72 AGRICULTURE 



ripe as to shatter, and much loss results. It may be cut 

 while the grain is still soft, so that it can be crushed 

 between the thumb and finger. This will not injure the 

 quality of the grain, and the straw will be of much greater 

 value if cut slightly green. Early cutting also reduces the 

 risk of storms. 



In regions where the grain can be allowed to stand with- 

 out shattering until it has become fully ripe and dry, the 

 cutting and thrashing are often accomplished in one process. 

 This is done by a combination harvester and thrasher drawn 

 by from twenty to thirty horses, or by a tractor engine. 



Wheat cut with the harvester should be carefully 

 shocked, usually in nine-bundle shocks, eight bundles stand- 

 ing firmly on the ground in the form of a circle, and the 

 ninth used for a cap-sheaf. Careless shocking is respon- 

 sible for much loss from weathering. 



When the wheat is well dried in the shock, it should 

 at once be thrashed, or else stacked in well-built stacks. 

 Wheat is too valuable to leave standing long in the field 

 waiting for a thrashing machine. If once put in stacks, 

 it should be allowed to stand for several weeks before 

 thrashing in order that it may "pass through the sweat." 



4. Diseases and Insect Enemies of Wheat 



Wheat is the prey of many different diseases and insect 

 enemies, which sometimes almost totally destroy the crop. 

 Many of these are coming to be better understood, and rem- 

 edies for them devised. Three principal diseases attacking 

 wheat are scab, rust and smut. These are all caused by the 

 growth of fungi on the wheat plant. A fungus is a tiny 

 plant organism that grows upon some other plant, or on 

 animal tissue, and draws its living from its host. We call 



