258 



The Supplement to the Tropical Agriculturist 



A research is being carried out by Mr Bate- 

 son, Assistant Mycologist, on the depletion of 

 the food reserves of Para rubber trees by tap- 

 ping and other natural demands on the vitality 

 of the trees. 



The quality of tapping, by which I mean the 

 number of cuts to the inchand the proper depth 

 of the cuts, is a subject on which planters as a 

 whole are keenly interested. Twenty cuts to 

 the inch is a very good average, although a good 

 many more than this are claimed by some es- 

 tates. The cuts should, of course, be sufficiently 

 deep to tap all the latex, and yet must avoid 

 injuring the cambium, which lies immediately 

 beneath. When it is considered that a good 

 cooly will do over 1,000 cuts per day, besides 

 the incidental work of bringing in his latex, 

 washing cups, pails, etc., it is evident that it 

 requires very skilled labour to avoid all mistakes. 



Lack of Supervision, 



When bad tapping ie met with it is usually 

 traceable to one of two causes. Either the labour 

 force is new or is always changing, resulting in 

 unskilled tappers being employed, or else 

 there is insufficient supervision of the coolies. 



When wounds are made in tapping they 

 should be treated, as suggested in my report 

 for 1910, by painting them over with coal tar. 

 This is done on some estates as a routine mea- 

 sure, with excellent results. The tar must, of 

 course, be of the right consistency, sufficiently 

 fluid to be painted on (a stalk of rubber leaf 

 makes a good brufh) but no fluid allowed to run 

 down the bark. The tapper should be made to 

 paint all the wounds on his own trees ; he does 

 not like it, as it draws attention to his mistakes, 

 but, when persevered in, the system is of great 

 advantage from this point of view alone, besides 

 achieving its primary object, which is to assist 

 in getting a clean growth of new bark over the 

 wound. 



Manufaotube. 

 Crepe and smoked sheet still balance one 

 another as the favourite forms in which planta- 

 fion rubber is exported. Towards the end of 

 the year there was practically no difference bet- 

 ween the prices obtained for these two forms of 

 rubber. I still rotain my preference for smoked 

 sheet over crepe, though, undoubtedly, muoh of 

 the fine crepe, produced in the Federated Malay 

 States is excellent rubber. A great deal of extra 

 work on estates has been caused by the demand 

 in the market for a very light coloured crepe. 

 This is, I think, quite an unnecessary refine- 

 ment; and the exact shade of colour of fine 

 crepe has really very little bearing on its quality. 

 When this is realized a good many Managers 

 will be saved a large amount of time and trouble 

 involved in grading their rubber to a dozen or 

 more different shades of colour, the whole of 

 which are of one perfectly uniform quality. 



Driers. 



A point that should be considered by many 

 estates is the ad visibility of installing arrange- 

 ments for more rapid drying of their rubber, 

 particularly where thickish crepe is manufac- 

 tured, and where large quantities have to be 

 handled. There are some special hot air driers 



on the market which appear to work success- 

 fully. But even a simple arrangement of fans 

 to keep the air in motion, combined with, pos- 

 sibly, a heating or drying arrangement f >r the 

 incoming current, should be easily installed and 

 should reduce the time taken in drying im- 

 mensely. This would result in a smaller space 

 being required for stores, less money tied upio 

 the form of wet rubber, and generally cleaner 

 rubber. With a view to testing the actual com- 

 mercial value of raw rubbers produced in the 

 country, the purchase of an experimental vul- 

 canizing plant has been approved for 1912. 

 Tests. 



Apart from the special research on methods of 

 coagulation and curing, a large number of 

 rubber samples have been received from various 

 estates, showing certain defects, with requests 

 from Estate Managers for advice. 



The principal defects found in such samples 

 were: (1) air bubbles, caused by using too con- 

 centrated solutions of coagulant and improper 

 mixing; (2) "Spot" diseases due to the fungi 

 or bacteria, which have been investigated by the 

 Assistant Mycologist/- Mr. Bancroft ; (3) tacki- 

 ness, due to exposure to the heat of the sun or 

 other heat ; (5) discolorations, due, usually, to 

 oil on the rollers from the bearings. 



A small experimental smoke-house of the 

 Kent "hop drying" type has been erected 

 during the year and proved very useful, — Pinang 

 Gazette. 



PESTS AND DISEASES OF RUBBER 

 IN THE F.M.S. 



Report for 1911. 

 In his report for 1911 the Director of Agricul- 

 ture, F. M. S., makes the following interesting 

 remarks : — 



Insect Pests. 

 Among the pests of rubber, white ants 

 (Termes gestroi) continue to require attention 

 but they are, undoubtedly, on the decrease. It 

 would be interesting to have figures on this 

 point. At a rough estimate the Entomologist 

 estimates that over similar areas the number of 

 trees attacked by these insects, now, as com- 

 pared with the number of 1907, would be 60 per 

 cent. less. This reduction is due to two reasons : 

 firstly, planters have now a systematic method 

 of dealing with these insects; sec< ndly, because 

 T. gestroi cannot maintain the same rate of in- 

 crease on older estates where felled wood has 

 rotted, f he systematic campaign against these 

 insects on all young estates prevents it increasing 

 in such numbers, as it did in former years, when 

 there was no systematic treatment. A few 

 planters complain that after treating young trees 

 with the fumes of arsenic and sulphur or red- 

 hot charcoal the trees di«. This may be due to 

 the presence of root fungus, for there is, no 

 doubt, that in a large number of cases Fomes 

 semitoxtus is the original cause of the trouble 

 when white auts are present. There is uo reason 

 why the fumes should produce a harmful effect 

 upon the tree. Too great a heat may be 

 harmful. Our own experiments have been en- 

 tirely successful. 



