95 2 
THE TROPICAL 
AGRICULTURIST . 
[May i, 1882. 
The proper time for plucking tea leaf is of importance 
to tea planters, the time, however, when a flush is 
ready to be taken off depends so much on climate 
and cultivaiion, that a hard and fast rule must fail. 
In Darjeeling a correspondent of a contemporary in- 
forms us that "a shoot from the axil of a leaf just 
plucked is about J to § of an inch long eight days 
after, at 20 days it is about an inch long, at 30 days 
3 inches, at 40 days 6 inches. On these Hills, if the 
pruning has been well done and weather favourable, 
the young shoots ought to be nine inches high in six 
weeks, when picking should commence. The shoots 
should not be picked off too quickly, or the tea will 
be too tippy. —South of India Observer. 
The Scarcity of Indiarubber. — Unless some means 
are speedily taken to prevent the reckless destruction 
of the rubber trees, this important and now world- 
wide manufacture will be greatly retarded owing to 
the scarcity of the raw material. The great and grow- 
ing demand for rubber has stimulated the rubber hunters 
of Central and South America to supply the same, 
but the result is, in their eagerness to meet the extra 
demands, they destroy the greater portion of the tree. 
In many places where the rubber trees were seemingly 
exhaustless a few years ago, the forests have been 
decimated. The result is that the rubber gatherers 
have to go further and further into the interior and 
to the mountains for the present supply. Unless the 
Government of Colombia and South American States 
do something for the protection and propagation of 
this valuable tree, the export of raw rubber from these 
countries will cease in a few years. — British Trade 
Journal. 
Insect-Destroyers. — Some years ago the Massachu- 
setts Horticultural Society offered rewards for a cheap 
and effectual method of destroying the rose fly or aphis. 
This brought forth a preparation in the shape of whale- 
oil soap, with the dictum that it would destroy the 
insect whatever state it was in. The recipe is to 
dissolve 2 lb. of whale-oil soap in 15 gallons of water, 
or if the soap is of a weak strength, diminish the 
proportion of water by two gallons. The method of 
using it is to strain the liquid through a fine sieve, 
when the composition is dissolved, and then apply 
with a syringe to the leaves and shoots affected. It 
is asserted that the remedy is effective also for thrips, 
red spider, canker worms, and the mildew on trees. 
As the remedy is so simple it might be applied to 
orange trees affected with scale, as at the above strength 
it ie quite innocuous to vegetable life, and as it can 
be used ad libitum any falling on thejground will act as 
a manure. Considering how troublesome the brown 
beetle is on fig-tre>-s, it might be employed in de- 
stroying those pests.— Australasian. 
Influence of Forests on Rainfall. — In the American 
Naturalist for January appears an article by Dr. 
Anders on the influence which forests exercise upon 
the rainfall. The practice of ringbarking has lately 
been advocated in Australia, on the ground that the 
amount of surface water is thereby increased, though 
this effect is not demonstrated to be anything but 
temporary — indeed, by the nature of the case, it 
would seem self-evidently so — and the effect of this 
scanty surface water upon the humidity of the atmo- 
sphere would be nearly nil. How forests affect the' 
humidity it was the object of the writer's experiments 
to show ; and his experiments appeared to prove 
that, while no moisture is absorbed by plants from 
the atmosphere, they yield to it a considerable quantity 
by transpiration of water gathered through the roots — 
the rate at which aqueous vapour is given off by 
plants amounting to more than an ounce and a 
quarter per square foot of leaf surface in the twelve 
diurnal hours. The evaporation from a forest area 
is probably more than from an equal area of water ; 
ana the conditions of the soil penetrated by the net- 
work of roots render it a reservoir of the rainfall, 
to be gradually utilised by the leaf surface above. 
This humidity imparted to the atmosphere tends to 
equalisation of temperature by preventing undue radi- 
ation of heat ; and though it cannot increase the 
general rainfall— rain being generally formed from 
one to two miles above the surface of the earth— yet 
there seems reason to believe that light local rains are 
really increased over forest land, besides the abundant 
dews by which it and its vicinity are visited. Ex- 
periments of two French observers are cited, which 
gave a total rainfall for six months over forest land 
of I92£ millemetres, and of 177 in the open air, 
showing a difference in favour of the forest of 15£. 
Tbe action of forests is, of course, more or less 
local ; and therefore their distribution, as sources of 
humidity, as well as for the shelter they afford from 
sweeping wind, is a matter of much importance.— Field. 
Bifacial Oranges.— In the Provence Agricole M. 
Heckel tells us how the fruits which on one side pre- 
sent the characteristics of Oranges, and on the other 
those of Lemons, are produced. A nurseryman at 
Cannes, M. Tordo, takes scions (bourgeons) of various 
species of Citrus, Orange, Lemon, &c, and grafts them 
circularly along the trunk of a Citrus, arranging the 
scions closely together in pairs so as to bring about 
complete fusion of the scions. When the grafts have 
adhered the tree is headed down to within a short dis- 
tance of the grafts, and in spring branches are seen 
which give rise to monstrous fruits, having the charac- 
teristics of the different grafts blended together. The 
branches which originate from the ingrafted shoots pro- 
duce leaves which are greatly changed in form and differ 
from those of either species, thus affording a striking 
proof of graft-hybridization. The flowers of the two 
species are also fused. — Gardeners' Chronicle. 
The Divi divi Plant.— The Divi-divi pods are em- 
ployed for tanning purposes, as they contain 50 per 
cent of pure tannin. I have been told that Jin Bangalore 
there is a large plantation of this tree, and that its 
pods are largely used for giving the skins that superior 
smoothness remarkable in the Madras and Bangalore 
skins. I have also used Divi-divi in dyeing, and 1 have 
employed a solution of acetate of iron after the hath in 
Divi-divi tincture. The ink used in most of the Go- 
vernment offices in Fort St. George is made with this 
plant. The cultivation of this elegant shrub is very 
easy. The seeds should be sown in March, and the 
young plants can be removed from the nursery during 
the following rainy season ; they require some watering 
till they have attained the height of three feet, after 
which no more care is necessary. This plant grows 
luxuriantly in a clayi-h. calcareous soil, but very 
slowly in red soil, as I have observed at the Red 
Hills near Madras. I think the difference in the growth 
in the two soils results from the clayish soil retain- 
ing moisture for a very long time in the summer, while 
in the latter the young plant is exhausted by the 
strong dry winds blowing then. But I think it still 
possible to cultivate this shrub in red soil with some 
success by adding dry mud from tanks to the soil 
before replanting the young tree from the nursery. 
Cow dung ashes will prove useful round the plant. 
The great difficulty to contend with, however, in such 
soil is the want of water. The cultivation I have 
made for the last few years is quite a success, and 
I have made experiments in both soils, clayey as well 
as red. I shall feel obliged if any of your readers 
will give me some information regarding the market 
current price of this dye in London or elsewhere. I 
think that the high rate of freight from India to 
Euiope will not allow a margin of profit in the ship- 
ment of Divi-divi husks.— Searcher. — Madras Times. 
