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CHAPTER V. WEED IMPURITIES IN AGRICULTURAL SEEDS

A large number of weed seeds of different kinds occur in various commercial seeds. These weed seeds vary, depending on the character of the crop and locality where the commercial seed was grown. The foreign material in the seed is largely accidental. For instance, the Iowagrown clover seed contains pigeon grass, foxtail, smartweed and other weed seeds found in the Iowa clover meadow. Clover seed grown in Missouri will have a great deal of bracted plantain, while eastern-grown seed has much buckhorn. Alfalfa seed grown in Utah is likely to have dodder, black medic, etc. Minnesota-grown wheat is sure to have corn cockle and vetch, while seed oats from the same state may have quack grass. Mustard is certain to occur in Iowa-grown oats. The fault is not always with the seed merchant. The farmer demands a cheap seed and in doing so is likely to buy seeds that contain many weed seeds. It is always better to buy the better quality of seed. I knew of a case where the farmer was selling his neighbor red clover seed at $9 per bushel, when he could have bought good clover seed for a little more. Thirty-four per cent of the seed consisted of weed seeds and dirt. He was paying more for this seed than the best seed on the market was selling for.

The only way to buy seed is on a guaranty. It is an easy matter for the seed merchant to make a statement that his seed contains a given per cent of purity and is free from noxious weeds of a certain type. I believe most seed merchants are beginning to realize the importance of selling good seed. The matter of germination is so unreliable and the seed varies from year to year so much that very little that is definite can be given on this point. Impurities of Red Clover Seed.—The kind of impurities found in red clover seed varies somewhat with the locality, in which the clover is grown. In the United States the more common impurities reported are as follows: Rugel's plantain (Plantago Rugelii), green foxtail (Setaria viridis), lady's thumb (Polygonum Persicaria), lamb's quarter (Chenopodium album ), ribgrass (Plantago lanceolata), curled dock (Rumer crispus), yellow foxtail (Setaria glauca), sorrel (Rumer Acetosella), large spotted spurge (Euphorbia mutans), bracted plantain (Plantago aristata), timothy (Phleum pratense), witch grass (Panicum capillare), smooth crab grass (Digitaria humifusa), crab grass (D. sanguinalis), tumble weed (Amarantus albus), alsike clover (Trifolium hybridum), night-flowering catchfly (Silene noctiflora), blue vervain (Verbena hastata), mayweed (Anthemis Cotula), ragweed (Ambrosia artemisiaefolia), barnyard grass (Echinochloa crus-galli), white clover (Trifolium repens), wild pepper grass (Lcpidium virginicum), bull thistle (Cirsium lanceolatum), Canada thistle (Cirsium arvense), field dodder (Cuscuta arvensis), wild carrot (Daucus Carota), black mustard (Brassica migra), chicory (Chicorium Intybus), yellow trefoil (Medicago lupulina), five-finger (Potentilla monspeliensis), nimble will (Muhlenbergia meticana and glomerata). To illustrate the quality of seed in general use, the following statement of red clover seed, analyzed in Iowa, may be given : One hundred and thirty samples of weighed red clover were examined for impurities and adulteration, the average per cent of impurities was 1.93, the highest per cent was 33.2, only two samples consisted of pure seed. The following impurities were found in 255 samples of red clover seed in percentages, as follows: Timothy, 64.8; Canada thistle, 9.2; foxtail, 54.0; dodder, 4.0; bull thistle, 6.O; sheep Sorrel, 34.4; dock, 44.o, and others. Of the unweighed samples 63.8 per cent contained foxtail, 57.1 per cent timothy, 51 per cent curled dock, 47.8 per cent green foxtail, 38.6 per cent rib plantain, buckhorn, or ribgrass; 28.5 per cent sheep sorrel, and 11.9 per cent Canada thistle. Of the two hundred and fifty-five samples examined timothy was found in 162, sand and dirt I.38, yellow foxtail 135, green foxtail 128, curled dock IIo, sheep sorrel 86, bracted plantain 38, evening cockle 22, Canada thistle 24 and dodder Io. It will be seen from the above partial list that many bad weed seeds are found in clover seed. We found, further, that clover seed in some in

Fig. 27. Some impurities in red clover stances showed a very seed. 1, wild carrot; 2, buckhorn, two low vitality. Only four

views; 3, Canada thistle; 4, clover dodder; 5, green foxtail, two views; of the samples showed

feojo 7, bracted plantain, a vitality of 99 per cent and over. There was a considerable number below 80 per cent and twenty-one samples above. Impurities of White Clover Seed.—The more common impurities are sorrel mayweed, lamb's quarter, the plantains, dooryard knotgrass, night-blooming catchfly, fivefinger and chickweed. The following illustration is given of samples examined in Iowa: The impurities found in weighed samples of white clover were sheep sorrel, 44.4 per cent; plantain, 33.3; bracted plantain, 11.1; lamb’s quarter, 11.1. Of these the sheep sorrel, dock and plantain are bad weeds. In the unweighed samples sheep sorrel occurred in 80 per

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cent of the samples. Slightly different results have been obtained in other localities. The kind of impurity will depend on locality. Meadow Fescue: Common Impurities or.—Yarrow, Rugel's plantain, sedge, cinquefoil, chess or cheat, pepper grass, Sorrel, brome

© grass, orchard grass, velvet () 0. grass (quack grass a possi

bility), English ryegrass. (9 & Kentucky Blue Grass: Com- ds of red mon Impurities of.-The imo, i."... purities of Kentucky blue clover. (Hillman.) grass are practically the same as given for meadow fescue. although Kentucky blue grass may contain Canadian blue grass and English blue grass (meadow fescue). Alsike: Common Impurities of.-Timothy, sheep sorrel, lamb’s quarter, night-flowering catchfly, dooryard plantain, pigweed, pepper grass, red clover, wild clover, five-finger, crab grass, mayweed, curled dock, blue grass, hair grass. Alsike clover is not generally adulterated, but impurities were found as follows in Iowa: Sheep Sorrel, 86.1 per cent; plantain, 33.3 per cent; Canada thistle, 25 per cent; buckhorn or rib plantain, II. I per cent.

Alfalfa: Common Inn" purities of.-Green foxtail, yellow foxtail, red clover, bur clover, barnyard grass, yellow trefoil, crab grass, chicory, centaurea, alsike, sweet . Fig. 29. Impurities, in , alsike. 1, l ild ind alsike clover; 2, Rugel's plantain; 3, cover, wild rye, grin le- small pepper grass (Lepidium apelia, Rugel's plantain. talum); 4, sheep sorrel (Rumex Aceto

- - ities sella), with covering; 5, timothy The chief impurities hulled and unhulled; 6, sweet clover. found in alfalfa are (ö. M. King.)

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black medic, bur clover and sweet clover. The impurities found in samples examined in Iowa are alfalfa dodder, 4. I; knot weed, 4.1 ; rib grass or buckhorn, 62.5; cockle, 12.5; Canada thistle, 8.3; sheep sorrel, 4. I; plantain, 4.1 ; bracted plantain, 4.1 ; yellow foxtail, 33.1; curled dock, 8.3. Impurities in Orchard Grass.-The more important impurities found in orchard grass are. fescue grass (Festuca pratensis), velvet grass

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clover; 5, pod of sweet clover; 6, chicory; 7, spotted clover; 8, bur clover. (C. M. King.)

(Holcus lamatus), especially in New Zealandgrown seed; English rye grass (Lolium per

enne), blue pearl grass (Molinia caerulea), crested dog'stail (Cynosurus cristatus), dock (Rumer crispus), sheep sorrel (Rumer Acctosella), pepper grass (Lepidium apeta

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mint families had a prolonged vitality. Later Becquere! also made a study of the prolonged vitality of seeds, and he found of the 550

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