July 15, 1920 



Presoak Method of Seed Treatment 



371 



Using a 6-hour presoak followed immediately by a 6-hour treatment 

 with formalin i to 400, 6 experiments were carried on in the greenhouse 

 with 23,700 seeds of nine varieties, the test for each variety being re- 

 peated several times. Table IV and figure i show the data obtained on 

 the sixth day after planting in each test, this date being chosen as showing 

 not only the relative percentage of germination but particularly revealing 

 any retardation or acceleration. At the same time, the effect of this 

 method on the blackchaff bacteria was determined, as discussed later. 



Table IV. — Effect of 6 hours' presoaking followed by formalin i : 400 treatment on 



germination of wheat seed 



Treatment. 



Control 



Formalin 1:400 for 10 minutes, 

 covered 12 hours 



Water for 10 minutes, covered 6 

 hours, formalin i: 400 for lomin- 

 utes, covered 6 hours 



Average percentage of germination. 



Marquis. 



Exp. 



V. 



Exp. 

 VI. 



82 

 54 



61 



Exp. 

 VII. 



Aver- 

 age. 



82 

 62 



73 



China. 



Exp. 

 V. 



52 

 44 



50 



Exp. 

 VI. 



38 

 34 



44 



Aver- 

 age. 



45 

 39 



47 



Turkey. 



Exp. 

 V. 



60 

 60 



71 



Exp. 

 VI. 



61 



52 



50 



Aver- 

 age. 



61 

 56 



61 



Treatment. 



Control 



Formalin i : 400 for 10 minutes, covered 6 

 hours 



Formalin i : 400 for 10 minutes, covered 12 

 hours 



Water for 10 minutes, covered 6 hours, forma- 

 lin I : 400 for 10 mintites, covered 6 hours . 



Average percentage of germination. 



71 

 61 



57 



71 



