DISEASES OF SUGAR CANE 



309 



Causative Fungus. 



The disease is due to a very inconspicuous fungus, Cephalo- 

 sporium Sacchari, Bull., of which the slender colourless hyphae 

 penetrate all the tissues of the stem. In the hollow which 

 forms in the centre of diseased canes the fungus collects in a 

 white fluffy mass and there the hyphae bear on short, mostly 

 simple branches, terminal heads of one-celled conidia, variable 

 in size and shape. The fungus can live as a saprophyte on a 

 variety of materials and probably occurs in the soil. 



Symptoms. 



As seen externally the effects of the disease in India are 



Fig. 125 Cephalosporium Sacchari 

 From Memoirs, Dept. Agri., India 



reported to be very much the same as those of red-rot, namely 

 the drying-up of the leaves, and, finally, of the stems. In the 

 Barbados outbreak it was observed that canes might be attacked 

 rather severely in the lower internodes without the tops being 

 very noticeably affected. As mentioned above, however, the 

 disease in this case seemed to be rather suddenly checked. In 

 Nevis more notable damage was reported. 



The discoloration seen on splitting the cane differs froni that 

 typical of red-rot, being a more uniform and duller red, tending to 

 muddiness, and without the contrasted white patches seen in 

 red-rot. In the earlier stages the discoloration tends to run 

 in vertical lines. A brown patch on the outside marks where 

 the fungus has killed the underlying tissue. This in the Barbados 

 examples extended from the nodes, and the internal discoloration 



