426 



THE FARMERS HANDBOOK. 



The destruction of the smut boil or smut gall by cutting it out and 

 burning it is the method to be adopted in coping with this pest, as it 

 deprives the spores of the opportunity to infect other plants or other 

 parts of the same plant. Moisture is necessary for infection, and hence 

 damp weather is most favourable to the spread of the disease. Stevens 

 and Hall state that the only practical way of dealing with this smut is to 

 go through the maize-field at regular short intervals and cut out, collect, 

 and destroy the galls before they have a chance to liberate their spores. It 

 is unwise to feed the diseased plants to stock, as many of the spores pass 

 through the animal uninjured, and are able to develop to a certain degree 

 in the manure, which may thus become a fresh centre of infection. 



Head Smut of Maize (Sorosporium reiliamim, Kiihn, McAlp.). 



Until comparatively recently this was the only smut of maize known in 

 Australia. In districts where maize is largely grown the disease is spread- 

 ing. It attacks the cobs and tassels, and is usually confined to them, but, in 

 exceptional cases, a few patches of smut may appear on the upper leaves 

 and leaf sheaths. The smut is enclosed at first in a pinkish membrane, 



Showing the effect ot Smut infestation. 



which soon ruptures in order to allow the escape of the spores. It is dis- 

 tinguished from American Corn Smut by not enlarging the ears and 

 forming large smut boils, by generally confining itself to the inflorescence, 

 and not attacking the leaves and stems. 



The spores of the fungus are very abundant and drop from the smutted 

 heads to the soil where infection of young germinating maize seedlings 

 subsequently occurs. The life-history is still incompletely known. While 

 to a certain extent the disease is spread mechanically on seed maize — the 



