362 



The Supplement to the Tropical Agriculturist 



at an elevation of over 2,000 feet in wet 

 zones or below 600 feet in very dry zones; 

 but beside these areas, unless tapping 

 methods are much improved, very much 

 larger areas may become unproductive in the 

 near future. It is to be presumed that every- 

 one interested in the cultivation of rubber will 

 by now have read Prof. Dr. Hans Fitting's ex- 

 cellent treatise on " The physiological principles 

 for determining the value of the various Rubber 

 Tapping Methods." Anyone who has read it 

 and grasped the full meaning of the various ex- 

 periments therein described must admit that 

 a very grave risk is being run where half 

 the tree is tapped out one year and the other 

 half gone on to directly after ; and far more so 

 where both sides are tapped at once, or one 

 side one month and the other side next month, 

 these operations practically girdling the tree. 

 I believe most up-to-date authorities (any- 

 how in the Straits) accept the principle that 

 there must be a sufficiently wide vertical down 

 strip of untouched bark, or of bark sufficiently 

 renewed (say, of not less than 3 years old), to 

 enable it to perform its necessary functions 

 in the proper nutrition of the tree— the idea of 

 tapping a quarter-section only of the lower 5 to 

 6 feet of the tree at one time being accepted as 

 probably the safest system to adopt. However, 

 to get a quarter-section sufficiently large to be 

 worth tapping, it is necessary to leave the tree 

 untapped until it is from 6 to 8 years old. 



To get over this difficulty and be able to 

 start tapping any tree that is 16 in. in girth at 

 3 feet from the ground, I have evolved what 

 I claim to be an original system. The origi- 

 nality consists in " making allowance for 

 the annual increment in girth of the rubber 

 tree." Cultivated, clean weeded, and manured, 

 a good four to five year old rubber tree will 

 put on from 5" to 6' in girth in twelve months. 

 My system, therefore, is to mark out on the half 

 spiral, or full herring-bone, system, at an angle 

 of about 60°, two cuts only, on the lower side of 

 one-half only, of any tree that is 16" in girth 

 at 3 feet from the ground, the bottom cut being 

 15" from the ground, and the second cut 12 in. 

 above this. Tap these out in ] 2 months and 

 then, instead of as is now almost universally 

 done, going round and tapping the ocher side of 

 the tree, put on 3 more cuts at 12 in. apart 

 above these two cuts, and tap them out for 

 another 12 months, incising not more than 

 one inch of bark per mensem. When these 

 three cuts are finished, it will be two years 

 since the first marking, and the tree, which 

 then was 16 in. to 18 in. at three feet from 

 the ground, should be 28 in. to 30 in. at that 

 heignt. Leave alone the side tapped out, which 

 I would call (a a 1) and divide the untapped 

 side of the tree into two-thirds and tap 2/3rds 

 of this area, which I call (b. b 1) on the same 

 lines, leaving untouched the l/3rd section 

 which I call (c. c 1). It will now take another 

 two years to tap out the bark on (b. b 1), and by 

 then the tree will further have increased in 

 girth, so that section (c. c 1) will be quite wide 

 enough to tap.— When tapping is commenced on 

 (c. c 1) the bark on (a. a 1) will be 4 years and 

 3 years old, and sufficiently renewed to perform 

 the necessary functions for the proper nutri- 



tion of the tree. — When (c. c 1) are tapped 

 out, the cycle of tapping can again be com- 

 menced on (a. a 1), the bark on (b. b 1) by 

 then being 4 years and 3 years old. 



There will thus always be a wide vertical 

 down strip of bark not less than 3 years old, 

 connecting the crown to the base of the tree, 

 capable of carrying out the necessary downward 

 sap-transport, which is essential if the health 

 and vigour of the tree is to be fully maintained. 



J. SHERIDAN- PATTERSON. 



THE INVERTED V SYSTEM AND ITS 

 SCIENTIFIC MERITS. 



We direct special attentiou to the following 

 letter from "Inverted V" which sets forth 

 the advantages — in the light of recente scientific 

 study and experiment— of a tapping system 

 the writer, a practical planter, advocated in our 

 columns so far back as 1907. Certainly it is a 

 feather in his cap that the wisdom of this sys- 

 tem he urged 3£ years ago should be justified 

 by the scientific children of a rather later time. 



Neboda, Sept. 21st. 

 Sir,— Early in 1907, I advocated a system of 

 Tapping called the Inverted V as it appeared 

 to me as a rational method. Its advantages 

 over the existing methods were fully discussed 

 in the columns of the Observer, with the re- 

 sult that planters have since adopted the two 

 boundary channels as a sine qua non in Rubber 

 Tapping. . 



Now Dr. Fitting has published the results of 

 his experiments in Tapping and suggestions for 

 rational tapping methods, and people are eager 

 to find out a system which will answer his sug- 

 gestions. I therefore feel justified in bringing 

 to light the Inverted V System, as it answers 

 all the suggestions of Dr. Fitting for a rational 

 method ; and I give below in parallel columns 

 for the benefit of those interested the practical 

 advantages as published in the Ceylon Observer 

 of the 18th February, 1907, and in Tropical Aqri- 

 cutturisi of March, 1907, and their scientific 

 reasons : — 



Practical Advantages Scientific Reasons and 

 (published on Feb. lath, 07.) Suggestions. 



1 Serves the same purpose (1) Adopt the half herring 

 as the Half herring bone. bone incision as your tapping 



system or better still the full 

 herring boue— the V shaped 

 incision (Dr. Fitting) 



2 Only requires two verti- (2) Vertical channels re- 

 cal instead of 4 or with her- lieve the tension of the tis- 

 ring bone. sues which hinders the flow 



of ,latex ; hence these have 

 been limited to two. 



3 Incisions being shorter (3) Two small incisions 

 than half spiral, latex runs which are situated on the 

 into the channel more easily s;em some distance apart 

 consequently less scrap. yield more latex than a con- 

 tinuous one embracing the 

 same area as the two small 

 ones put together (Dr. Fit- 

 ting) 



4 Prevents the cooly from (4) The special advantage 

 tapping more area on the of boundary channels of the 

 stem of the tree than al- inverted V system has been 

 lotted. adopted in other systems 



after us publication— in fact 

 no rational method could be 

 worked without these. 



