165 



REPORT ON DISEASE IN SUGAR CANE. 



Director of Public Gardens 8fc. to the Honourable Colonial Secretary. 



28th May, 1895. 



Sir, 



I visited last February three sugar estates on which I was informed 

 there was some disease in canes. 



2. On one estate, Savoy and Danks, in Clarendon, the moth borer 

 only could be detected. This insect pest has been fully described and 

 discussed by Prof. Cockerell in the Bulletin of this Department for 

 April, 1892*. It was by no means serious, and can probably be kept 

 under without much difficulty. 



3. It was noticed also that tops brought from a distant estate for 

 planting were infected with the same borer. Although it is an excel- 

 lent practice to plant tops brought from other districts and thus en- 

 courage vigour in the canes, yet care should be taken in seeing that such 

 tops are not infected with any disease. In the article in the Bulletin, 

 the recommendation made for dealing with tops is to immerse them 

 in water at a temperature of 130° F. for 48 hours, to which may be 

 added, as an additional precaution, a one per cent, solution of car- 

 bolic acid. 



4. The other two estates, Cave Valley and Greenock in St. Ann's, 

 are a considerable distance from the first but adjoining one another. I 

 took specimens of diseased canes with me to Kew last June, and the 

 fungus was determined to be the root-fungus (Colletotrichum falcatum.) 



5. Mr. Massee suspected this fungus to be only a form of the rind- 

 fungus (Trichosphceria sacchari) but at that time I had not seen the 

 rind-fungus on these estates. His conjecture has proved to be correct, for 

 experiments at Kew have shown that the root-fungus is only another 

 form of the rind-fungus. 



6. Some canes on Greenock were affected, but not many. On Cave 

 Valley, however, a very great deal of damage has been done by the root 

 disease ; for instance, on one piece of nine acres, the canes which were 

 " first ratoons" had only given 6 hogsheads, and then died out. On 

 several pieces the plant canes had not ratooned, though some had 

 sprung to the height of about two feet 6 inches, and then died. On 

 another piece which had already been cut, the canes that Trere lying 

 with the trash were badly diseased with the rind-fungus and also with 

 the shot -borer. Generally speaking the root-fungus seemed to be more 

 deadly than the rind-fungus, and the latter was seen only in mature 

 ripe canes. 



7. The root-fungus showed clearly where it was doing its deadly work 

 by the stunted, short-jointed appearance of the cane, and the yellowish 

 look of the leaves. When the plants were dug up, the roots were in 

 some cases all dead, and the plant was living on the small store of nour- 

 ishment already existing in the short cane, and pushing out new shoots 

 which only hastened the inevitable end. In other plants the roots 

 were still living but the other portions were decayed. 



