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170 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 6, 1919] 



corn, and peas, merely dipped in water — after disinfection— 

 and then once in a dilute suspension of Bacillus mycoides be 

 fore being placed on agar for germination, showed 100 pei 

 cent of contamination after repeated trials. Possible difficul 

 ties with the salts of heavy metals were not tested. 



Definite experiments are under way to test the value of cer 

 tain commercial hypochlorites in the disinfection of seed foi 

 agricultural purposes. 



Summary Recommendation 



As a practical result of the experiments on seed treatment 

 reported it is believed that, taking into consideration both 

 (1) the capacity of the seed for germination after treatment 

 and (2) the relative freedom from contamination by micro- 

 organisms, the commercial "chlorinated potassa," or Javel 

 water, is the most satisfactory agent which has yet been con- 

 sidered. The length of time required for practically perfect 

 disinfection of certain seed in our experiments, with concen- 

 trations of 10-20 per cent, is 3 hours or longer. In some cases 

 interrupted disinfection fully warrants the extra trouble and 

 delay. The value of soaking the seed previous to the longer 

 interval treatments is doubtful. Nevertheless, a preliminary 

 thorough washing of all seed, with removal of decayed and 

 imperfect ones, is advisable. A study of standardized hypo- 

 chlorites is essential. 



