246 Practical Farming 



The spraying should begin as soon as the tops of the 

 potatoes are a few inches high and should be repeated 

 every second week. As the beetles appear add to the 

 fifty gallons of the Bordeaux mixture one-fourth of a 

 pound of Paris green or a pound of arsenate of soda, the 

 latter the better. It is well to use this as soon as the mature 

 beetles are seen, for while they do not eat much, they do 

 eat, and the more of these that are killed the fewer eggs 

 will be laid and the fewer of the ravenous larvae we will 

 have to destroy. 



For the prevention of the scab, which spoils the appear- 

 ance of the tubers, we should always have the acid effect 

 of the tumed-under and fermenting sod. We should 

 avoid land on which potatoes have grown scabby, and if 

 we are obliged to plant scabby potatoes we should treat 

 them before planting with a fungicide. For this purpose 

 the best is to make a solution of formaldehyde, commonly 

 sold under the commercial name of FormaHn. One 

 pound or pint of this in thirty gallons of water will answer. 

 Put the potatoes in a sack and suspend them in a cask 

 containing the solution and let them soak for an hour, 

 and then spread out and dry them. The solution is good 

 so long as enough remains, but it is better to add to it a 

 freshly-made solution of the same strength. The same 

 solution can be profitably used for soaking seed wheat 

 and oats to prevent the smut and rust. 



