ELEVENTH ANNUAL YEAR BOOK— PART XI 



747 



Fig\ 23. — Seeds of yellow trefoil; a, seeds showing 1 

 variation in form and size; b, natural size of 

 seeds; e, oval form of trefoil seeds indicated; d, 

 a pod of trefoil. 



and (3) miscellaneous screenings consisting of shriveled clover seed and 

 weed seeds, or of very small red clover seed indicating foreign production. 



Separate all true red clover seed, together with yellow trefoil present 

 in quantity sufficient to indicate intentional adulteration, from all weed 

 seeds and other materials. 



If the sample is adulterated with trefoil or other specific adulterant, 

 count out 1,000' seeds 

 from the clover and 

 adulterant freed from 

 other impurities and de- 

 termine the quantity of 

 the adulterant by count. 



The total quantity of 

 true red clover seed, in- 

 cluding shriveled seed, 

 is the "pure seed" of the 

 test; accurately record 

 its weight. The per- 

 centage of true red clo- 

 ver seed in the test 

 sample and in the original sample is shown by dividing this weight by the 

 weight of the original sample, expressing the result in per cent; or, if 

 seed equal to the weight of 121/.BB shot is being tested, each 1-16 shot 

 weight represents one-half of 1 per cent of the whole. 



Count indiscriminately from the pure seed 200 seeds in duplicate for 

 the germination test. Conduct this test as previously directed under "The 

 germination test." Sprouting should begin the second day and be com- 

 pleted by the sixth day. At the completion of the sprouting, examine 

 seeds which have not sprouted to determine whether they are hard 

 or soft. In general, the presence of a considerable quantity of hard seed 

 indicates that the sample is one of new seed. The hard seed may amount 

 to 20, 30, or even 50 per cent in red clover seed 1 year old. Although 

 such hard seed is probably all alive, it is practically worthless for seed- 

 ing. Soft seeds which do not sprout may be considered as dead before 

 the test was made. An excess of such seed indicates the use of old seed 

 as an adulterant. The best red clover seed tests as high as 98 or 99 per 

 cent purity and 99 per cent viability. 



The foreign seeds in red clover may include other crop seeds, as alsike 

 clover, white clover, or timothy. Note should be made of the presence, 

 character, and quantity of such crop seed. 



The weed seeds should be considered with respect to their total quan- 

 tity and their character as affecting the clover crop and the land. Seeds 

 of strictly noxious plants should be distinguished as well as those indi- 

 cating the domestic or foreign source of the seed. Rural school pupils, 

 especially, who make tests of seeds should be interested in identifying 

 so far as possible, the kinds of all the weed seeds found. 



The noxious weed seeds found in red clover seed include: Dock, black 

 bindweed, Russian thistle, white campion, bladder campion, night-flower- 



