The agricultural and forest products of British West Africa

by Gerald C. Dudgeon

Fungoid Pest.—A sooty fungoid growth is sometimes seen upon the leaves, similar to that occurring on orange trees in the country, and probably belongs to the genus Meliola. It is destroyed by the application of sprays of Bordeaux mixture.

Rubber Machinery.—A fully equipped installation of rubber-washing and crêpeing machinery was exhibited at the Kumassi Agricultural Exhibition of 1908, and was subsequently taken over by one of the leading mercantile firms at that place, where the local rubber is now washed, crêped, and pressed before export. It might prove advantageous to come to an arrangement with the rubber collectors to bring the latex to Kumassi, where, under proper supervision, it could be made into rubber of high quality. As the latex will remain for a considerable time without alteration, it should not be difficult to bring it in from places several days’ journey distant.

Vine Rubber.—Several species of vines, belonging to the Natural Order Apocynaceæ, produce rubber in Africa, but the only one of commercial importance occurring in the Gold Coast is Landolphia owariensis, Pal. Beauv., from which “Krepi” or “White ball” is obtained. Unless the plant is observed during the flowering as well as the fruiting season, it is difficult to distinguish it from some nearly allied, but useless, species of the same genus, which are found commonly in the same localities.

The vine is found throughout the forest region of the Gold Coast and Ashanti, climbing over and interlacing the main branches of large forest trees; but an apparently terrestrial form of the same species has recently been discovered in the ultra-forest region, where the stunted habit in which it grows is probably occasioned by the annual grass fires.

Under different atmospheric conditions the latex of L. owariensis behaves differently. In the drier regions it coagulates upon the wound almost immediately upon exposure to the air, whereas in other and moister places it runs from the cut in such a manner as to allow it to be collected in a vessel. The acid juices of some of the local wild fruits are added to hasten coagulation, when this is necessary, or the collector is said to smear the fresh latex upon his naked body, until enough has been coagulated to form a small ball, which serves as a nucleus for winding on the strings of fresh latex as the new cuts are made. There is a quantity of “scrap rubber” formed on the wedge-shaped cuts which it is usual to make, and this is added to the ball, which attains a diameter of three or four inches when complete. The crushing of the root and stem for the manufacture of so-called “root-rubber” does not appear to be practised in this country, although common elsewhere in West Africa.

On account of the colour and form of this rubber, the name of “White ball” is usually applied to it, although, from the fact that the Krepi tribes, living on the east bank of the Volta river, produce a large quantity of it, the name of “Krepi ball” is frequently given.

White ball rubber is seldom adulterated by the addition of other latices, as these would retard coagulation and interfere with the preparation of it in the manner mentioned. For this reason the rubber sold under this name usually obtains a higher price than other rubber.

Landolphia owariensis presents many disadvantages for cultivation in plantations, and the yield is small in proportion to the space which the plant occupies. Several species of this and allied genera are being grown experimentally at the Aburi Botanic Gardens.

“Flake rubber” is a name given to a very inferior quality of rubber which is produced upon a small scale in many parts of West Africa, but it has not been determined from which species of vine that exported from the Gold Coast is obtained. In Northern Nigeria Carpodinus hirsutus, Hua, is said to be the source of the exported rubber of this name.

Fig Rubber.—One or more species of wild fig trees (Ficus sp.) are tapped for the production of what is locally termed “Memeluku” rubber, and it is generally supposed that F. Vogelii is that mostly employed. The trees attain a large size, and the rubber is composed of the scrap, collected from a large number of small cuts made on the trunk and branches. This scrap rubber is pressed together into thick biscuits. The rubber has usually little resiliency and breaks easily; it is, in consequence, of small value.