Testing Farm Seeds. 



383 



scales (tig. 30, a and b) aud pieces uf stems, leaves and other inert ma- 

 terials. Many samples of cliafif:* redtop contain very little solid seed. 



The recleaned grade is usually comparatively free from impurities, 

 but sometimes contains timothy to the extent of severe adulteration, and 

 so should be tested in this respect. 



In making a practical test of the unhulled and chaff grades of red- 

 top the .lightest chaff may be blovs^n carefully from the heaviest seed of a 

 quantity of seed of knov^^n weight. Some seeds veill retain the inclosing 

 outer chaff, giving them the appearance shown in figure 30, a. Slight 

 rubbing will loosen this outer chaff, when it, too, may be blown away, 

 leaving the pure seed in essentially the same condition as shown in the 

 recleaned grade. This seed, after removing the ergot, timothy, and other 

 foreign seeds, may then be weighed and its quantity compared with the 

 quantity of the original test sample. Such a comparison sometimes shows 

 a surprisingly small quantity of true seed in chaffy grades. 



The purity of commercial redtop 

 seed is evidently dependent on the 

 trade grade and the extent to 

 which the grades are cleaned. The 

 solid or recleaned grade should 

 show a purity of 95 to 98 per cent. 

 The germination should be as high. 

 The unhulled grade is more vari- 

 able both as to purity and viabili- 

 ty. The purity is influenced by 

 the widely variable quantity of 

 broken leaves, ergot, and loose 

 chaff, and the viability varies be- 

 cause of the practically worthless 

 immature and undeveloped grains which constitute a variable proportion 

 of this grade of seed. 



The noxious weed seeds found in redtop (cliiefly in the chafify grades) in- 

 clude: . (Fig. 17) doclc (f); (fig. 18) tumbling mustard (c), rat-tail plantain (1), 

 buckhorn (m), oxeye daisy (q). 



The commoner of the other weed seeds found in redtop seed include: 

 (Fig. 19) crab-grass (a), witch-grass (b), sedge (g), lamb's-quarters (1), chick- 

 weed (r); (fig. 20) peppergrass (b), shepherd's purse (c), cinquefoil (d) ; (fig. 

 21) black-eyed Susan (1), dog fennel (m), field camomile (n). 



Fig. 30. — Chaff of redtop seed : a, Whole 

 spikelets usuaHy devoid of seed in 

 "chaffy" grades ; b, separated scales 

 of the same; a and b represent the 

 outer chaff of the seed. (Enlarged.) 



TESTING AWNLESS BROME-GRASS SEED. 



Both domestic and imported seed of awnless brome-grass {Brormis 

 inermis) is in the American market. This seed should be readily recog- 



