AGRICULTURAL BULLETIN 



OF THE 



STRAITS 



AND 



FEDERATED MALAY STATES. 



No. 8.] AUGUST, 1905. [Vol. IV. 



RESULTS OP THE EXPERIMENTAL TAPPINGS 

 OP HEVEA BRASILIENSIS 



At the Economic Gardens at Tjikeumeuh 

 made during i9oo-i904 



By Dr. W. R. TROMP De HAAS. 



By permission of the author, we publish a translation from the 

 Dutch of the experiments on Para Rubber conducted in the Econo- 

 mic Gardens in Java. The paper was published in Teysmannia, 

 Part 10 (1905), p. 182. The system of coagulating with alcohol is 

 interesting though not practicable commercially on account of ex- 

 pense. It will be noticed too that stress is laid on the dryness from 

 sun and wind interfering with tapping. The importance of sufficient 

 humidity in the estate, especially in the ground, is becoming more 

 and more evident and this will have a great bearing on the selection 

 of sites for plantations. There is little doubt that the latex is 

 formed in the roots and that a larger proportion of latex can be 

 extracted when the tree is turgescent from a liberal supply of water 

 absorbed by the roots. Hence it would seem of the greatest impor- 

 tance that the roots should be able to obtain a sufficient supply of 

 water for the tree, which might not be the case in very dry 

 ground. 



We shall here once more shortly review the results which we have 

 obtained to this day, concerning the tapping of Hevea Brasiliensis. 

 They have gradually led us to the methods of tapping which are 

 now used by us. 



In the first year, the experiments made on the Hevea trees grow- 

 ing in the Economic Gardens shewed us that the yield of the latex 

 of Hevea Brasiliensis attains its highest point after the tap- 

 wounds have been re-opened several times in succession at intervals, 



