DISEASES OF LIME AND OTHER CITRUS TREES 



203 



be necessary that a responsible person who understands the lines of 

 action should direct it. The principles to be followed are set out 

 in Chapter XI. 



As already indicated, when decay has invaded the base of the 

 tree a permanent repair is no longer possible. The life of the 

 remaining parts may, however, be much prolonged in many cases, 

 if it is considered worth while, by cleaning and smoothing off 

 the wood which remains sound, and coating it with a preserva- 

 tive. As the soil moisture hastens decay in this region, it is 

 usually advisable to draw away the earth from the crown, and 

 keep its neighbourhood clear of sheltering weeds. 



Red Root Disease. 



The red root disease of limes, due to an undetermined species 

 of Sphcerostilbe, was first described by F. W. South as occurring 

 on lime estates newly cleared from forest in Dominica. It has 

 been examined by the writer in similar situations, and in an older 

 cultivation situated in a valley subject to flooding by a river 

 carrying abundant forest debris. The disease is not known from 

 other West Indian islands, but material received from a lime 

 estate in British Guiana indicates the presence of a like disease 

 in that country. 



RosELLiNiA Root Disease 

 (See General Diseases). 



Fig. 75 

 Red Root Disease of Lime (Dominica^ 



T. Fetch has given an account of a root disease of a closely 

 similar type on Hevea and arrowroot in Ceylon due to Sphcero- 

 stilbe repens B. et Br., and S. F. Ashby a disease of banana in 



