MONTHLY. 
XXIII. 
COLOMBO, MAY 2nd, 1904. 
No. 11. 
NOTES ON CASTILLOA AND PARA 
RUBBER. 
HE United States Department of 
Agriculture has shown itself to 
be one of the most practical, 
active, and wide-awaks of these 
national departments instituted 
to encourage and assist the agri - 
cultural industry of the various 
nations. Somewhat recently the 
American Bureau published " The 
Culture of the Central American Rubber Tree," an 
exhaustive work on tha Castilloa Rubber tree (Castilloa 
elastica) by Mr. O. F. Cook. This is the best work of 
the subject that has'yet appeared, and should be in the 
hands of all planters interested in Castilloa. 
In Ceylon, however, it is the Para rubber tree 
(Ecvea hraziliensis) in which planters are chiefly 
interested, and we give some extracts from the book 
just mentioned dealing especially with this tree, and 
also the Concluding Summary of the book. There is 
an appendix of 18 good plates, two of which shows a 
peculiar habit of the Castiloa tree, that of self pruning. 
When youDg the tree branches prolificly from the main 
trunk, when older these stems die off and fall out 
leaving a pitted scar on the trunk where they were first 
attached. In rubber culture the object is to produce 
a large tapping surface on the main trunk, and the 
following is an important extract. 
EFFECT OF SHADE ON THE FOBM CF THE TREE. 
There are great and persistent differences of shape 
or'hsbif among trees. The Lombardy poplar and 
the weeping willow are not distant relatives. It is a 
general fact, however, that forest trees are taller and 
more slender than those of the same species grown 
in the open. The low spreaciiug habit, which is 
desired and encouraged among fruit trees, is 
not desirable in rubber-producing species, where 
a large expanse of trunk ia needed to supply the 
milk and to give opportunity for tapping without the 
necessity of wounding the same place too often. 
Castilloa trees growing alone in the opeo often send 
Out permanent braaohea 8 or 10 feet from the ground, 
while those in the forest may have from 20 to 40 
feet of smooth trunk before the permanent branches 
are reached. Open-grown trees may have large 
spreading branches, while ia the forest or under close 
planting the main axis of the tree continues to grow 
upward and the lateral branches are relatively small. 
The problems of rubber culture may prove in this 
respect to be directly opposite to those of coffee, where 
the formation of much wooQ in proportion to leafage ia 
a sign of unfavourable conditions or of bad plantation 
management. It does not follow, however, as some 
have seemed to suppose, that forest shade is necessary 
to grow long-trnnked tree?. 
In coffee culture it is plain that the most wood is 
formed not by shade culture, but by planting close in 
the open, and the folder planted trees of Castilloa at 
La Zacualpa, if not as slender and as smooth-trnnked 
as those of the forest, are certainly tall and slender 
enough to furnish ample evidence that open culture 
does not cause a low, spreading growth, if the trees 
stand close enough together. The Zaoualpa experi- 
ment is of further eignificanoe in this connection, 
hecause it shows that a harmful degree of crowding 
was hy no means reached. In numerous instances 
where from three to five trees grew in a cluster their 
trunks weie eash equal in size to those of many of 
their neighbors which stood alone. 
Coffee trees which stand too close together lose the 
use of their lower branches, which become interlaced 
and shade one another, and ultimately only the top of 
each tree continues to grow and produce fruit. The 
planter must choose a middle course between the 
injury of his bearing trees by crowding and the waste 
o£ capital and labour in keeping clean unused land 
between trees planted too far apart. With the rubber 
tree the seed is a consideration entirely secondary to 
the growth of the trunk. In comparison with coffee it 
may be said that the crowding of rubber trees is 
desirable, and that it finds its limit, not in the dis- 
couragement of lateral branches, nor even in the 
lessening of the size of the individual trees, but in the 
decrease in the amount of rubber which can be pro- 
duced on a given area of land. 
