Sept, i, 1897.] 
THE TROPICAL AGRlCULTURiSP. 
155 
trees, I speak on the authority of Mr. Hart, f.l.s., 
of the Botanical Gardens, Trinidad. 
In March of last year I visited a plantation in 
Chontales, which, strange to say, is the result of 
native enterprise. It then comprised one thousand 
trees, well developed, of hardy appearance, and as 
large as a good-sized apple tree. An early maturity 
seemed assured. 
Seiior Romero, Mexican Minister to the United 
States, in an article pnblished in the India-ruhher 
World (New York) for April 1892, estimates that 
each sixty-year-old tree, planted at intervals of fifteen 
feet, will have cost eight cents U.S. currency, and 
will yield six pounds of rubber. Other authorities 
fix the yield at maturity as high as fotirteen pounds 
of rubber. It depends on whether the season has 
been wet or dry, and whether the trees are well 
or badly cultivated. 
In order to be on the safe side, I propose to 
estimate the cost to the end of the eighth year 
at 18 cents U.S. currency, or 9d. per tree, and the 
eighth year’s average yield at five pounds of rubber. 
The market price of good Central American rubber 
is 2s. 4d. per lb. Para rubber fetches from 2s. 3d. 
to 3s. 6(1. per lb.; and if gathered and coagulated 
in the same cleanly manner, rubber produced in 
Nicaragua should be worth as much. Nevertheless, 
I prefer to estimate on a selling-price basis of 2s. 
per lb. only. The result at the end of the eighth 
year of an acre plantation comprising 193 trees 
planted fifteen feet apart would be as under, includ- 
ing the premium of ten cents native currency — 
say 3d. — per tree paid by the Nicaraguan Govern- 
ment. 
Dr. 
Cost of cultiva- 
tion for the 
term of eight 
years, with seed, 
&c., cf 193 trees 
at 9d. each £7 4 9 
Cost of tapping or 
harvesting 3 0 0 
To balance 88 13 6 
Cr. 
Government pre- 
mium of 3d. per 
tree £2 8 3 
Yield of 193 trees 
at the end of 
the eight year 
— 965 lb. at 2s. 
per lb 96 10 0 
£98 18 3 
Profit £88 13 6 
£98 18 3 
I arrive at the cost of tapping, or harvesting, in 
the following manner : A hulero, working in the 
dense, overcrowded forest, can tap four wild, creeper- 
grown trees in a day ; therefore it stands to reason 
that, in a plantation where the trees are weeded 
and cleaned of all superfluous growth, he could tap 
five at least, and also plaster up the cuts with mud. 
Thus the 193 trees would occupy him 39 days. A 
mozo in Nicaragua is well paid if he earns fifty 
cents native currency, or say Is. 3d. per day, but 
I have calculated bis daily wage at rather over la. 6d. 
Supposing that the plantation comprises five hundre(3 
acres, then, on the above figures, the eight year’s 
profit would amount to the enormous sum of £44,337, 
10s. And the yield increases every year, with no 
outlay except for weeding and harvesting. 
The gross capital expenditure for the eight years 
I estimate as under : 
Cost of 500 acres of laud at 6s. per acre. £125 0 0 
Surveying and procuring titles thereto. 100 0 0 
Clearing land for planting 1000 0 0 
Collecting seed and planting 500 0 0 
Eight yearly weedings at £200 each 1600 0 0 
Extras, implements, &c 300 0 0 
£3625 0 0 
Interest on £3625 for eight years at five 
per cent, per annum £1450 0 0 
Planter’s expenses, cost of living, &c., for 
eight years at £200 per annum IGOO 0 0 
Cost of gathering the eight year’s crop. 1600 0 0 
£8176 0 0 
I have included in the above the cost of maintain- 
ing the planter during the eight years that should 
elapse before the Castilloas are tapped; but it 
should be borne in mind that when the trees are 
planted fifteen feet apart, coffee, sugar-cane, cotton, 
cacao, and other sha(Se-loving plants, yielding yearly 
crops, may be grown between them, and their pro- 
duce should maintain the planter. But adding five 
percent, interest, the planter’s expenses, and the cost 
of harvesting, there still remains a net profit of 
£36,162, 10s. Estimating the value of the ninth year’s 
yield at £50,000, and deducing £200 for the annual 
weeding, £1,500 for the cost of harvesting, £180 for in- 
terest, and £500 for the planter’s expenses, the net pro- 
fit for that year will amount to £47,620, which is a 
pretty good return for a net capital outlay of £3,625. 
Of course it will be necessary to maintain a nursery 
of young plants to fill vacancies caused by accidents 
and replace trees when their rubber-bearing life is 
over ; but the cost of such a nursery would not be 
great. And one must not count on the Government 
premium being paid in perpetuity. 
In reference to the life of a rubber tree and its 
increasing productiveness, the following extract from 
Tlte ITorld (New York) of 21st August 1892 will be 
of interest: 
‘Three young trees transplanted from the forest to 
a cultivated field in Soconusco, Mexico, are now 
said to be seven feet in diameter, and have yielded 
rubber for more than thirty-five years ; the present 
product averaging more than fifty pounds of gum 
per year.’ The average increase is generally esti- 
mated at one pound of rubber for each year of the 
tree’s life up to a certain age, which, however, I am 
unable to fix. 
On the eastern side of Nicaragua, and especially 
in the Mosquito territory there are immense tracts 
of laud suitable for the cultivation of Castilloa 
elostica. In choosing land, shelter from strong winds, 
the greatest enemy of young Castilloa, should be kept 
well in view. The seeds should be sown in a nursery 
bed shaded from the mid-day sun, and the young 
plants transferred to the hacienda when twelve months 
old. For each plant a hole should be dug three feet in 
diameter and one foot deep, and filled with fine loamy soil 
to which a little sand has been added. The mixture 
should be well-trodden down and watered night and 
morning for two days, when it is ready for the 
young Castilloa, which must be placed in its new 
bed at exatrtly the same depth as in the nursery ; 
if it is weak, a stake support is very desirable. 
Trees tapped in the wet season are estimated to 
yield five times as much milk as in the dry. The 
quantity of rubber produced therefrom depends to a 
great extent on the coagulating agent employed. 
Sixty per cent, of the milk ought to be turned into 
rubber. A very good agent is one ounce of alum 
dissolved in sixteen ounces of water. But a weak 
alcoholic solution will give even better results, for 
the process is immediate, and the solution may be used 
many times. In my own experiments I never lost 
mose than forty per cent, of the bulk, and often only 
thirty-five per cent. 
That the cultivation of Castilloa elastica is worth 
the attention of the thousands who are seeking really 
remunerative investments there cannot be the 
slightest doubt, and this the author intends to show 
in a work on the whole subject of india-rubber which 
he hopes to publish shortly. For success careful study 
and inquiry is imperative. — Chambers’s Journal. 
THE DISEASES OF PLANTS. 
Throughout a long series of years the pages of 
the Gardeners’ Chronicle have from time to time conveyed 
much information regarding the diseases and ills 
connected with plant life — and its work continues, 
for the foes still advance. Now-a-days, however, 
the prevention and remedy of disease come more to 
the front, and naturally this aspect appeals to the 
cultivator of plants. 'Tiiere has never been any 
lack of suggestions for the cure of disease in our 
gardens ami plant-houses, yet within the last ten 
years of thereabouts, remedies may be said to have 
showered on us at all times and in all kinds of 
gardening periodicals, till one feels lost in the numbers, 
