HOW TO FIGHT POTATO ENEMIES. 

 Chas. D. Woods. 



Because of the importance of the subject and numerous 

 inquiries from correspondents, the following specific directions 

 for combatting the more common insect and fungus enemies of 

 the potato have been prepared. The directions are based not 

 only upon our experiments, experience and observation, but upon 

 those of other investigators and practical growers in this and 

 other states. 



By far the larger part of the enemies of the potato may readily 

 be held in check by spraying with the more common insecticides 

 and fungicides, and often, by a combination of materials, several 

 enemies may be met with one application. The insect enemies 

 can be met after they appear. The fungus diseases can be pre- 

 vented and the successful fight must be made before they appear. 

 In some seasons there is comparatively little loss from the attack 

 of fungus diseases. In others the crop is a failure unless preven- 

 tive measures are taken. No man can tell before hand whether 

 the season will be favorable to the growth of the fungi or not. 

 The moral is evident. Preventive measures must be taken with 

 each crop. 



INSECT ENEMIES. 



The flea beetle, which eats small round holes in the leaves, and 

 the Colorado beetle ("potato bug"), which prefers the leaves, 

 eats the stems and will eat the tuber if nothing else offers, readily 

 succumb to poison. Their very greediness makes them the 

 easier victims. 



No adequate substitute for arsenical poisons has yet been 

 found. Some things, are distasteful and if abundantly applied 

 will drive the beetles. Paris green is the most generally used. 

 Lead Arsenate proved the most satisfactory with us.* To kill 

 all the bugs the poison must be distributed over the entire plant. 

 This is most readily and surely done by spraying. See formulas 

 3, 3a, 4 and 4a. 



*For results of experiments with insecticides on potatoes see Bulletin 68 of this 

 Station. 



