1919] 



DUGGAR AND DAVIS SEED DISINFECTION 



169 



TABLE VIII 



DISINFECTION OF SEED BY CHLORINATED LIME,— DISCONTINUOUS TREATMENT 



FINAL OBSERVATIONS AFTER 96 HOURS 



Kind of seed 



% Concen 

 tration 



Corn 



Peas 



Cucumber 



10 



*10 

 •10 



5 



*5 



*5 



10 

 *10 



*10 



5 



*5 



Interval of 



treatment, 



hours 



10 

 *10 



•10 



5 

 *5 

 *5 



1 



1 

 i 



2 



2 

 2 

 1 



1 



1 



i 



2 

 2 



1 



% Germi 



nation 



% Contami 

 nation 



1 

 1 



2 



2 



1 



Radish 



10 



no 

 no 



5 

 *5 

 *5 



1 



1 



4 



2 

 2 



1 



72 

 60 



100 

 56 



100 

 96 



20 

 52 

 24 

 16 

 60 

 40 





 

 



28 

 

 



8 

 

 50 

 100 

 

 4 



92 

 36 

 80 

 60 

 72 

 100 







8 

 14 





 



18 





 

 

 100 

 12 

 



12 



16 



100 



48 

 56 



t • # 



* In these cases the seed were soaked for 4 hours prior to treatment, while 

 in the other cases dry seed were treated. 



of contamination occurred, so that these and related sub- 

 stances were believed to be unsatisfactory for the purpose of 

 this study. 



Particular stress has been laid by de Zeeuw on the difficulty 

 of properly washing off the disinfectant. He argues that 

 quite commonly there may be transferred with the seed a suf- 

 ficient amount of the disinfectant to insure antiseptic action 

 during the germination of the seed on agar, but the unkilled 

 germs may develop later — when the seed are transferred to 

 final cultures. With the hypochlorites we have not been able 

 to detect any such possibility, even when intentionally making 

 the washing process less thorough than usual. Seed of beans, 



