ELEVENTH ANNUAL YEAR BOOK— PART XI 745 



Red clover and alfalfa seed are sometimes so slow in absorbing moist- 

 ure that the germination is delayed several days or even several weeks. 

 This is particularly true of new seed. The same seed a year later may 

 show a greatly reduced amount of this so-called "hard seed" and there- 

 fore a higher percentage of germination under test. Such seed remains 

 hard in the test when other seed has become soft by the absorption of 

 water. 



The time required for germination differs with different kinds of seed. 

 Between the times of appearance of the first and the last sprouts there 

 is a period of maximum germination when the practical germinating value 

 of the seed is evident. 



Determining the actual value of the seed. — The actual value of the 

 pure, germinable seed in a sample depends on its quantity, as compared 

 with the total weight of the sample. Assuming, for illustration, a stan- 

 dard of absolute purity and viability in seed selling at $10 per 100 pounds, 

 such seed is actually worth, at this rate, 10 cents per pound. On the 

 other hand, seed selling at the same price, but on test showing a purity 

 of 80 per cent and viability of 70 per cent, contains but 70 per cent of 

 80 per cent, or 56 per cent of pure, viable seed. At $10 per 100 pounds 

 of this seed as sold the good seed actually costs nearly 18 cents per pound. 



This ideal state of perfection in purity and viability of seed is rarely, 

 if ever, attained. It is important, however, to know the highest quality 

 that seed can justly be expected to show. It is fair that the best seed 

 that is marketed should serve as a guide in this respect, because the 

 average results of miscellaneous tests of any particular kind are too low, 

 since some samples are altogether too low in quality. The fact that seed 

 of the prinicipal forage crops in which both the purity and the viability 

 closely approach 100 per cent does appear on the market justifies one in 

 assuming that all seed of these crops sold as high grade should possess 

 equally good quality. 



The practical application of this understanding as to quality may some- 

 times admit of due allowance. For example, clover seed is sometimes 

 sold locally in the chaff. If such seed is known to be free from noxious 

 weed seeds, it can safely be purchased if proper allowance be made for 

 the proportion of worthless chaff and undeveloped seed. An average 

 sample of the chaffy seed may be weighed and its percentage of good 

 seed ascertained. Since clover seed weighs 60 pounds per bushel, the 

 actual value of such chaffy seed can readily he determined, the price reg- 

 ulated, and the quantity to be sown accurately gauged. 



The actual proportion of pure, viable seed in a sample is represented 

 by the product of its percentages of purity, a viability expressed in per 

 cent. 



