USTILAGO 341 



The early removal of the smut-galls before the spores are 

 mature checks the spread of the disease. When the grain is 

 suspected of harbouring spores it should be treated with 

 formalin before sowing. Fresh manure should not be used, 

 as if spores are present in it and produce conidia, the growing 

 plants may be infected. 



Brefeld, Unters. Gesammt. Mykol., 4, p. n. 



Knowles, Jonm. Mycol., 4, 1889. 



Tubeuf and Smith, Diseases of Plants, p. 279. 



Covered smut of barley ( Ustilago hordei, Jensen) attacks 

 the ears of cultivated barley ; the spore-mass, instead of 

 becoming powdery and sooty as usual, remains very hard and 

 persistent, being surrounded by the unbroken wall of the 

 grain, and frequently remains so after harvest. Spores sub- 

 globose, blackish-brown, 6-7 X 5 /*. 



The plant is not infected in the seedling stage, hence it is 

 no use treating the seed. Infection takes place during the 

 following stage, and the grain becomes infected, but shows no 

 sign of injury. Such seed if sown produces a smutted crop. 

 Clean seed, grown in a district free from smut, should be 

 sown. 



Loose smut of barley ( Ustilago nuda, Jensen) also attacks 

 barley; it is distinguished from U. hordei by the spore-masses 

 becoming powdery and sooty, and dispersing as soon, as 

 mature. 



Spores elliptical to globose, soon free and powdery, olive- 

 brown, 5-7 x 5-6 fi. 



Preventive means same as those recommended for covered 

 smut of barley. 



Loose smut of wheat {Ustilago tritici, Jensen) attacks the 

 grain and chaff of wheat, destroying the whole, and forming 

 a loose sooty mass which is dispersed before harvest, as 

 infected plants develop more rapidly than sound ones. 

 Spore mass not foetid. Spores subglobose or elliptical, pale 

 olive, minutely warted, 5'5"7X5-6 \x. Var. foliicola (P. 

 Henn.) grows on the leaves and leaf-sheaths of wheat, and is 

 not uncommon in Egypt ; spores yellowish olive-brown, 4*5-7 

 X4"5-6>- 



In this case the plant is not infected in the seedling stage, 

 hence the treatment of the seed is of no avail. Infection 

 occurs during the flowering stage, and mycelium is formed in 



