136 RUBBER AND 



on closely planted estates. How far it can be adopted 

 as a permanent system of tapping can only be deter- 

 mined by further trial. 



Excision Methods of Tapping. 



At the present time the method which is almost 

 universally adopted on estates is paring on some system 

 or other. The results are generally so satisfactory that 

 paring is not likely to be given up in favour of any 

 method of pricking, until very clear proof of the 

 superiority of the latter is forthcoming. 



The precise system of paring will partly depend 

 upon the period which is to be allowed for bark re- 

 newal. At the present time it is generally recommended 

 that the renewed bark should not be touched until a 

 period of four years has elapsed from the beginning 

 of tapping. There is some reason for believing that 

 even this interval, which is longer than that formerly 

 adopted on many estates, may be profitably increased. 

 It is probable also that a longer period is required for 

 each successive renewal. 



As regards the size of tree upon which paring may 

 safely be begun, it is generally considered that trees 

 less than five years old from planting should not be 

 tapped at any point where they are less than 18 

 inches in girth. The reason for this restriction is that 

 where the circumference is smaller, the bark is so thin 

 that it is almost impossible to pare without causing 



