718 



IOWA DEPARTMENT OF AGRICULTURE 



pi-rpo.se of seed tests. 



The purpose of making tests of farm seed is to detect the undesirable 

 conditions affecting the seed which have been referred to in preceding 



Fig. 11. — Mixture of seeds of awnless brome-grass (a), meadow fescue (b), 

 English rye-grass (ct, and chess, or cheat (A). The brome-grass seeds are 

 distinguished by their greater length and flattened form. The seeds of 

 chess («1) are somewhat cylindrical, due to being- folded lengthwise. They 

 are thus thicker than the awnless brome-grass seed and sometimes are 

 awned. (Enlarged.) 



paragraphs. Such tests should be made early enough in the season to 



allow ample time to obtain other samples or to buy additional seed if 



the tests lead merely to providing for foreign matter by sowing a larger 



Quantity of seed. 



The seed of most of the farm 

 crops can be recognized with cer- 

 tainty under careful examination 

 as to its particular kind. Seed 

 of different varieties of a kind 

 as a rule can not be distin- 

 guished in this way. For exam- 

 c pie, red clover seed can be dis- 

 tinguished from other seeds, but 

 the medium and mammoth va- 

 rieties of red clover can not be 

 distinguished by their seeds. 

 Seeds of varieties of individual 



kinds of plants usually must be grown to insure varietal determination. 



This is not a part of the usual seed test. 



The first object of the test, excepting with respect to varieties, is to 



find out if the seed is true to name. 



£** 



a 



Fig. 12. — Seeds of flax dodder (b double, 

 c sing-le) and of flax (a)., showing rel- 

 ative sizes. (Enlarg-ed.) 



