PARA-RUBBER CULTIVATION 



4i3 



This involves more labour, and has been generally discarded 

 for basal collection. 



The two chief systems of tapping now practised on the 

 estates are those known as the Spiral and the Herring-bone. 

 The principle is the same in both. The initial grooving 

 (tapping) forms a guide for all subsequent tappings performed 

 during the year. 



Spiral System. — A spiral groove is made in the bark of the 

 trunk from a height of six feet to the base. If the incision is 

 carried completely round the stem, then the system is called 

 the Full Spiral ; if only part way round, the Half Spiral. A 

 bole of small girth will only require one spiral. If of larger 

 circumference, then an extra spiral can be added for each 

 additional foot of girth ; thus a tree three feet round would 

 need three. At each tapping a thin shaving of bark is removed 

 from the lower edge of the spiral cut. The pressure of latex 

 is thereby relieved, and a stream flows down the spiral into 

 the receptacle placed at the base. 



The full spiral, of all methods of tapping, yields the largest 

 quantity of rubber in a given time, but is very drastic, as the 

 whole of the cortical tissues from the height of six feet down- 

 wards is removed, most likely too quickly for the maintenance 

 of the tree's general health. It is now considered the best 

 system to adopt for trees which are subsequently to be removed 

 as thinnings or for other reasons. Rubber in quantity is thus 

 obtained with the minimum amount of labour. 



Herring-bone Systems. — A vertical groove is made in the 

 bark of the trunk extending from the base to a height of five or 

 six feet. Then long oblique incisions about a foot apart are 

 cut from it in an upward slanting direction. If the inclined 

 cuts are made alternately on each side of the vertical groove, 

 the method is known as the Full Herring-bone ; if only on one 

 side, the Half Herring-bone, thus : 



Full 

 Herring- 

 bone 



Half 



Herring- 

 bone 



