52 



ELEMENTS OF AGRICULTURE 



50. Purity and Germination Test. For a more careful 

 test, a sample is weighed. It is then separated into: (1) 

 pure seed; (2) inert matter dirt, broken seed, etc.; (3) 

 weed seed. Each of these is weighed. The germinating 

 power of the pure seed is then found. The per cent of purity 

 multiplied by the per cent of germination gives the per 

 cent of live or viable seed. If a sample of alfalfa seed con- 

 tains 90 per cent of pure seed, and 90 per cent of this 

 germinates, it contains 81 per cent of viable seed. 



51. What is the Cheapest Seed. The cheapest seed 

 is usually the most expensive. The following analyses 

 show the extremes of low-grade, low-priced red clover 

 seed, and high-grade, high-priced seed: 1 



The seed that could be purchased for $5.20 per hun- 

 dred pounds was nearly twice as expensive as the seed 

 that cost $15 per hundred, because it contained so little 

 live seed. The low-grade seed should not have been sown 

 at any price, because of the weed seeds. If one sowed such 

 seed at the usual rate of sowing, he would not only fail 

 to get a good stand of clover, but would be sowing weeds. 



1 Farmers' Bulletin No. 260 



