132 



THE PARA RUBBER TREE 



The trees which were tapped continuously throughout 

 1911 maintained as healthy an appearance as those not 

 tapped ; they continued to give a good yield of rubber 

 and the renewal of the bark was satisfactory. In 

 Groups II., III. and IV. the average yield of rubber per 

 tree from 152 tappings was 2 lb. 19 oz. AU the original 

 bark of the trees of Group II., which were tapped for 

 the first time in 1908, was used up during 1911, and the 

 average yield of rubber per tree was 5 lb. 1| oz. from 

 320 tappings during the four years. The renewed bark 

 is now being tapped, and the results indicate a better 

 return than from the original bark. 



A series of tapping experiments was conducted at 

 Tarquah during November 1909 on a number of Para 

 trees planted in June 1904. Fifteen trees of 25 in. 

 average girth were tapped by means of three half-spirals 

 connected by a vertical channel ; the tapping was done 

 twelve times on alternate days, and yielded 2 lb. 8 oz. 

 of dry biscuit rubber. Fifteen other trees of 25*8 in. 

 average girth were tapped by means of three large V's 

 connected by a vertical channel ; the tapping was done 

 twelve times as before, on alternate days, and yielded 

 2 lb. 10 oz. of dry biscuit rubber. The yield of rubber 

 from the two experiments was 5 lb. 2 oz. of dry biscuit 

 and 12 oz. of scrap, giving a total of 5 lb. 14 oz., an 

 average of 313 oz. per tree for twelve tappings, extending 

 over twenty-three days, or 026 oz. per tree per tapping. 



The same thirty trees were again tapped every alter- 

 nate day, except Sundays, from March to December 1910, 

 and gave the following results : 



During 1911 thirty trees at Tarquah, having an 

 average girtli of 32^ in., were tapped on alternate days 

 throughout the year. TJie total yield of dry rubber 



