TAPPING 169 



trees, fall very heavily on the first and second year's working. 

 Then there is also the fact to be borne in mind that, in some 

 cases, the trees give very poor yields at the beginning. When 

 trees are only yielding 2 to 2j grammes of rubber the manager 

 is sometimes blamed for high tapping-costs. If the trees were 

 yielding six grammes he would be praised for having managed 

 well, as the costs of tapping would amount to only about half 

 as much on the yield. 



In the Preanger district in Mid- Java, for example, trees 

 give exceedingly poor returns on the first year's tapping, say 

 about 2j grammes, and tapping-costs are necessarily high. In 

 the second year, however, the trees give excellent yields of 

 about 6 grammes, and the tapping-costs fall to a low level. 

 The merit or demerit, as the case may be, in such instances 

 attaches to the trees, not to the manager. In Sumatra, on the 

 other hand, trees generally yield exceedingly well from the 

 commencement of tapping, and the same may be said to apply 

 to the Federated Malay States, on well-kept estates. 



A very foolish course to pursue, when trees have been too 

 closely planted and bark is not renewing well, is to lop off a 

 number of the lower branches of the trees so as to let in more light 

 and air. In the circumstances described above the trees have 

 too few branches and much too little foliage. Such a course 

 as this one would think is self-condemned. Yet it is not un- 

 commonly advised by some visiting-agents when they find 

 that bark is renewing badly. 



In his most interesting and valuable book, The Physiology 

 and Diseases of Hevea Brasiliensis, Mr T. Petch makes some 

 remarks on this subject. He says: 



" The advice has been given that, in order to secure a good 

 renewal of cortex, the sun should be allowed to have access to 

 the stems, and that for this purpose the trees should be lopped 

 if necessary. While there may conceivably be instances in 

 which lopping, and consequent exposure of the stem to full 

 sunlight, might be advisable, as, for example, in severe attacks 

 of canker, it can certainly be said that, as a general practice, 

 it would defeat the object desired. Renewal of the cortex 

 is favoured by a damp atmosphere ; it is said to be more rapid 

 in the Federated Malay States than in Ceylon, probably because 



