4 N. H. EXPERIMENT STATION [Bulletin 215 



should not be satisfied with an equal amount of seed ma- 

 terially lower in purity or germination. (Small seeds like 

 the grasses and clovers cannot be cleaned absolutely pure 

 by commercial mechanical means although they may run 

 very nearly perfect in the best grades of many varieties. 

 Larger seeds like corn and beans may easily be practically 

 100 per cent pure.) If seed were only 80 per cent pure 

 and gave a response of only 70 per cent in germination, 

 it might still be useful provided the buyer was satisfied that 

 it contained no harmful materials like injurious weeds and 

 that the purchase price was comparable to the actual pro- 

 portion of good seed present. The farmer's ten pounds of 

 seed which was 98 per cent pure actually had 9.8 pounds 

 of the kind of seed he wanted. If 99 per cent of that 

 would germinate, he could expect 9.7 pounds of his pur- 

 chase to start to grow under proper conditions. In the 

 second case, only 8 pounds out of the 10 will be red clover 

 and only seventy seeds in a hundred will properly germi- 

 nate. Therefore, with this seed one could expect a response 

 from only 5.6 pounds out of the original 10. Disregarding 

 probable danger from weed seeds and the possibility of less 

 vigorous plants from the clover seed that actually responds 

 with healthy appearing sprouts, this material could be worth 

 only a little more than half as much as the better sample. 

 Apparent percentages are sometimes misleading. The agri- 

 cultural value of a sample of seed for planting is onl}- as 

 good as the product of its purity and germination percent- 

 ages. 



On the tag accompanying the seed should be found 

 the date when the last germination test was made. This 

 is required by law. Merchants should keep in mind that 

 seeds deteriorate from year to year and that guarantees 

 made by the wholesaler may not conform to the actual con- 

 ditions of the seed if more than a year old. Some of the 

 most flagrant violations of the seed law have been traced 

 to just such a situation. 



