i6o Report of the Botanist of the 



cents per acre. When the poison is applied with a sprayer the dif- 

 ference is merely the cost of the copper sulphate and a little extra 

 labor in preparing the bordeaux. 



Our recommendation to use paris green with bordeaux at the rate 

 of one-half to three-fourth of a pound to 50 gallons of bordeaux has 

 been criticised by some farmers who say the quantity of poison is too 

 small. They cannot kill the " bugs." At the Station we have had 

 no difficulty in controlling " bugs " with the amount of paris green 

 named, but our success is due to two things : 



(i) The application of bordeaux and poison has been made 

 promptly upon the appearance of the " bugs." This is important, 

 bacause a young " bug " is much more easily poisoned than the full 

 grown beetle. The younger the " bugs " the more easily they are 

 poisoned. 



(2) At the Station spraying is usually done very thoroughly, using 

 100 gallons or more per acre ; while farmers mostly use 25 to 50 gal- 

 lons per acre. In using 100 gallons per acre the paris green would be 

 applied at the rate of one pound per acre; while farmers using the 

 same formula, and applying 25 gallons per acre would make a pound 

 of paris green cover four acres. That is the difificulty. The important 

 point to decide is not how much poison to use with 50 gallons of 

 bordeaux, but, rather, how much poison to apply per acre. Accord- 

 ingly, the directions for the use of poison have been changed (See 

 page 161), 



In this connection it may be mentioned that we think very highly 

 of white arsenic as a poison for " bugs " provided it is used with 

 Ixjrdeaux. Its chief advantage is its cheapness. A pound of white 

 arsenic is equal to about two pounds of paris green in poisoning prop- 

 erties and costs only about one-third as much. Hence, it is about 

 one-sixth as expensive as paris green. 



It is prepared for use as follows; — Dissolve one pound of white 

 arsenic and four pounds of salsoda (washing soda) in one gallon of 



