Propagation 



61 



potatoes has been practiced, much may be accomplished 

 toward preventing trouble in the seed-bed by dipping 

 the seed from five to 

 eight minutes in a solu- 

 tion made by dissolving 

 1 ounce of corrosive 

 sublimate in 8 gallons 

 of water. (Fig. 6.) 

 An old lard or molasses 

 barrel may be used 

 conveniently for the 

 solution and the seed 

 emersed in any con- 

 venient container which 

 will permit the escape 

 of the water back into 

 the barrel. It is not 

 necessary that the seed 

 be rinsed in clean water 



PiGXJRE 6. — Dipping sweet po- 

 tato seed in mercuric-chloride 

 1:8 for eight minutes just before 

 bedding. 



before bedding. After treating three or four lots of 

 seed, the solution should be discarded or more corrosive 

 sublimate added. This treatment is designed to kill the 

 disease spores on the surface rather than to reach those 

 that may be present within a partly decayed tuber. 

 Although having no effect on stem-rot, this treatment 

 is helpful in controlling black-rot and soft-rot, if the 

 tubers are not already affected. It has also been re- 

 ported that soft-rot may be prevented by dipping the 

 seed in equal parts of sulfur and air-slaked lime.^ 



1 Report of the conference on sweet potato problems and on 

 diseases of cotton, corn and tomatoes, Birmingham, Ala., Feb., 

 1919. 



