954 



EXPERIMENT STATION RECORD. 



error. The kind of seed bed, ventilation, evolution of oxygen, temper- 

 ature, light, and duration of the test are all stated as of great impor- 

 tance in seed testing. 



The methods for purity examination are considered at considerable 

 length and a form of apparatus designed to assist in this determination 

 is figured and described. 



The kind of seed bed, especially when testing grass seeds, is shown 

 to be of great importance, examples being quoted in which the germi- 

 nation of samples of grass seed averaged 06 per cent for the Nobbe 

 apparatus, 91 for filter paper, and 44 for open earth. 



The influence of temperature on germination is shown. For some 

 grasses, as well as for beet, carrot, and other seed, a constant tempera- 

 ture of 30° 0. seems to be the best. This is in direct opposition to the 

 regulations of the German Seed Control, as they recommend 30° C. for 

 6 hours daily, after which the thermostat is to be kept at about 20° C. 

 Of the species of seed recommended to be so treated the authors 

 report tests of Agrostjs, Aira, Glyceria, Holcus, Poa, Dactylis, beet, and 

 carrot seed, in which from 7.5 to 2(! per cent higher germinations were 

 secured when the higher temperature was maintained throughout the 

 experiments. 



The importance of a sufficient supply of oxygen and the proper amount 

 of moisture in the seed bed is pointed out. The results of a number of 

 experiments in which there was an insufficient supply of oxygen are 

 tabulated, in which the deficiency attributed to this cause varied from 

 1.5 to 50 per cent. The preliminary soaking of ordinary seed before 

 placing them in the seed bed is without ultimate effect, although seeds 

 with hard seed coats may be benefited by a brief soaking in hot water. 



The effect of light on the germination of seeds is commented upon 

 and in the case of seed of Poa spp. it exerts a very beneficial effect, as 

 is shown in the following table. All seed were germinated in thermostats 

 at a temperature of 30° C, the comparisons being made of seed from 

 the same lots. 



Effect of light o>t germination of grass seed. 



Poa pratensis 



Poa pratensis (old seed). 



Poa trivialis 



Poa nemoralis 



Poa nemoralis (old seed) 



In dark- 

 ness. 



Per cent. 

 8.25 

 3.50 

 13. 00 

 14.25 

 8.00 



The authors describe in considerable detail their method for germi- 

 nating grass seed, for which purpose they prefer a seed bed of filter 

 paper. Sand seed beds are also described. 



The question as to the proper duration of a test of seed is considered 

 and numerous examples are cited in which the time usually given is 

 shown to be too short. 



