GERMINATION 23 



37. Temperature variations influence seeds in germina- 

 tion less than do those of moisture. Both, however, 

 should be avoided. Seeds will stand much heat and cold 

 if dry, but if wet, frost may injure them and heat may 

 "cook" them. In seed storage, everything promotive of 

 decay must be avoided. Especially must the seed be kept 



FIG. 17 GLASS PROTECTORS FOR OUTDOOR PLANTING 



At left, F, panes of glass fitted together by wooden top. At right, continuous 

 plant forcer: A, wire for ridge; a, b, outside; c, inside; B. wire to hold side panes 

 at d and e; C, making section; D, completed section; E, continuous row. 



as dry as possible. The room may be even hot, provided 

 it is not damp. This rule applies to small as well as 

 large quantities of seeds. Often corn, wheat and other 

 cereals improperly dried before shipment heat in transit 

 and are ruined both for seedage and food. Sometimes 

 the heat is great enough to cause great losses in ware- 

 houses and ships, in some cases even starting fires by 

 spontaneous combustion. 



38. Time of sowing out of doors, as well as depth, 

 influences temperature. Seeds planted deeply in spring 

 may rot because they are too cold ; and those planted 

 shallow in summer may continue dry and thus fail to 

 sprout. Hence early spring sowing of any kind of seed 

 should be shallower than that of the same kind in late 

 spring or summer. No general rule can be given, be- 



