cane was growdng poorlj', and where the stalks with dead tops were 

 very numerous. The dead tops showed at the heart a soft Avhite 

 putrid mass indicating a bacterial rot. liorei's were present in the 

 stalks but not in the tops. 



Top-rot has been reported in Java but no definite conclusions were 

 reached as to its cause, nor was it clearly diagnosed as a specifie 

 disease. 



DISEASES OF THE LEAF. 



THE RED SPOT OP THE LEAP-SHEATH {Cercospora Vaginae). 



The red spot of the leaf-sheath is an extremely common disease 

 of many varieties of cane, so much so in fact that the reddening of 

 the lower leaf-sheaths becomes almost a distinguishing character of 

 some types. Infection occurs on the upper sheaths while they are 

 still green and closely appressed to the stalk. The areas are at 

 first quite regular in shape, bright red in color, and sharply set off 

 from the normal green tissues surrounding. They increase in size 

 rapidly, becoming irregular in shape, and finally cover the larger 

 portion of the sheath. The fungus not only spreads over a given 

 leaf-sheath but invades those beneath, the area attacked on each 

 successively becoming smaller and smaller as it passes toward the 

 center. However, several to many points of infection may be set 

 up on each sheath. This action is sufficient to insure the spread of 

 the disease to all the leaves of any one stalk. The leaf blades have 

 not been found subject to attack. Occasional lesions ascribed to 

 this fungus are found on the stalks. Fruiting areas occur as black 

 patches often several inches in diameter at the center of the infected 

 regions of the outer sheaths. 



This disease has been reported from the West Indies by Banci*oft 

 (5, 6), from Java by Wakker (92), and by Kruger and Went (53). 

 and from Reunion by Colson in his work on the sugar industry of 

 that island. 



As is the case with so many leaf diseases it is somewhat dititiciilt 

 to make any definite statements as to the amount of damage caused. 

 It ordinarily passes without notice, and is in fact considered a natural 

 phase of the growth of the cane by most planters, but it is certain 

 that it is responsible for some decrease in sugai' content because of 

 its action in l>ringing about a ])remature death of the leaves. 



Such experiments as have been carried out during two seasons 

 Avere contradictory. In the experiment of 1911, cuttings of Oris 

 talina cari'j were used, all badly diseased. One hundred of these were 



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