138 PRACTICAL CORN CULTURE 



States from this disease must sometimes amount to at least 

 $25,000,000 in one year. 



Remedy: Since the spores live through the winter on the 

 old corn stalks some authorities urge the farmer to burn 

 the old stalks. It is our opinion, however, that the stalks 

 turned under will be a greater benefit to the land than the 

 injury due to the ear rot will be to the crop. Since the ear 

 rot does not attack any other crop than corn it is better to 

 put the field in some other crop and the corn on new ground 

 if the field was badly affected with the disease the year before. 



Smut: Besides ear rot, smut is the only other disease 

 which injures corn to any extent. Smut in appearance is 

 greenish white or black and is usually noticed on the green 

 stalk or leaf. Smut grows very rapidly and sometimes forms 

 balls four inches in diameter. These balls are composed of 

 millions of plants which are individually too small to be seen 

 with the naked eye. While infection may be brought about 

 directly by the spore alighting on the corn plant it is chiefly 

 due to the conidia which are the result of the spore germi- 

 nating in manure or heavily manured soil. While corn smut 

 is abundant all over the United States, it seems that the 

 injury in any one field is never great. Every year we see 

 more or less smut in our own fields, but we have never 

 known a field to be injured as much as one per cent. 



It is claimed by many farmers that smut is injurious to 

 cattle and horses and that it is the cause of the corn-stalk 

 disease. In order to prove or disprove this opinion the 

 Bureau of Animal Industry has carried on a number of 

 experiments in feeding smut to cattle and horses. The results 

 of these experiments show that there are no injurious effects 

 produced by feeding smut. The best way to kill smut is to 

 cut out and burn the diseased stalks, but this will not pre- 

 vent its reappearance unless it is practiced over a large 

 territory. 



