18 ANARCHY OF AGRICULTURE 



blanket, or may alternately thaw and freeze till the wheat is killed. 

 Late spring frosts may injure winter wheat or decrease acreage of 

 spring wheat. Early frosts in the fall injure the wheat, as happened 

 in 1907 and 1911 in the Northwest and in the Canadian West. 

 Rain at harvest time, extreme heat, prolonged drouth, all may do 

 serious damage to the wheat crop. In 1902 the Australian crop 

 fell from 42,500,000 bushels of the previous year to 19,800,000 

 bushels. The 1903 crop rose to seventy-five million. This drouth 

 had the effect of raising the price of wheat in the Pacific Coast 

 States above the Liverpool price level. Bad weather conditions 

 also lead to rust and smut which injure the crop seriously. Hail 

 is an agent of destruction. Floods, as in Kansas in 1904, may 

 destroy large areas of wheat. This same year, 1904, was known 

 in America as Black Rust year, since the total loss due to this 

 cause was seventy-five million bushels. 



What has been said about climatic conditions and the wheat 

 crop is believed to be typical for other farm crops. And these 

 conditions can neither be foreseen nor removed. 



Insects and Diseases. Among the insect pests may be men- 

 tioned the " green bug" (Toxoptera graminum). The green bug 

 made its appearance in 1890 and proved very disastrous to wheat 

 and oats over a section of the country extending from Texas to 

 Northern Missouri and eastward to Indiana. Again in 1900, and 

 still again in 1907, this green bug appeared. In 1907 it attacked 

 the wheat crop and almost totally destroyed the Texas crop, and 

 seriously damaged the crops of Oklahoma and Kansas. The 

 wheat grower also is in constant danger of serious loss from the 

 Hessian fly, the chinch bug, the wheat midge, and the weevil. 

 Other crops have an equal number of enemies. 



Bulletins from our Agricultural Experiment Stations show the 

 great variety and serious extent of plant and animal diseases in 

 the United States. For livestock, as well as field crops, are in 

 constant peril of disease. For instance, one bulletin of the Wis- 

 consin Station alone treats of the following pathological conditions 

 and insect enemies in that State : vaccine treatment of chicken-pox 

 in fowls; contagious abortion (described as "the greatest menace 

 to our dairy cattle"); root killing and body canker (in orchards 

 and small fruits); potato rot and blight; potato scab; five cabbage 

 diseases (black rot, soft rot, yellows, black leg, club root); rust 

 and leaf blight of field crops; barley stripe disease; alfalfa leaf spot; 

 cottony maple scale; cutworms; onion maggots (destroying from 

 fifty to ninety-five per cent of the crop); codling moth (apple 



