SUDAN GRASS AND RELATED PLANTS. 63 



California, and the selections will have to be tried in the Gulf coast 

 region before their disease resistance can be determined. 



Another opportunity for success in breeding operations lies in the 

 production of a grain-bearing strain of grass sorghum, as discussed 

 under the section " Sudan grass as a grain crop." The difficulties 

 in the way of producing such a strain of Sudan grass seem to be less 

 than those connected with the production of a disease-resistant 

 strain. It is an easy matter by crossing with the Freed sorghum, 

 feterita, or kafir to obtain intermediate forms with nearly pure-white 

 seeds. These hybrids yield much more seed than Sudan grass, but 

 none have been found as yet which will compete with the grain 

 sorghums. The present results, however, make it seem worth while 

 to continue work along this line. 



DISEASES OF SUDAN GRASS. 



The most destructive disease of Sudan grass is the red-spot, or 

 sorghum blight, a bacterial disease which in its effect on the plant 

 resembles the rust on small grains. Red-spot is present wherever 

 Sudan grass is grown, but is a limiting factor in the production of 

 Sudan grass only in the warm, humid regions along the South 

 Atlantic and Gulf coasts. 



The kernel smut of sorghums, Sphacelotheca sorghi (Link) Clinton, 

 also attacks Sudan grass, but this can be controlled by treating the 

 seed with formaldehyde. 6 



Besides the two rather important diseases named above, Taubenhaus 

 (21, p. 22) declares that a rust caused by the organism Puccinia 

 purpurea Cooke was prevalent in Texas during the season of 1919 

 and lists the anthracnose caused by Colletotrichum cereale Manns as 

 present on Sudan grass. The causal fungus of the anthracnose is 

 carried over in the seed and in the stubble or straw. Rotation of crops 

 and treatment of the seed with formaldehyde, as suggested for grain 

 smut, are the most effective methods of control. Taubenhaus states 

 that little is yet known about methods for controlling rust, but that 

 it is destructive only in wet seasons. 



INSECT ENEMIES OF SUDAN GRASS. 



The same insects which interfere with the culture of sorghum also 

 attack Sudan grass. Grasshoppers are fond of it and do considerable 

 damage in localities where they are abundant. The most effective 

 method of controlling their depredations is by scattering poisoned 

 bran mash about the edges of the Sudan grass fields. Chinch bugs 

 are troublesome at intervals when the seasonal conditions are favor- 

 able for their multiplication in other crops. The sorghum midge 



6 For methods of seed treatment with formaldehyde, see Farmers' Bulletin 939, entitled "Cereal Smuts 

 and the Disinfection of Seed Grain." 



