TAPPING 171 



more dampness in the atmosphere outside the trees, the currents 

 of food and water ascending the sap-wood and descending in 

 the bark are feebler and less ample, and there is a smaller 

 supply of building-up material available for bark-renewal. As 

 will be seen, Mr Petch admits that later on, in any event, the 

 advantage is all with widely-planted trees, and that is un- 

 questionably a sound view. 



The yields from trees vary very much, and the biggest trees 

 are not always the best yielders. Sometimes a tree no bigger 

 than its neighbours will yield twice or three times as much, and 

 sometimes a tree which has been a good yielder will suddenly 

 fall off. When a tree refuses to yield, or yields a very poor and 

 reduced return, it is usually an indication that it is affected 

 by disease and it should at once be very carefully examined. 

 If there is no sign of disease and it is a persistently poor yielder 

 it should be cut out and not allowed to encumber the ground. 

 This should be done before the neighbouring trees cast too heavy 

 a shadow and make successful replanting impossible. If, how- 

 ever, the trees round about are closely planted no replanting 

 should be attempted, as the extra space will benefit the remain- 

 ing trees by giving them more room for root expansion and 

 increased space for their foliage to develop. 



It is advisable that all estates should reserve a few acres 

 of rubber trees untapped, till they arrive at an advanced age, 

 for another and even more important reason. The seeds from 

 untapped trees of advanced age have more vitality than those 

 from trees which have constantly been tapped and too often 

 severely tapped. 



It might also be said that it is an excellent thing for estates 

 to have reasonably large areas of implanted land. These areas 

 may later on become most valuable because, while the shade of 

 old trees makes it impossible to supply vacancies caused by 

 disease and storms of wind, one could look to having additional 

 numbers of young trees planted, say 50 acres, each successive 

 year to make up for any losses sustained. If these young 

 plantings were from the seeds of old untapped trees one might 

 expect the young trees to be of vigorous growth and more likely 

 to withstand the attacks of disease than trees from weaker seeds. 



It would appear to be almost unnecessary to state that the 

 morning is the best time for tapping and that the earlier the 



