63 



method, however, has one important drawback ; it takes more time than 

 can often be allowed for the germination test, especially in the case of winter 

 rye, wheat and barley. Some experts therefore advise that after-ripening 

 should be done at a low temperature. This can be brought about by putting 

 the seed, previous to germinatioUj in an ice-box at a temperature of 3° to 6° 

 Centigrade, and bv germ.ination at a temperature varying between 8° and 

 15°; see Whitcomb (50), Toole (51), Harrington (7), Rose (52). Whitcomb 

 observes, e.g., " this method is especially well adapted to testing newly 

 threshed grains; a germination test by the ice-chest method of winter 

 wheat and other grains immediately after threshing will indicate the 

 percentage of seeds, in a given lot, which will produce healthy plants under 



FlGUBE 1. 



normal field conditions." Toole advises : " When a sample has failed to 

 give a good germination, the remainder may be transferred to the cold for 

 five days ; if the poor results have been due to dormancy, germination will 

 be completed after they are returned to the warm germinator." Atterberg 

 (46) and Qvam (53) recommend a germination temperature of 10° to 15°; 

 the "Technische Vorschriften fiir die Priifung von Saatgut" (54) recommend 

 one of 8° to 12°- Haltner (45) thinks a temperature of 13° to 15° best and, 

 if it fails to cause speedy germination, previous dr5dng at 40°. Heinrich (56) 

 observes that low temperatures quicken the germination of poorly after- 

 ripened seeds, but have a delajang influence when full ripeness has been 

 obtained. Harrington states the same thing and so recommends removing 

 any seed remaining ungerminated at the end of some days at a low tetti- 

 perature into germinating chambers at a higher temperature. In the new 

 " Rules for seed testing of the New York State Agricultural Experiment 

 Station " (68) we road : "in the ceise of cereals and timothy grown under 

 such conditions that they are frosted or exposed to cold weather before 

 harvest, the germination tests should be made at lower temperatures. 



