SELECTION OF SEED ; FARM CROPS. 123 



both injurious and harmless, that may be present in the 

 seed purchased, as seeds not genuine, dirt, dust, weed-seed, 

 chaff, and diseased seed. The presence of weed-seed per- 

 haps results on the whole in the greatest loss and annoy- 

 ance, in the first place, the loss of return from land 

 taken up by the weeds, hence a reduction in crop; and 

 second, the difficulty and expense of eradicating the weeds 

 r when well established. 



Adulteration. Adulteration of seed includes, first, 

 the substitution of cheaper seed for the more valuable, 

 which is frequently practised in the case of mixed seeds 

 that resemble each other, and second, the removal of the 

 evidences of age or disease. Seed that are musty or dark 

 are sometimes sweetened and brightened by bleaching 

 with fumes of sulphur. 



Quality of Seed. The quality of genuine seed is 

 influenced by age, size, weight, and smell. Old seed are 

 less likely to germinate than new; the loss of vitality 

 is gradual, though more rapid in unripe than in well- 

 ripened seed ; the larger and heavier seeds also die more 

 slowly than the smaller and lighter ones. 



The seed of the cereals and grasses lose germinating 

 power and vigor rapidly after the first year ; though alive, 

 they germinate and grow slowly, thus causing a loss of 

 time at the beginning of the season, and the slow growth of 

 the plant at its most tender stage increases the tendency 

 to disease and insect attack. 



Seed may also be killed by a too rapid or too complete 

 removal of water from them ; hence artificial drying, if 

 improperly conducted, that is, if too great heat is used, 

 may result in the death of the germ. 



