Control Measures 211 



out, after which the potatoes may be handled as any 

 other treated tubers. The following recommendations 

 should be observed by those using this method. Make 

 the treatment before the potatoes sprout. Place the 

 generating pan so that no potatoes are within three feet 

 of it and none directly above it. Use at least 167 bushels 

 of potatoes for each 1000 cubic feet of space or injury 

 will result to the tubers. This injury shows as a pitting 

 about the lenticels. Do not attempt treatment when the 

 temperature of the room is below 50° F. It is most 

 affective at 80° F. Thoroughly wet the floor of the dis- 

 infecting room with boiling water just before adding the 

 formaldehyde to the permanganate, as moisture in the air 

 of the room is very essential for effective work. Do not 

 attempt to treat potatoes in sacks or piled high in bins. 



The question often arises as to whether the crates or 

 bags in which the tubers are to be carried to the field 

 should be sterilized or whether cutting-knives should be 

 often disinfected. It is possible for spores of the organ- 

 isms causing potato diseases to be carried on containers 

 or implements and later come in contact with the tuber 

 under such conditions that infection may take place. 

 The writer is of the opinion that infection in this manner 

 does not frequently take place, but if one desires to avoid 

 every possible contamination, this disinfection will be 

 necessary. It may even be desirable when such diseases 

 have been very troublesome, but ordinarily it is not neces- 

 sary, although one should use judgment in the matter. 



If potatoes are cut more than a few days in advance of 

 planting, they should be dusted to prevent decay from 

 the action of saprophytic bacteria under favorable con- 

 ditions of heat and moisture. While other kinds of dust 

 will prevent the decay, flowers of sulphur is preferable as 



