Control Measures 209 



believed that these organisms introduced with the seed 

 affect not only the crop of that year but remain in the 

 soil to attack subsequent crops of the same or other kinds. 



Treating seed tubers is not as troublesome as some 

 farmers think. The treatment, if desired, can be made 

 several weeks in advance of planting, but less handling is 

 necessary if it is made immediately before cutting. Where 

 one has only one hundred bushels or less to be treated, it 

 is convenient to place two or more barrels on a platform, 

 which should be high enough to draw the solution off 

 through a hole near the bottom of the barrel. The pota- 

 toes are dumped into the barrels and are covered with 

 the solution, which may have been prepared in another 

 barrel. One barrel of solution will cover two barrels of 

 potatoes. After they have soaked the required length of 

 time, the solution may be drawn off at the bottom and 

 emptied into the barrel in which it was prepared. The 

 treated tubers can now be emptied on to the ground to be 

 dried, but care should be taken that they are not over- 

 heated by the sun. The barrels can be filled again with 

 potatoes and the same solution used once more. While 

 waiting for this lot to soak the tubers already treated 

 may be cut for planting. This saves time. By using 

 two barrels, it is possible for one man to treat about 50 

 bushels of potatoes in a day and have time to cut tubers 

 for planting between treatments. Two men can treat 

 about 250 bushels in one day by the use of 10 barrels 

 in making the treatment. 



Either formaldehyde or corrosive sublimate may be 

 used. The former is much cheaper, less poisonous and 

 can be used in metal vessels if desired, but it is not as 

 effective in destroying the sclerotia of Rhizoctonia as cor- 

 rosive sublimate. A pint or pound of 40 per cent form- 



