1 86 RUBBER AND 



replanting with Hevea in less than twelve months from 

 the date of destroying the diseased trees. This method 

 of isolating an infected area by trenching was first pro- 

 posed by Hartig for use in forestry work. It was 

 recommended by Massee for dealing with Rosellinia in 

 tea. 



Hymenochaete noxia. 



The fructification of Hymenochaete noxia commonly 

 known as Brown Root Disease is much less conspicuous 

 than that of Femes, and is also comparatively rare. 

 When present it takes the form of a thin brown crust 

 adhering to the base of the trunk. The surface of the 

 crust is velvety, being covered with almost microscopical 

 bristles. The disease is not confined to Hevea, but is 

 also found on Castilloa, tea, cacao, camphor, coca and 

 the shade tree Erythrina lithosperma (dadap) in Ceylon ; 

 on Funtumia on the Gold Coast and on coffee in Java. 

 The majority of cases affecting Hevea in Ceylon have 

 occurred where old cacao has been cleared in order 

 to plant rubber. Unlike Fomes, the fungus does not 

 appear to travel independently through the soil, but is 

 -only transmitted where the roots are in contact with 

 other diseased roots or with dead wood upon which the 

 fungus is growing. In order to prevent the appearance 

 of the disease, the stumps of cacao which have been cut 

 down in order to make way for rubber should be care- 

 fully extracted. Hevea trees killed by the fungus should 

 be cut down and the roots dug up and burnt. The soil 



