37 



CLEAN CLEARING, PESTS AND DISEASES. 



By W. E. Shbltok-Agae, 

 (Manager, Kamuning Estate, Perah, F.M.8.) 



If I were asked to classify the various diseases and pests 

 according to their relative activity in i-egard to rubber plant life, 

 I should put disease into two classes — 



(1) " Those that are fatal " ; 



(2) " Those that are amenable to treatment " ; 



and pests into both, viz. : 



Fatal class (I). 

 All root diseases — such as 

 Fames, Hymenochiete, Ustulina 

 and Poria. 



Amenable class (II). 

 Stem and bark diseases — such 

 as pink disease, Diplodia, thread 

 blight and cankex-s. 



Pests — Temies gestroi and boi"ers. 



I do not include vermin, as most wild animals, so far as rubber 

 is concerned, could be classed as such and measures to deal with 

 them, as a rule, are easily attended to. 



As it will be impossible in a paper of this kind to deal 

 individually with them all, I shall merely offer, for discussion 

 categorically, four salient points : 



Prevention ; 

 Treatment ; 



Incidence and 

 Control. 



Prevektion of Disease. 



Sa long as there is " no cure " for any fatal disease, obviously 

 the next best thing is prevention. 



Now prevention in this case means eliminating causability, or, in 

 other words, having reference to all the fatal diseases and pests 

 of class one. 



The argument in favour of " clean clearing " is not mere theory, 

 it has a practical side as well. Take those rubber estates that have 

 been developed out of old tobacco, tapioca and lalang lands, they 

 rarely give evidence of any appreciable trouble, and though we 

 have these practical illustrations, timber clearing has never yet 

 gained the whole-hearted support it merits. In some cases it is 

 undoubtedly a matter of £ 8. d., but in others it is not so. Some 

 planters hold that " by cleai'ing timber much valuable humus matter 

 is lost," and also that " no immunity exists from pests and disease so 

 long as the roots and stumps of trees are allowed to remain in the 

 gi'ound." 



These are admittedly weighty views, and the argumenta are 

 correct up to a point. 



