Sugar Beet Webworm 



Paris green gives more satisfactory results and works more quickly 

 than any poison yet used for killing sugar beet webworms. 



In using this poison apply not less than 4 pounds per acre. 

 (For the method of determining the amount of poison applied per acre, 

 see "Test Your Sprayer" on page 35). 



A good type of traction sprayer, when properly adjusted, should 

 apply about 50 gallons of water to the acre. If too little water is used 

 the beet plants are apt to be burned ; if too much is used much poison 

 is wasted. 



Arsenate of lead acts very much more slowly than Paris green, 

 therefore seldom gives satisfactory results. This poison can be secured 

 in two forms, dry and as a paste containing 50% water. These are not 

 recommended except in case Paris green cannot be secured. When 

 used, not less 

 than 8 pounds 

 of the dry or 16 

 pounds of the 

 paste should be 

 applied per acre. 

 If the worms are 

 large, arsenate of 

 lead is not recom- 

 mended, as it acts 

 too slowly. 



Best results are 

 only secured 

 when the poison 

 is applied with a 

 pressure sprayer 

 which will main- 

 tain a pressure of 

 80 pounds. Such 

 a machine pro- 

 duces the fine 

 mist-like spray 

 which is necessary 

 in order to place 

 the poison on the 

 under side of the 

 leaves. 



The effect of spraying at the proper time, with the proper equipment 

 and with the proper amount of Paris green, is clearly shown in Figure 

 12, Page 73. The left of the cut shows the unsprayed portion of the 

 field and the right the sprayed portion. 



See caution regarding the handling of Paris green, given on 

 page 37. 



WHY GROWERS DO NOT SPRAY 



Beet growers have innumerable excuses for not spraying, few of 

 which will stand the test. 



73 



Fig. 12. 



Result of Spraying — Left, Unsprayed; 

 Right, Sprayed 



