162 



FORAGE PLANTS AND THEIR CULTURE 



care in this process more than anything else injures the 

 quality of the seed. Pieters and Brown found that freshly 

 gathered seed when put in ricks would heat to a tempera- 

 ture of 130 to 140 degrees in less than 16 hours, and that 

 this temperature would entirely destroy the vitality in 

 16 hours or less. 



The 'seed is mostly cleaned at warehouses with special 

 cleaning machinery. The yield averages about 15 bushels 



per acre, and 25 bush- 

 els is the maximum. 



At the Kentucky Ex- 

 periment Station, seeds 

 were gathered every 

 day or two in June 

 from the time the first 

 ripened. Germination 

 tests gave poorer re- 

 sults for those gathered 

 very early and very 

 late, the best being 

 FIG. 14. Mixture of seeds of Ken- those harvested be- 



tucky blue-grass (a) and Canada blue- tween June 14 and 

 grass (b). The Kentucky blue-grass seeds j _ K 

 are broadest at the center, pointed and June Zo. 

 have a distinct ridge on each side. Canada 151. Seed. Ken- 

 blue-grass seed are mostly broadest near 111 i 

 one end, blunt and smooth on the sides. tucky blue-grass Seed 



is frequently adulter- 

 ated with the cheaper Canada blue-grass (Fig. 14). This 

 is always an adulteration, as the former matures several 

 weeks before the latter. Pure Kentucky blue-grass is 

 brownish-straw in color, in the bulk considerably darker 

 than Canada blue-grass seed. The percentage of chaff 

 varies greatly, according to the methods of cleaning used, 

 but the best seed has 10 to 20 per cent of chaff. 



