SORGHUMS. 121 



Diseases and Pests. — (1) Kernel Smut {Sphacelotheca 

 sorghi). In Kernel Smut only the individual grains are 

 affected, the head being only slightly changed in appearance. 

 The disease can be controlled by the use of formalin, 



(2) Head Smut {Sphacelotheca reiliana). — Head Smut re- 

 sembles maize smut to some extent ; the entire head is 

 destroyed. On exsertion, the head is found to be composed 

 of a mass of spores covered with a whitish membrane. The 

 ontogeny of the organism is not properly understood, and no 

 satisfactory treatment has been found. Care should be taken 

 to get uninfected seed. 



Eed Spot or Blight (Bacillus sorghi). — Eed spots appear on 

 stems and leaves, causing the latter to die prematurely. Seldom 

 serious ; certain strains are more resistant than others. 



Sorghum Midge (Diplosis sorghicola) .—E^s, laid in flower 

 and ovary destroyed by larvae. No treatment known ; somewhat 

 rare. Early varieties in America are less susceptible to severe 

 injury. 



Eooi Bloom iStriga lutea). — Is parasitic, and should be 

 treated as in maize. 



Sorghum Aphis {Heuning Dow). — This insect has proved 

 serious to late-sown sorghums, especially in the Lowveld. 



REFERENCES: 



1 " Forage Plants and Their Culture."— Piper. 



2 " Botany of Crop Plants." — Robbins. 



3 " The Corn Crops."— Montgomery. 



•» " The Grain Sorghums."— Bulletin No. 102. Okla. 



^ " Better Grain Sorghum Crops."— U.S.D. of Agri. Bulletin 448. 



« " The History and Distribution of Sorghum."— U.S.D. of Agri. Bulletin 



175. 

 " " The Uses of Grain Sorghum."— U.S.D. of Agri. Bulletin 686. 

 « " Kafir."- Bulletin 198, Kansas. 



' " Milo as a Dry-Land Crop."— U.S.D. of Agri. Bulletin 322. 

 » " Kafir as a Grain Crop."— U.S.D. of Agri. Bulletin 552. 

 ' " Saccharine Sorghums for Forage." — U.S.D. of Agri. Bulletin 246. 

 - " The Smuts of Sorghum."— U.S.D. of Agri. Circular Bulletin. 

 ' " Trials with Millets and Sorghums for Grain and Hay in S. Dakota." 



—Bulletin 135, S. Dakota. 

 '• " Broom-Corn Culture." — Texas New Series No. 2. 

 * " Sorghum Crops for Silage." — Circular No. 28, Kansas. 

 8 United States Department of Agriculture No. 634, 1918. 



