460 



Experiment V. 



A most interesting experiment confirming the necessity of ail 

 interval of rest of six months, and the advantage of morning over 

 evening tappings as while the former represent the second period 

 of tapping and the yield of latex less, the ratio of caoutchouc was 

 greater, and it may be noticed that the morning tappings included 

 80 trees tapped by single i icisions. The average yield per tree 

 per annum including scrap was 1 lb. 13 ozs. 



Experiment VI. 



According to the synopsis of this experiment daily tappings 

 shew a better result than alternate days. The poor return during 

 November, December, 1905, and January, 1900, or first period of 

 tapping within a year may be partly explained bv recalling 

 that the heaviest fruit crop recorded terminated in December, the 

 heavy fruit crop and tapping period being conterminous. The 

 whole group of trees therefore, was uniformly dormant. Despite 

 this fall-off the trees average 3! lbs. gross. 



Summary. 



The great problem involved in the scientific cultivation of rubber 

 trees is briefly how to obtain the largest amount of rubber at the 

 cost of the least injury to the tree, and the least damage to the 

 bark. This result depends mainly on three points, viz : — 



(a) the use of the most suitable tapping knife or other imple- 

 ment for making the incisions 



(J?) the selection of the best season or seasons, and time for 

 tapping 



(c) and the system which allows of the most rapid wound 

 recovery. 



Tapping Implements. 



The kind of instrument used has a direct bearing on the actual 

 flow of latex. From observations of the effects of incisions made 

 by various implements, we are convinced that the tree responds 

 to shock and the implement capable of making the cleanest and 

 quickest incision is the ideal one. 



This we have found in an English pattern obtainable in Singa- 

 pore, it is a modified farrier's blade adjusted by a screw in a sliding 

 socket and can be fixed at different angles as desired. It is 

 substantial and makes a grooved incision, thus forming an excellent 

 channel and saving drip, and is equally good for all methods of 

 tapping. 



Nearly all other invented knives or tools have been experimented 

 with at the Botanic Gardens, some have been found unhandy, others 

 unsuited for coolie use, and some much too fragile. 



