. 
Date, July 30, 1918. Duration, 1,080 min. 
Species of weed seeds, 6. 
Number of seeds, 24. 
Amaranthus blitoides 5 
Chenopodium album 5 
Grindelia squarrosa 1 
Iva xanthifolia 1 
Polygonum aviculare 4 
Rumex crispus 8 
TEST No. 72. DITCH No. 1. 
Date, Aug. 13, 1918. Duration, 1,440' min. 
Species of weed seeds, 6. 
Number of seeds, 18. 
Amaranthus blitoides 4 
Amaranthus retroflexus 1 
Polygonum aviculare 4 
Polygonum convolvulus 4 
Rumex crispus 4 
Sonchus asper 1 
TEST No. 74. DITCH No. 1. 
Date, July 29, 1918. Duration, 480 min. 
Species of weed seeds, 3. 
Number of seeds, 3, 
Amaranthus blitoides 1 
Carex species 1 
Polygonum aviculare 1 
TEST No. 62, DITCH No. 1. 
Date, July 2, 1918. Duration, 360 min. 
Species of weed seeds, 23. 
Number of seeds, 377, 
Amaranthus blitoides 47 
Amaranthus retroflexus 108 
Carex species 41 
Chenopodium album 82 
Iva xanthifolia 7 
Polygonum aviculare 31 
Polygonum convolvulus 2 
Polygonum persicaria 4 
Rumex crispus 5 
Stellaria media 3 
Taraxacum officinale 5 
Teucrium occidentale 1 
TEST No. 75. DITCH No. 1. 
Date, July 31, 1918. Duration, 1,440 min. 
Species of weed seeds, 2. 
Number of seeds, 2. 
Amaranthus blitoides 1 
Rumex crispus 1 
TEST No. 76. DITCH No. 3. 
Date, July 26, 1918. Duration, 1,440 min. 
Species of weed seeds, 6. 
Number of seeds, 7. 
Amaranthus retroflexus 1 
Chenopodium album 2 
Rumex crispus 1 
Ambrosia triflda 1 
Iva xanthifolia 1 
Verbena hastata 1 
