Minnesota Plant Diseases. 



299 



stroyed and only the loose strings of the woody tissues of the 

 head branches remain. The head smut can be distinguished 

 from the grain-smut by this habit. The smut mass forms a 

 blackish powder. 



No preventives are known for this smut. It is possible that 



the treatment for grain 

 smut will be effective. 



Grain smut of sorghum 

 [Sphacelothcca sorglri (Lk.) 

 C lint o ;]. This sorghum 

 smut attacks the young 

 grains and forms smut 

 masses in them, but does 

 not destroy the glumes. 

 The smutted grains increase 

 in size, chiefly in length, 

 and have a whitish wall 

 which encloses a mass com- 

 posed entirely of spores. 

 The spores rest over winter 

 and under proper condi- 

 tions, in the spring time, 

 form more spores, which 

 can in turn multiply in 

 yeast-like fashion; the re- 

 sulting spores are capable 

 of causing infection. 



Sorghum is also fre- 

 quently attacked by other 

 smuts and certain varieties 

 of the sorghum are known 

 to be peculiarly susceptible 

 to smut. (See also Head 

 Smut of Sorghum.) 



A few experiments on 

 this sinut have indicated 

 that lit it water treatment 



may be beneficial. It ha> proved successful in the treatment of 

 the same smut on broom corn. It is also possible that the for- 

 malin method would be effective and useful. 



' 



14!*.-- C'orn smut < 1'stil.iK" mnydis). on an 

 tar of corn. A few of the kernels near the 

 luitt have not b-.-en smutted. All of the 

 others have been attacked and have in- 

 creased enormously in size. The enl irged 

 kernels are fillid with the smut powder. 

 < Irini'ial. 



