V PRID 1, 1903.] 
THE TROPICAL 
AGRICULTURIST. 
653 
The figures are:— 
ozs. of dry rubber 
1st experiment eight tappings on 20 trees gave 73i 
2nd 59i 
3rd „ 116 
As this is the result of a single experiment it is impos- 
sible to conclude what was the real cause of the in- 
creased yield obtained whilst the trees were resting. It 
possibly might have been due to the difference in the 
atmospherical conditions or more probably, I think, to 
the inclusion of one or two trees which for some unknown 
reason had given a much better return than their 
neighbours, It may be remarked in passing that the 
results, so far as they go are directly opposed to the 
theory recently promulgated, as to the effect of tension 
on the flow of latex ; or even if it be accepted that 
the thickening of the hast tissue was nearing comple- 
tion, and that the tension was therefore approxima- 
ting the maximum, what is there to account for the 
decided decrease, only a fortnight later, at a time 
when the sap was rising in the stem ? 
The cause of the increased or decreased flow, how- 
ever, does not effect the producer to any great extent 
and seeing that most of the experiments 
previously referred to were conducted during the 
months of June, July and August, when the trees 
were bearing a heavy crop of seed, it would appear 
that tapping operations might be prosecuted with 
advantage during all stages of the plant's existence. 
It is to be hoped that further experiments will bear 
this out, otherwise, if tapping is to be restricted to 
certain seasons, the question of labour will prove a 
serioiTS problem. 
A dry season nevertheless has advantages over a 
wet one, ia-aa-mnch as the work is greatly facilitated 
but the flow of latex is affected to a slight extent, 
owing to the fact that it dries more quickly on the 
wound, I have found that by simply removing the 
coagulated rubber from the wound an hour after the 
incision had been made that a further flow of latex 
occurred. Though only a very small flow it shews 
that probably a greater yield would have been ob- 
tained previously had not the coagulation of the latex 
on the wound prevented a further exudation. The 
variations in yield from day to day, of the same tree, 
noticeable in all the foregoing Tables, are no doubt 
due to some extent to the prevailing climatical condi- 
tions, it having been noticed on many ocoasionsi that 
a larger yield was obtained on a dull, still day. 
It is of the utmost importance to get the tapping 
finished as early in the morning as possible, and with 
this object in view all preparations should be made 
the previous evening, so that a commencement can be 
made at daylight. On estates vrhere the cultivation 
is divided between rubber and other products, j 
wonid advise that no tapping should take place later 
than 9 a, m., but where rubber is the sole cultivation, 
such a course would probably be found impracticable. 
The nmiher of times a tree can he tapped and the length 
of time v;hich should elapse hefore tapping can be 
repeated, depends, I consider, not so much upon the 
amount of latex extracted at the first tapping as it 
does upon the injury inflicted upon the tree during the 
extraction of that latex. It has been seen in the ex- 
periments dealing with the area of trunk to be tapped 
that an equal amount of latex was obtained imme- 
diately after the first tapping by continuing the opera- 
tions on the opposite side of the trunk, and although 
by this means over 5 pounds of dry rubber has been 
taken from a single nine year old tree, the supply was 
by no means exhausted, but the injury inflicted must 
be considered as severe and cannot therefore be re- 
commended. Moreover it is probable that an equal 
amount of rubber might have been obtained had the 
labour expended on this one tree been divided between 
say four trees, in which caso the wounds at the 
finish would be reduced by three-fourths and conse- 
quently would heal up much quicker, 
I would lay down as a general rule to follow, that 
having regard to the welfare of the tree, it is advi- 
sable to postpone farther tapping antil the old wouudj 
are completely healed up, This remark applies mort 
especially to young growing trees, in which cage there 
would be a considerablo risk of arresting the grov/ch of 
the tree, if it be tapped first on cue side aud then on the 
other, before the original wounds are completely 
healed up. 
I have found that nine year old trees on which the 
incisions had been renewed on nine or ten occasions 
had completely recovered, i.e., the wound was quite 
covered over with nsvv tissue, on the occasion of my 
next visit, exactly twelve months afterwards, and were 
therefore ready for further tupping. On the other 
hand, those wounds which had been renewed 14 or 15 
times were far from hjiug healed up and in soma cases 
there was still IJ to 2 inches of wood exposed evea 
after a lap^e of 12 months. Although these trees 
were again tapped aud in most oases a yield eqaal to 
that of the previous year was obtained, it was I con- 
sider a risky proceeding. Par better work through 
the whole estate, selecting the best trees and tapping 
them lightly— renewing the incisions eight or nine 
times, by which time the trees operated upon first 
will probably have completely recovered and will be 
ready for further tapping. 
Age at lohich tapping can proMahlij commence.— "Ez- 
perimeuts for the purpose of ascertaining the age at 
which tapping can profitably commence are necessarily 
very incomplete as there are hardly any trees avail- 
able between the ages of four and nine years. 
Recently some three-and-a-half and four year old 
trees growing on one of the lari,'est rubber estates in 
Selangor, have being tapped, but the results clearly 
indicate that this is too ycuug, I append the re;ult of 
tappmg 50, three-and-a-half year old trees. These 
were planted 14' X 14' (222 to the acrej, the average 
girth of all the originally planted trees being 17-51 
inches at 3 feet from the ground, and that of the 50 
trees selected 21-24 inches. The tapning was on the 
herring-bone principle and the incisions, which were 
confined to the first 2 feet of the trunk, were renewed 
on 12 alternate days. 
Table XVII, 
Result of tapping 3^ year old trees. 
t3 
g 
oo 
(3 i-i 
SI 
1 a 
O !-l 
ft. 
in 
ft. 
in. 
1 
1 
10 
2'5 
87 
1 
7 
1- 
3 
1 
7 
1. 
88 
CI 
0 
2-25 
6 
1 
7 
3- 
94 
1 
9 
1-25 
10 
1 
8 
Nil. 
97 
1 
10 
•75 
18 
1 
9 
■5 
102 
1 
9 
•75 
25 
1 
8 
1- 
103 
1 
8 
•5 
23 
1 
7 
2- 
103 
1 
8 
!• 
30 
2 
0 
1-25 
106 
1 
9 
•75 
31 
1 
11 
2- 25 
107 
1 
10 
35 
34 
1 
10 
1.75 
112 
1 
8 
•75 
38 
2 
1 
'5 
114 
1 
8 
125 
44 
2 
2 
I'o 
123 
1 
10 
1'25 
47 
1 
7 
1-75 
125 
1 
7 
1-25 
53 
1 
10 
1-25 
130 
1 
10 
1- 
59 
1 
9 
1-25 
131 
1 
8 
1, 
65 
1 
9 
1-5 
134 
1 
9 
•75 
66 
1 
10 
1- 
137 
1 
10 
1-25 
68 
1 
9 
1- 
189 
1 
10 
1-25 
69 
1 
8 
■5 
141 
1 
9 
•75 
70 
1 
10 
1 5 
142 
1 
7 
•5 
71 
1 
8 
1- 
144 
1 
9 
1' 
75 
1 
7 
1-5 
150 
a 
1 
1-25 
76 
1 
9 
1-25 
152 
1 
9 
2"25 
78 
1 
9 
■75 
153 
1 
10 
1- 
27 
1 
10 
1-5 
161 
1 
8 
1-75 
