SEEDS ANY) SEEDLINGS 163 



After the rest period the time required for germination 

 varies greatly, drains, grasses, and many seeds of herbs of 

 the Pea family germinate in from two to eight days, and seeds 

 of most plants of the Parsley family in about fourteen days. 

 The seeds of the hornbeam and ash are said not to grow 

 until the second spring after they are planted. 



154. Seed testing. In growing crops from the seed it is 

 desirable to use only seed of the highest quality. The seed 

 should be of one of the best varieties, that is, a choice kind 

 of grain, beet, tomato, or other plant, which is adapted to 

 the soil and climate of the region. 1 Good seed is pure and 

 of high vitality. Purity means freedom from earth, sticks, 

 broken seeds, bits of leaf, or weed seeds. High vitality 

 means a large percentage of vigorous live seeds which, under 

 good conditions, will grow. The purity can be tested by exam- 

 ining a small average sample of the seed with a good lens and 

 separating the sound seeds of the desired plant from foreign 

 seeds and other impurities. The vitality can be tested by 

 sprouting a convenient number of seeds, one lot from each 

 sample to be examined. Place the counted seeds on mois- 

 tened blotting paper in a plate and cover them with an in- 

 verted plate. If many seeds fail to grow, it is because (1) the 

 seeds have been kept too long and have lost their vitality ; 

 (2) the seeds have been exposed to too great heat or moisture, 

 or to too sudden changes in temperature ; (3) the seeds were 

 immature or otherwise imperfect when collected. The use of 

 impure seeds or those of low vitality is extravagant, no matter 

 how cheaply they were bought, as impure seeds may introduce 

 many bad weeds, and seeds of low vitality will not give a good 

 stand of the grain or other crop planted. 2 



1 See Chapter XII. 



2 The teacher can usually secure a bulletin on seed testing from the 

 agricultural experiment station of his state. 



See also Lyon and Montgomery, Examining and Grading Grains, Ginn 

 and Company, Boston ; Burkett, Stevens, and Hill, Agriculture for Begin- 

 ners, Ginn and Company, Boston ; and Warren, Elements of Agriculture, 

 The Macmillan Company, New York. 



