178 T BIN ID AD AND TOBAGO BULLETIN. \XVIIL 4, 



PLANT DISEASES AND PESTS. 



A ROOT DISEASE OF CACAO IN TRINIDAD. 



ROSELLINIA PEPO. 



By W. NowELL, D.I.C. with an introductory note by 

 W. G. Freeman, B.Sc. 



The death of Cacao trees from "root disease" has been known in 

 the Colony for a long time, but does not appear to have been specially 

 investigated. The cause of death has often been assigned vaguely to 

 "canker at the root." 



The root diseases of cacao and limes in some of the West Indian 

 Islands have been the subject of research by Mr. W. Nowell, D.I.C, 

 Mycologist on the Staff of the Imperial Department of Agriculture for 

 the West Indies. His results are published in a paper " Rosellinia Root 

 Diseases in the Lesser Antilles" V/est Indian Bulletin XVI. 1917 31-71 

 with twelve illustrations. 



During Mr. Nowell's visit in 1918 to investigate the Froghopper 

 blight of Sugar cane, he expressed to me his belief that although 

 Rosellinia had not been recorded as a cause of root disease of cacao etc., 

 in Trinidad and Tobago, it would be found here, considering its wide 

 distribution in the West Indies and tropical America. Root disease of 

 cacao is not very common in the Colony, and as Mr. Nowell had very little 

 time available he had few opportunities for searching for it. A few 

 trees were examined but without definite result. 



During his second visit in 1919 Mr. Nowell and I visited an estate 

 where trees in a particular area had died, special attention being directed 

 to it by the hibiscus hedge dying out along the length of the same bed 

 in which the deaths of cacao trees had occurred. 



