104 maine agricuetural, experiment station. i914. 



Corrosive Subeimate. 



Corrosive sublimate 4 ounces 



Water 30 gallons 



Soak tubers i 1-2 hours in this solution. 



Planters and other tools which have in any way come in con- 

 tact with the germs of powdery scab should be washed clean 

 with water and then thoroughly washed or sprayed with a 

 strong solution of formaldehyde and allowed to stand a few 

 days before using. Barrels or other containers may be han- 

 dled in the same way. Sacks can be disinfected by soaking m 

 formaldehyde but the same results could doubtless be obtained 

 at less expense by steam sterilization at some central station. 

 Sacks should be purchased only under a guarantee that they are 

 free from contamination with powdery scab. 



Special attention should be given to storage houses. Ail 

 loose dirt and rubbish, including decayed poattoes or other culk, 

 should be removed from the interior and from around the out- 

 side of the house. As much of this material as possible should 

 be burned. What remains unburned should be thoroughly 

 soaked with a strong solution of copper sulphate. After all 

 rubbish has been removed from the potato house the interior 

 walls and floors should be thoroughly sprayed with a solution of 

 copper sulphate 5 pounds to 50 gallons of water. 



More complete disinfection of empty houses may be secured 

 by the use of formaldehyde gas following spraying with copper 

 sulphate. To accomplish this make all outside doors and win- 

 dows as tight as possible. For every 1000 cubic feet of contents 

 use 23 ounces of potassium permanganate and 3 pints of for- 

 maldehyde. Spread the permanganate evenly over the bottom 

 of one or more large vessels like a wash tub or half of a kero- 

 sene barrel, these latter arranged in the central parts of the 

 house or rooms. Pour the formaldehyde quickly over the 

 permanganate, being sure that it is well mixed with the latter. 

 Leave and tightly close the house at once. Allow to remam 

 closed 24 hours or longer. Barrels and tools, if clean, can be 

 disinfected at the same time, although probably not so thor- 

 oughly and efficiently as by washing with formaldehyde solu- 

 tion. 



