178 Diseases of Truck Crops 



it is not wise to bed them untreated. In using prime 

 seed they might easily soft rot in the bed. This 

 rotting may be increased where the ends are clipped. 

 To obviate this possibility and to destroy the spores 

 of disease, the seed should be disinfected with a solu- 

 tion of corrosive sublimate made up of one ounce of 

 the chemical dissolved in eight gallons of water, and 

 the seed soaked for ten minutes. Usually it is 

 advisable to treat one bushel at a time. For large 

 quantities of seed, 100 to 200 gallons of the solution 

 may be prepared in several fifty gallon barrels. 



Besides treating the seed, the soil in the seed bed 

 must be disinfected. This may be done with the 

 steam method, see pages 54-56, or with the for- 

 maldehyde method, page 53. 



Where flue, hot water, or manure heated beds are 

 used permanently, the wooden framework should be 

 disinfected every year by thoroughly sprinkling or 

 soaking with corrosive sublimate solution or the 

 formaldehyde solution of the same strength as used 

 for the seed. As soon as the framework begins to 

 rot, it should be discarded. 



FIELD METHODS OF CONTROL 



The grower's efforts to stamp out the diseases of 

 the sweet potato cannot stop with care that the seed 

 shall be healthy and the seed bed clean. It has al- 

 ready been shown that several diseases like black 

 rot, stem wilt, ground rot or pit, and soilstain may be 

 and are carried over in the soil. These diseases con- 



