1 68 THE RUBBER INDUSTRY 



ally realized the mistakes that had been made, and the 

 necessity of careful and methodical cultivation and 

 treatment to insure successful results.,/ 



After visiting the principal centres of the rubber- 

 planting industry, the conclusion reached can only be 

 that healthy conditions are the rule. The usual 

 diseases exist, but not in an aggravated form ; the most 

 serious obstacles in this direction are : (i) Root canker, 

 or fomes ; this disease produces disastrous results if 

 neglected; but it is understood, and when found is 

 immediately treated by isolating the immediate sur- 

 roundings of the tree, digging up and burning the roots, 

 and applying lime to the infected area. (2) White ants 

 are attacked as soon as they appear. (3) " Die-back " 

 rarely does much damage. (4) Probably the worst pest, 

 and one found in every district of the peninsula to 

 more or less extent, is the formation of burrs or nodules 

 in the bark. While these do not materially affect the 

 general health conditions of the tree, they are a serious 

 interference to tapping. They occur principally on old 

 trees that have been badly tapped in past years, but 

 they are found also on trees that have never been 

 tapped. Dr. Huber of Para considers that they are 

 the result of suppressed bud expansion in conjunction 

 with bad tapping, and this diagnosis is supported by 

 Mr. Lewton Brain, Director of Agriculture in the 

 Federated Malay States. Dr. Huber further thinks 

 they may be induced by the action of hot sunshine on 

 renewed bark causing some form of irritation. In the 

 earlier stages of growth these burrs can be removed 

 without damage to the cambium, but if neglected they 

 spread, and unite with the wood of the tree. Taking a 



