DISEASES AND PESTS 57 



been possible to determine, by bacteria alone ; the other 

 by bacteria following an initial attack by a fungus, 

 which Fredholm calls Diplodia. If one may judge at 

 a distance, from the descriptions of the symptoms, he 

 will conclude that both forms occur throughout the 

 American tropics, and that the complicated form is 

 decidedly the commoner and more dangerous. 



Stockdale's report, already quoted for other diseases, 

 takes up also bud rot, and under this head deals almost 

 entirely with the purely bacterial form. Quoting from 

 him : 



The youngest leaves appear to stand upright and do not 

 unfold as they should. Afterward they turn yellow and then 

 brown in colour, and the whole appearance is that of a withering 

 tree with the centre of the cabbage in an unhealthy condition. 

 . . . After a time the terminal bud falls over, frequently leaving 

 a ring of quite healthy -looking leaves at the top of a " headless " 

 trunk. . . . This rot, in a diseased palm that is still standing, 

 is invisible until the harder outer coverings of the bud are 

 removed and it is found to be limited to the softer tissues. . . . 

 A badly diseased bud is generally full of fly larvae, etc., and 

 the smell is awful. . . . Microscopic examination of the roots 

 and stem indicated that they were quite normal, while those 

 portions of the terminal bud, in the advancing margin of the 

 disease, showed in most cases bacteria of different kinds. 



The few isolated cases in the Cedros district would indicate 

 that this disease is not of a very infectious character, but large 

 numbers have been killed out in the Siparia district, the spread 

 being very rapid and apparently from the windward. ... It 

 would appear i to be largely due to unfavourable conditions of 

 soil, drainage, etc. . . . With our present knowledge of the 

 nature of the disease, it is impossible to suggest a remedy for 

 trees that are already infected, and therefore steps must be 

 taken for preventing its spread. It is suggested that the top 

 four or five feet should be cut from the diseased trees and 

 buried deeply with lime. 



Fredholm also found a few cases of bud rot in which 

 no Diplodia could be found with the microscope, and 

 in which the characteristic symptoms of the latter were 

 absent. When the bud rot is purely bacterial, then, 

 the first symptoms are shown by the youngest leaves. 



