730 
THE TROPICAL AGRICULTURIST, 
[April i, 1891. 
of manurial matter and its return to the soil. The 
difBoulty is to retain manorial matter in an active 
condition and yet inodorous, and in this respect 
the Native Guano Company seem to have been 
Buccessful. 
♦ ^ 
CULTIVATION OF INDIARUBBEE. 
In Nature of January 15, in a note on p. 355, 
a statement is quoted, to the effect that some few 
attempts have been made to cultivate iiidiarubber, 
but as yet not very suocessfully. A^, however, there 
are extensive flourishing plantations of Ficus elastica 
in Assam, a short account of their origin and present 
condition may prove interesting. 
After some preliminary experiments on a small 
scale, the Government of Assam in 1873 determined 
to plant caoutchouc in the Charduar Forest at the 
foot of the Himala3as, north of Tezpur. Mr. Gustav 
Mann, the Conservator of Forests, gave me the 
necessary instructions to start the work in November 
of that year, and I remained in charge of the plan- 
tation till September 1875. Tho Charduar Forest has 
an essentially damp climate, the average rainfall at 
the caoutchouc plantation having been 94'65 inches 
during the years 1878—85, and during 1880 — 89, the 
annual rainfall was distributed as fiillows : — 
Winter Rainfall. 1880-87. 1887-88 1888-89 
November till March. ..Inches 4'87 7'38 4'78 
Summer Rainfall 1886- 1887, 1888. 
April till October... „ 99-30 71'55 82-39 
Total ... „ 104-17 78-93 87-17 
Data for the temperature of the Charduar Forest 
are not available, but the following average figures 
for ten years, for Sibsagar, which lies to the south- 
east of Tezpur, across the Brahmaputra River, will 
give sufficiently approximate results : — 
Average annual temperature 73°-4 F. 
Average monthly for J rnuary (lowest)... 69° 0 F. 
Average monthly for July (highest) ... 83°'7 F. 
The absolute maximum and minimum temperatures 
for Sibsagar are not given in the meteorological tables 
from which the above figures are taken, but quoting 
from memory, they are for Tezpur about 95° and 42° 
respectively. 
The relative humidity for Sibsagar averages 83 per 
cent., being lowest in March, 79 per cent., and highest 
in January, September, and December, at 85 per cent. 
It is certainly not less than this in tho Oharduar 
Forest, where the moist hot atmosphere in the 
summer months resembles that of a forcing house. 
The Charduar Forest contains a vast number of woody 
species, both evergreen and deciduous, but chiefly 
the former, nearly pure woods of Mesua ferrea and 
Altingia exceha prevail in the higher parts of the 
fores-, and the undergrowth consists of dwarf palms, 
small bamboos, and evergreen shrubs, (Jaffea bengalensis 
being abundant in places, whilst cane palms are found 
in the damper parts of theforesia, and festoon the 
trees in company with other huge climbers. A few 
enormous o'd rubber-trees are disseminated here and 
there throughout the forest. Ficus dcisiica has here 
been measured 129 feet high, with a girth around 
the principal aerial roots of 138 feet, whilst the girth 
of its crown was Gil fiot. 
A- rubber-tr. os cannot stand shade, and the seedlings 
damp off unless fully exposed to light and well drained, 
the natural reproductmn of Ficus elastica generally 
takes place in the forks of stag-headed or lightly 
foliaged trees high up in the ciown, where seeds are 
left by birds; and from such a site the aerial roots 
in process of timo de.scend to the gx-ouud, and 
develop into a vast hollow cylinder around ihe foster 
stem, which is speedily inclosed and completely killed 
by the vigorous crown of the eiiiphyte, which even- 
tually rcjilacea it in the forest- In its epiphytic 
growth, the aerial roots of Ficus elastica may tako 
gever-il years to reach the ground, but, once well 
rooted, nothing can probably surpass it in its native 
habitat for rapidity of growth and vigour. 
As, owing to the above mode of growth, rubber trees 
are so sparsely scattered in the Assam forests, and it 
IS thereiore extremely difficult to protect them from 
being tapped in a wasteful manner, the plan of concen- 
mating them in artificial plantations, as proposed to the 
Government by Mr. Mann, was carried out as follows ; 
At first, attempts were made to propagate by cuttings, 
uu readily, but it was soon discovered that 
rubber-seed germinates freely on well-drained beds 
covered with powdered charocal or brick-dust, and 
that the seedlings, though at first small as cress, 
grew rapidly, and became about 2 feet high in 
twelve months, and were much hardier against drought 
thau plants produced from cuttings. Tha base of 
the stem of the eeediings swells out like a carrot, 
and this fact, no doubt, enables them to tide through 
the dry season in safety, for, in spite of the humi- 
dity of the air, the nearly constant sunshine from 
November till March is trying to young plants 
In order to imitate nature as much as possible, 
some strong seedling rubber-plants were placed in 
the forks of trees in 1874, and by 1885 only a few 
of them had reached the ground and were growing 
most vigorously. ^ 
As this method, though ranch more economical 
than planting on the' ground, gave such slow results, 
and it was found easy to produce plants in any quantity 
nom seed, large nurseries were formed, in which the 
plants, are now retained until they are 10 feet high 
as smaller plants were brow.sed down by deer when 
planted out in the forest. The planting lines are 
cleared to a breadth of 40 feet in strips, separated 
by alternating strips of untouched forest 60 feet wide. 
It was found that the rubber-plants did not get 
sufficient light with lines le.ss than 40 feet broad 
whilst the strips of forest kept the soil and at- 
mosphere moist, and afforded side shelter to tha 
plants, forcing them to grow upwards, instead of 
branching out near the ground. As this method in- 
volves considerable expense in clearing the lines and 
wastes the wood, which is frequently unsaleable, 
Oolonel, now General Keatinge, the Ohief Commis- 
sioner of Assam, in 1874, directed that plantations 
Ficus cldsttcci sb.ou.ici £ilso b© loS/do in gTfiss»l£m(i 
near Tezpur. It has been, however, found thaUarge 
rubber-trees in Tezpur, when tapped, yield scarcely 
any rubber, the difference between them and the 
rubber-trees of the Charduar Forest being probably 
due to the greater dampness of tha atmosphere and 
soil m the latter locality, as compared with the 
Brahmaputra Valley. 
An area only of 8 acres was therefore planted out 
near Tezpur, whilst the area of the Charduar plan- 
tation in 1889, was 1,106 acres, and contained 16,054 
plants, besides large nurseries with 84,000 seedlings. 
Local Governments in India, which have to find funds 
for all sorts of administrative purposes, are naturally 
inclined to economize, and Sir Charles Eliot, when 
Chief Commissioner of Assam, about ten years ago 
proposed to stop further work on the Charduar plan- 
tation, but this was vigorously opposed by Dr. Sohlich 
the Inspector-General of Forests, and at his advice* 
the Government of India directed the further exten- 
sion of the plantation. Apparently, however, little 
progress was made between 1881 and 1888, when an 
additional area of 63 acres was planted up. Regard- 
ing the growth of the plants, the following figures 
taken from Mr. Mann’s report on the Assam forest 
administration for 1838-89, give the average height 
and ginh, up to April 1889, of 50 trees in each year’s 
planting ; — 
Average . Growth since last 
Year when 
year. 
planted. 
Height. 
Girth. 
Height. 
Girth. 
1874-75 
ft. lU. 
ft. in. 
ft. in. 
ft. 
in. 
61 11 
11 5 
6 1 
0 
9 
1875-70 
57 6 
7 10 
5 2 
0 
6 
1876-77 
55 10 
7 5 
3 7 
0 
6 
1877-78 
53 9 
5 11 
5 3 
0 
7 
1878-79 
46 2 
4 6 
4 0 0 
6 
1879-80 
44 10 
5 2 
5 9 1 
2 
1880-81 
38 7 
4 2 
6 7 0 
8 
