80 DISEASES OF TROPICAL PLANTS CH. 



moist chamber, the fungus will develop readily and be 

 easily recognized. There is considerable difference 

 of opinion as to the fungus that causes this disease, but 

 after looking over the literature carefully the writer has 



decided to refer it to 

 Colletotrichum falca- 

 tum, Went, although 

 not sure that this is 

 correct. Massee and 

 certain other writers 

 believe that the disease 

 is due to Tricho- 

 sphaeria sacchari, 

 Massee, which is also 

 supposed to be the 

 cause of the "rind" 

 disease in the West 

 Indies (see page 81). 

 Other writers insist 

 that the real cause is 

 C. falcatum, and that 

 the T. sacchari, Massee, 

 follows as a secondary 

 fungus. 



The diseased canes 

 are frequently found 

 to be injured by insects, 

 especially borers, and 

 \ no doubt these wounds 



It fc J \ facilitate the entrance 



of the fungus, which 

 in turn does much more 

 damage than the in- 

 sects themselves. 

 Some writers insist that this fungus is more strictly 

 saprophytic than parasitic, and that it cannot attack 

 healthy canes. Others say that it cannot attack 

 mature canes except through wounds, but that it can 

 attack young plants. However, the young canes are 



FIG. 37. Sugar-cane affected with red rot. 

 (Photo by C. W. Edgerton.) 



