220 COItN CROPS 



Army worms. — Where army worms migrate, the 

 remedy generally recommended is to establish a post- 

 hole barrier by plowing several furrows toward the colony ; 

 in the bottom of the last furrow, dig post holes into which 

 the army worms fall and are killed with kerosene. 



DISEASES OF CORN 



150. The diseases affecting corn are the common corn 

 smut ( Ustilago zea}, and certain ear rots, the most serious 

 of which is caused by a fungus known botanically as 

 Diplodia zeat. Other forms of ear rot are caused by species 

 of Fusarium. Both these diseases live over on infected 

 stalks and ears, producing spores abundantly the follow- 

 ing spring and summer to infect the new crop. The only 

 remedy is to gather up and destroy by fire the infected 

 material. 



Corn is remarkably free from injurious diseases. It is 

 rarely that the loss from smut or ear rot in a field will 

 amount to so much as 1 per cent. Occasionally serious 

 loss occurs. 



References on insects injurious to corn : — 

 111. Agr. Exp. Sta., Bui. 44. Insect Injuries to the Seed and 



Root of Indian Corn. 1896. 

 111. Agr. Exp. Sta., Bui. 79. The Corn Bill-bugs in Illinois. 



1902. 

 lU. Agr. Exp. Sta., Bnl. 95. The More Important Insect 



Injuries to Indian Corn. 1904. 

 lU. Agr. Exp. Sta., Bui. 104. Field Experiments and Ob- 

 servation on Insects Injurious to Indian Corn. 1905. 

 111. Agr. Exp. Sta., Bui. 130. Experiments with Repellents 



against the Corn Root-aphis. 1905 and 1906. 

 111. Agr. Exp. Sta., Bui. 131. Habits and Behavior of the 



Cornfield Ant. 1908. 

 U. S. Dept. Agr., Farmers' Bui. 259. Corn BiU-bugs and Root 



Louse. 



