CEHEALS 329 



changed into smut, the central stalk of the head alone 

 escaping. Adjacent leaves are also occasionally smutted. 



The smut masses, when they first appear, are covered by a 

 white or gray membrane which soon ruptures, loosing the 

 powdery olive-brown mass of spores, which soon blow 

 away. This character enables one to distinguish this with 

 ease from the covered smut. Smutted plants head early, 

 the smut reaching its maximum at flowering time, though 

 scattered heads of smut may appear at other dates. The 

 smutted heads stand high on especially tall stalks, which 

 affords excellent wind distribution of the spores to the 

 surrounding blossoms. The fungus reaching the blossoms 

 gains such foothold upon the developing grain that its use 

 as seed, without treatment, insures a smutted seedhng as 

 offspring. In the plant developing from such an infected 

 seedhng the disease does not show externally until the 

 ripening of the smut at the next blossoming season. 



The fife history of this smut is thus similar to that of 

 wheat loose smut, and the same treatment, i.e., rouging, 

 combined with a modified Jensen hot-water treatment, 

 is effective, preventing all the smut. See p. 372. 



Covered smut (Ustilago Hordei (Pers.) Kell. & Sw.). 

 — In the covered smut, the smut masses occupying the 

 place of the grains and glumes are at first covered by a 

 membrane composed of the outer surface of the glumes 

 of the spikelet. This membrane retains the spores for 

 some time after harvest. The spores, as seen en masse, 

 after the rupture of this cover are very dark to purplish 

 black, with no tint of olive. 



The treatment given for oat smut applies here. 



Ergot. See rye. 



