IMPURITIES AND ADULTERATIONS

A foremost source of danger and loss, aside from infertile seed, is impurities and adulterants in the alfalfa seed planted. Growers often are careless and do not examine their alfalfa before or at the time of harvesting, and do not reclean their seed after threshing, thus sending out among innocent purchasers seed mixed with those of weeds, inferior grasses and forage plants, and with various trash which adds bulk and weight but has no value. The commonest seed adulterants or impurities are those of Sweet clover (Melilotus alba) ([Illus.] opp. p. 26), Bur clover (Medicago denticulata), Spotted clover (Medicago Arabica) ([p. 67]), Yellow trefoil or Hop clover (Medicago lupulina) ([p. 26]), and the Dodders (Cuscuta epithymum and Cuscuta arvensis), ([pp. 45] and [47]).

Yellow Trefoil Pods

The pods of Yellow trefoil are shaped as here shown and contain but a single seed. Magnified four diameters

Alfalfa Seed Pods

Alfalfa has a spiral pod of two or three turns, often containing five or six seeds. Magnified four diameters

Sweet Clover Pods

Magnified four diameters

Bur Clover Seed Pods

The seeds are enclosed in a coiled pod which is covered with bristly projections as shown above. Magnified four diameters

That an extraordinary proportion of the alfalfa seed in the markets, wheresoever from, is adulterated to an amazing extent with seeds of undesirable plants or loaded with worthless, if not actually harmful impurities, is being demonstrated by the United States Department of Agriculture. In a circular pertaining to this work is given the following, showing the adulterants found in samples bought in the open markets of the cities named:

	Seeds used as adulterants.
City where bought	Sweet clover		Bur clover		Yellow trefoil		Total adul- terants
	Per Cent		Per Cent		Per Cent		Per Cent
Providence, R. I.	....		3	.47	32	.86	36	.33
Denver, Colo.	....		16	.86	....		16	.86
Rochester, N. Y.	....		5	.02	39	.48	44	.50
Milwaukee, Wis.	....		5	.74	....		5	.74
Indianapolis, Ind.	....		4	.27	38	.43	42	.70
Indianapolis, Ind.	....		3	.90	39	.53	43	.43
Marblehead, Mass.	....		3	.00	....		3	.00
Petersburg, Va.	....		....		1	.25	1	.25
Cedar Rapids, Iowa	....		5	.49	....		5	.49
Indianapolis, Ind.	....		3	.37	38	.54	41	.91
Pittsfield, Mass.	9	.52	....		....		9	.52
Atlanta, Ga.	....		10	.04	....		10	.04
Salem, Ill.	....		....		6	.98	6	.98
St. Paul, Minn.	....		....		31	.77	31	.77
Louisville, Ky.	....		16	.53	....		16	.53
New Haven, Conn.	....		5	.88	39	.85	45	.73
Independence, Iowa	....		12	.69	....		12	.69
New Orleans, La.	....		2	.57		.63	3	.20
Troy, N. Y.	....		6	.23	31	.26	37	.49

In Farmers’ Bulletin No. 194 of the United States Department of Agriculture is given the [table] on page 34 to show the result of analyses of alfalfa seed imported within a period of six months.

Laboratory test No.	Alfalfa seed		Broken seed and dirt		Weed seeds		Number of weed seeds in 1 pound	Number of dodder seeds in 1 pound	Alfalfa seed that’ll grow		Amount imported
	Per Ct.		Per Ct.		Per Ct.				Per Ct.		Pounds
21000	93	.38	5	.8	0	.82	2,160	....	63	.73	4,000
21001	92	.1	7	.34		.56	900	....	59	.17	30,800
21002	82	.28	15	.92	1	.8	3,060	....	66	.64	5,500
21003	84	.72	11	.58	3	.7	3,420	....	57	.39	32,877
21004	89	.16	8	.78	2	.06	2,700	90	62	.18	14,700
21005	74	.06	21	.38	4	.56	15,928	2,520	53	.87	7,613
21006	58	.74	34	.46	6	.8	32,420	5,490	28	.78	33,075
21007	86	.12	11	.34	2	.54	8,964	270	61	.36	8,779
21008	73	.02	22	.32	4	.66	12,829	90	49	.65	32,963
21009	96	.82	2	.72		.46	990	....	85	.2	33,000
21010	86	.2	12	.1	1	.7	3,060	....	55	.59	30,800
21011	96	.96	2	.16		.88	1,710	....	87	.26	5,500
21012	88	.84	3	.98	7	.18	17,299	....	43	.2	33,000
21013	96	.24	2	.66	1	.1	3,510	....	77	.47	21,340
21014	91	.06	5	.44	3	.5	7,650	....	62	.14	8,778
21015	93	.44	2	.7	3	.86	8,526	....	77	.08	33,000
21016	77	.78	16	.04	6	.18	16,435	360	47	.83	33,000
21017	81	.52	12	.18	6	.3	21,848	720	7	.13	16,280
21018	69	.48	23	.78	6	.74	23,082	810	5	.21	38,172
21019	96	.5	3	.04		.46	1,080	....	88	.53	44,000
21020	96	.4	2	.82		.78	1,260	....	91	.82	44,000
21021	94	.4	5	.04		.56	1,620	....	90	.15	72,600
21022	24	.5	70	.96	4	.54	21,070	4,950	6	.34	12,540
21023	94	.14	1	.8	4	.06	3,780	....	73	.43	234
21024	94	.58	3	.44	1	.98	3,060	....	51	.78	5,500
21031	87	.72	11	.02	1	.26	4,140	90	81	.14	143,000
21032	90	.56	8	.08	1	.36	3,420	....	76	.29	33,000
21033	89	.04	10	.5		.46	1,260	90	84	.7	6,673
21035	72	.36	27	.1		.54	270	....	64	.58	13,516

Bearing also upon the adulterations, impurities and defectives found in alfalfa seed sold in the markets, extracts from reports of tests made at the Wooster, Ohio station (Bul. No. 142) are exceedingly interesting. In fifteen samples bought, each of one dollar’s worth, the quantity of pure germinable seed was found to range from 5.1 to 9.3 pounds; the number of noxious seeds found in a dollar’s worth of that bought as alfalfa seed ranged from 360 to 185,940. Seven of the fifteen one-dollar samples each carried more than 23,000 noxious seeds.

Seed bought at $7.80 per bushel showed as low as 61.2 per cent that was germinable, of which the actual cost was $12.74 per bushel. None of the fifteen samples had less than 77 per cent of germinable seed. One pound sample contained 21,728 noxious seeds, of which 18,144 were lamb’s-quarter or pigweeds; the same pound also had 3126 seeds of dodder. Another pound carried 6420 seeds of crab grass, and one had 3325 seeds of foxtail.

The station authorities recommend that no alfalfa seed be sown until carefully screened through a screen fine enough to remove dodder seeds. Wire sieves or screens with twenty meshes to the inch are found to serve the purpose.