A restriction with regard to the time of buying the July—August crop is recommended for adoption by the merchants, in order to prevent immature, insufficiently dried corn being shipped. It is insisted, however, in some quarters, that, until the holds of ships are systematically cleaned out before loading, no amount of precaution on shore will prevent shipments becoming weevilled during the voyage. (See article on “The Cultivation and Marketing of Maize” in the Bulletin of the Imperial Institute, vol. vi. [1908], pp. 261-77.)
Experiments were carried out in 1911, 1912 and 1913 to determine the most profitable time for sowing maize. The results were, however, conflicting, and no definite recommendation could be made owing to the irregularity of rainfall.
CASSAVA.—Among the more important field crops, cassava has to be reckoned. Two well-marked forms occur, which are readily recognised by the different characters of their leaves, one having the leaflets digitate and pointed, and the other digitate and spathulate, with the central leaflet shortened. Cassava forms an important food in many parts of the country, and is widely cultivated, especially in the Western Province. No tapioca is prepared from the root in Southern Nigeria, such as is the case in the West Indies and elsewhere.
YAMS.—In many parts of the country, more especially in the Central and Eastern Provinces, the various forms of yam (Dioscorea) are extensively cultivated alone or with maize, but the presence of five or six other crops growing upon the heightened yam mounds is not uncommon, in the Cross River districts particularly. From the latter locality quantities of yams are sent by river canoes to the large ports in the vicinity of which cultivated land is often scarce.
The Koko yam (Colocasia antiquorum) is also common in the wet zone.
GROUNDNUTS.—The cultivation of groundnuts (Arachis hypogea), upon a more extensive scale than at present, is to be recommended, as there are too few leguminous crops grown in the local rotation. The colour of most of the Southern Nigerian nuts is probably an obstacle to their ready sale in Europe; the shell being usually a dirty greyish instead of a light straw colour. The kernels are, however, satisfactory. It would, perhaps, therefore be advantageous to ship decorticated nuts, as is done in the Northern Provinces. Although new seed and instructors have been brought recently from the Gambia, very little more is grown than formerly.
The variety seen in the Western Province is a larger one than that of the Gambia, and has generally two kernels. The market price for groundnuts at Lapita near Oyo was 200 for 1d., which will indicate the scarcity of the product.
SHEA NUTS AND BUTTER.—The export trade in shea nuts (Butyrospermum Parkii) was expected to develop with the extension of the railway through Ibadan and Ilorin to the Northern Provinces, but the exported product still has its main source from localities north of the Niger. The demand does not seem sufficient to induce expansion to a great extent (Bull. Imp. Inst., vol. vi. [1908]).
The butter or fat is much appreciated in the country for culinary purposes, and has been found of value in Europe for soap and candle-making, as well as for the manufacture of vegetable butter.
KOLA.—Two species of kola (K. acuminata and K. vera) are cultivated, the latter being the indigenous Gold Coast form, the fruit of which is said to be especially valued in the Haussa countries to the north. The local native names are, respectively, “Obi abatta” and “Obi gbanja.” In general appearance the trees are similar, except that the former has narrower and smaller leaves. The “gbanja” form of nut is generally pink and divisible into from two to three parts (cotyledons), whereas the “abatta” form may vary in colour from deep crimson to white and be separable into from three to five parts. The price paid for kolas in Lagos is said to vary from 1s. 3d. to 5s. per hundred.