1919] 



DUGGAR AND DAVIS — SEED DISINFECTION 



167 



TABLE V 



DISINFECTION OF SEED (AFTER IMMERSION IN WATER FOR 4 HOURS AT 23°C.) BY 



SODIUM HYPOCHLORITE. FINAL OBSERVATIONS AFTER 96 HOURS 







Interval of 







Kind of seed 



% Concen- 



treatment, 



% Germi- 



• 



% Contami- 



• 



* m- A I IV^l \_J k ^VVVi 



tration 



hours 



nation 



nation 





10 



2 



96 



2 





10 



1 



86 



30 



Corn 



10 

 5 



1 



3 



92 

 90 



4 

 





5 



2 



92 









5 



1 



90 







26 



44 





10 



2 



35 





10 



1 



30 



96 



Peas 



10 



5 



i 



3 



58 

 40 



52 

 58 





5 



2 



28 



30 





5 

 10 



1 



2 



30 

 88 



20 





50 





10 



1 



96 



72 



Cucumber 



10 



5 



J 



3 



92 

 92 



100 

 30 





5 



2 



82 



14 





5 



1 



94 



98 





10 



2 



26 



58 





10 . 



1 



18 



10 



Radish 



10 



5 



3 



46 

 46 



14 

 6 





5 



2 



24 



2 





5 



1 



26 



4 



than 2 per cent when 12 plates of about 30 seed each were 

 sown. At the same time small quantities (2 dishes each) of 

 lettuce, navy beans, and lima beans were similarly treated, 

 with no contamination in any dish. 



It was suggested that discontinuous disinfection might 

 prove serviceable and practicable in work of this type, just 

 as discontinuous sterilization by heat is so effective. Accord- 

 ingly, experiments were arranged in which the dry seed were 

 treated for 2 hours in deep Petri dishes with 20 per cent Javel 

 water, then, after pouring this off, the seed were rinsed, and 

 finally left in an incubator at room temperature for 2 days. 

 The same treatment with rinsing was then repeated, and the 



placed for germination as in other 



The 



shown in table vn. and these indicate complete disinfec 



