THE SORGHUMS 245 



brush not passing through the machine, but being held 

 against the revolving cylinders. 



Drying is done rapidly in the shade of special sheds and 

 away from strong light, so as to retain the green color. In 

 a shed for curing broom-corn, the layers of threshed brush 

 are only 2 or 3 inches thick on flat supports, so as to insure 

 ample ventilation and quick curing. 



After curing, the brush is packed into bales weighing 

 from 300 to 400 pounds. 



228. Enemies. — The principal insect enemies are plant- 

 lice and chinch-bugs. Sorghum smut is the most serious 

 fungous disease. This is carried through the seed and can 

 be prevented by soaking the seed for fifteen minutes in 

 water kept at a temperature of 135° F. 



LABORATORY EXERCISES 



(1) Write a description of each class and variety of sorghum 

 of which specimens can be obtained, noting especially the follow- 

 ing: — 



(a) Color of naked seed ; 

 (6) Color and size of chaff ; 



(c) Whether seed is almost completely covered by chaff, 

 or projects slightly, or is largely uncovered. 



(2) Write a description of the heads of each class and variety of 

 sorghum of which specimens can be obtained, noting especially 

 the following : — 



(a) Compactness of head ; 



(6) Shape of head, — oval, cylindrical, roundish, fan- 

 shaped, or irregular, — illustrating the shape by 

 drawing the outlines of each head ; 



(c) Length of head in inches. 



