142 THE RUBBER INDUSTRY 



opened daily. Various experiments have been under- 

 taken at Peradeniya and on private estates with the 

 object of deciding this very important point, but the 

 evidence brought forward hitherto is not conclusive in 

 regard to the general average results over large areas. 

 The tendency of the trials made in different districts is 

 to demonstrate that results are very largely dependent on 

 local conditions of rainfall, soil, and atmospheric in- 

 fluences, and the state of health of the trees. It may 

 be possible to adjust conditions to some extent by the 

 application of various classes of manure. Some tests in 

 this direction have been made recently, but these have 

 not yet been carried out to a sufficient extent to permit 

 of the formation of any definite opinion on the subject. 

 It is of the utmost importance that this question should 

 be solved, for fewer tappings mean economy in labour 

 and a substantial reduction in the cost of production of 

 every pound of rubber, and also additional time for the 

 recovery of the latex cells and the general health of the 

 tree. 



The renewal of the cortex over the tapped surface is 

 fairly satisfactory in Ceylon, although not nearly so 

 rapid as the growth in the Malay Peninsula or in the 

 Amazon Valley. At the higher altitudes the renewal is 

 slower than in the districts of the Kelani Valley and 

 Kalutara. In order to counteract any unsatisfactory 

 results in connection with the somewhat slow growth, 

 the experiment is being made of tapping with one cut 

 only in place of two or three excisions ; on one estate in 

 Matale where this test has been made the average yield 

 of latex per acre showed no diminution at the end of 

 a trial extending over six months. If further experience 



