DISEASES OF SUGAR CANE 



291 



root disease is Marasmhis Sacchari Wakker, which is very 

 common in cane fields generally, its mycelium developing freely 

 in the thrown-out parts of cane-stools after cutting, on dead 

 shoots, and on adhering trash ; it can be shown to occur in old 

 roots. The extent to which it appears above soil level is largely 

 determined by the amount of moisture locally present. The 

 mycelium is recognisable by the way in which, by developing a 

 gelatinous consistency, it sticks the leaf sheaths together, appear- 

 ing when they are separated like a layer of dried flour paste. 

 It is further distinguishable from that of the fungus next to be 

 described by the absence of either feathery structure or of a 

 uniform granular layer formed on the external leaf sheaths of 

 the infested stools. 



Fig. 115 



Odontia sacchari, Cystidium and Basidium with Single Spore 



From Bull. Porto Rico, Ins. Expt. Sta. 



The fructifications of Marasmius are small white papery 

 toadstools, usually less than half an inch across. They may be 

 formed in abundance on infested material, but only under very 

 moist conditions, generally after heavy rain. They quickly dry 

 up and disappear on a sunny day. Their connection with the 

 white mycelium described has been established by cultures, and 

 they develop on infested material, including dead roots, kept in 

 a moist chamber. 



There are other species of Marasmius occurring on sugar-cane, 

 seen especially in Trinidad, but to some extent in Barbados 

 Their mode of occurrence appears to be essentially the same as 

 that of M. Sacchari. 



