4 io 



MAIZE 



CHAP. 

 X. 



out on the surface of the invaded parts as a black dusty mass. 



To quote Mr. Pole Evans 

 (i, 2, and 3): " The black 

 powder or smut consists 

 of myriads of microscopic 

 reproductive bodies, com- 

 monly known as spores. 

 They serve to propagate 

 the fungus and dissemin- 

 ate the disease, t and corre- 

 spond in function to seeds 

 in the higher plants. Each 

 spore is brown and spheri- 

 cal, and measures about 

 one thirty -three hun- 

 dredths of an inch in dia- 

 meter. Under favourable 

 conditions these spores 

 germinate, and give rise 

 to a number of secondary 

 bodies, which are blown 

 about by the wind. 



" It is found that the 

 spores germinate more 

 readily, and also give rise to a larger number of secondary 

 bodies, in fresh stable manure than in ordinary soil. Conse- 

 quently, if a heavy dressing of fresh stable manure is applied 

 to land infested with smut spores just before planting, the risk 

 of infection will be much greater to plants growing in such 

 ground, inasmuch as more secondary bodies will be produced 

 than would have occurred in untreated land. 



"As the secondary spores are able to infect all young and 

 tender parts of the maize plant, their presence in the maize 

 lands should be prevented as far as possible. This can best 

 be done by removing and burning all smutted plants, by using 

 seed free from smut spores, and by avoiding the use of fresh 

 stable manure at the time of sowing." 



This parasite is said to occur wherever maize is grown. 

 It appears to be spreading in some parts of South Africa. In 

 some cases in the Standerton District, Transvaal, it was found 



Fig. 157.- 



-Maize smut or brand on the 

 tassel. 



