DISEASES OF CEREALS AND GRASSES 47 



The spores are fairly large and round, with a 

 reticulated surface (see Fig. 9, C and D). 



According to Kiihn the germ tube from both the 

 primary and the secondary conidia is able to enter 

 the host plant, grow within its tissues, and, at the 

 time of grain formation, produce bunted ears. 



A B C 



Fig. 12. — Grains of wheat: (A) shows the shape of the healthy grain; 

 (B) shape of a bunted grain ; note how much broader it is than the 

 healthy one ; (C) longitudinal section of a bunted grain showing the 

 black mass of bunt spores enclosed. 



Some of the differences between smut and bunt 

 are enumerated below : — 



Smut. 



Spores distributed before 



harvest. 

 Spores small, coats 



smooth. 

 Spores odourless. 



oerminate 



c5 



in 

 nutritive 



Spores 



water and 

 media. 



Germinating spores pro- 

 duce a four-celled pro- 



BUNT. 



Grain still intact at har- 

 vest. 



Spores large with reti- 

 culated coats. 



Spores strong hshy 

 odour. 



Spores germinate in 

 water but not in nutri- 

 tive media. 



Pro-mycelium shorter, 

 conidia longer and in 



