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II. Plantation rubber.
Rubber from the plantations is always preferred in international trade; it is natural therefore, that, in addition to the measures which have been suggested to encourage the production and facilitate the exportation of quality A., the question of planting rubber trees should also have been considered.
In 1895, a nursery of Ceara (Manihot Glaziovii) was made at Sedhion and, in view of the threatened disappearance of rubber lianas, it was contemplated using Ceara, as a certain number of seeds and of plants existed on the spot.
These trees multiply very rapidly, but unfortunately their prolificness is counterbalanced by the injury caused by the forest fires due to the carelessness of the natives. The Ceara must be some years old before it can resist fires, so that the species seldom passes the limits of the forests.
Few reliable data exist as to the best age for tapping and on the yield of rubber, as well as regarding the best system of operation. It seems, that an adult tree gives from 8 1⁄2 to 10oz. of rubber per tapping and in the dry season between January and June, a collector does not obtain above 8 1/2oz. a day. In these districts, the Ceara comes into leaf in July, and the tapping done from July to January would be more lucrative than that undertaken during the dry season when the incisions cicatrise badly, owing to the hot east winds, and sometimes bring about the death of the tree. Thus the winter tapping is best.
The operation should be carried out by means of horizontal or vertical incisions, but fish-bone or V shaped cuts must be avoided, as they are injurious to the tree.
Other rubber trees.
The Ceara is not the only rubber tree which thrives in Casamance. Experiments made at Martinique with Funtumia seem to show that this tree also could be advantageously grown; it is very hardy and would resist the scorching winds well, its bark being less delicate than that of Ceara; further, its general appearance and greater supply of latex are also advantages over the latter tree. The observations made at the Agricultural Station of Mangacunda seem to confirm these views.
Funtumia and Ceara are trees suitable to averagely damp districts; but in plantations of some extent, inequalities of the ground are to be met with, where during the winter rains actual swamps occur; in these Ficus elastica can be planted with advantage. As for Hevea brasiliensis and Castilloa, it can only be said that the experiments made at Mangacunda do not appear to be conclusive.
Year, No. 115, pp. 327-330. Paris, October 1912
In order to assist all those who desire to try cultivating tobacco in the colonies, the Colonial Garden of Paris has asked for and obtained a series of instructions, drawn up by the International Commission of Colonial Tobaccos, of which the following is a summary:
Conditions for the production of light Tobaccos.
a) Selection of varieties. Those varieties that in their country of origin possess a low nicotine content.
b) Soil. Light permeable soils without permanent moisture are to be preferred.
c) Manures. Nitrogenous manures stimulate greater development of the leaves, greater thickness of the tissues and higher nicotine content. Potash on the contrary produces finer and more pliable tissues.
d) Density of Plantation. The nicotine content is lower the closer the plants are to each other. The weight of the crop increases with close planting. Experiments made at the Colonial Garden in 1911 have shown that the weight of the crop increased by 60 per cent when 17 000 plants were grown on an acre instead of 8 500. For the production of light tobaccos
it is therefore profitable to increase the number of plants per acre.
e) Number of leaves. The nicotine content is in inverse ratió to the number of leaves, while the weight of the crop is in direct ratio, reaching a maximum between 15 to 20 leaves.
Conditions for the production of combustible tobaccos.
The variety is to be determinrd by trials of the combustibility of the leaves, and the soil that is selected must have sufficient assimilable potash; if it should be deficient in potash, this element must be added. For the reasons given above, if a heavy crop of tobacco with low nicotine content is desired, it will be necessary to ascertain by experiments with each variety which are the optimum conditions of closeness of planting and of number of leaves, on the plan given below:
These figures hold good for Maryland, Burley, light Kentucky and other fine leaved varieties, Sumatra, Java, etc.
Conditions for the production of Nicotine Tobaccos.
According to experiments conducted in France it appears that the maximum of nicotine for a given area is obtained under the following conditions: 1. Leaving 6 or 7 leaves per plant.
2. Setting the plants at such a distance as to cover the soil without the leaves injuring each other. With the Lot variety this has been obtained by 8 100 plants per acre, with Sufi 12 100 per acre. The density of the plantation varies with the vigour of the plant, the climate and the soil. Experiments may therefore be made on the following plan:
The subsequent cultivation is the same as for the fine tobaccos, only the pinching off of the side shoots requires special care.
No. 115, pp. 331-333. Paris, Oct. 1912.
The type-species Coffea arabica is the origin of four varieties, which have very different and transmissible characters and are all cultivated in the Yemen. These are:
"Matari," a plant with very small berries, which is cultivated between the towns of Menakha and Souk-el-Khemis, at an altitude of about 2 000 feet; this is the most renowned of the Arabian species of coffee.
2. "Haïni." This much resembles the latter, but has larger berries. 3. The "Kérési" and "Cohlaru" varieties yield very good berries,
but their quality is inferior to that of those borne by “Matari.”
The Yemen includes two very different districts, both as regards the nature of the soil and the climate. From the shores of the Red Sea to the moun
tains of Central Arabia there extends a vast sandy desert belt about 62 miles wide, called the "Theama," consisting of recent alluvium, which surrounds the second district. This has a warm-temperate climate and is remarkably productive. The temperature here varies from 14 to 26oC. in the day and drops to 22oC. at night during the summer. In winter, the thermometer drops to -1 and -2oC. at night, and rises in the day to 29oC., a higher temperature than it reaches in summer. The irregular rainfall amounts annually to from 800 to 2 000 mm. (32 to 80 inches). In this district, coffee plants are cultivated on terraces, which extend in steps from the base of the valleys to the highest summits. The natives have used all the primitive means at their disposal to retain the water and supply the soil necessary for the plants. The areas of these terraces necessarily vary according to the height at which they are made; the largest may be from 1/8 to 1/, of an acre; there is about one coffee plant per square yard. The coffee plants are cultivated at between 4 000 and 6 600 ft., in large and deep ravines sheltered from the wind. These clefts are a characteristic of the geological formation of the mountains.
The coffee plants are given no manure; sometimes, when it is possible, the native irrigates the plantation, but more usually, he digs basins around each stem; these are united by a channel, in order to utilise and equally distribute the rainwater. The coffee plant is never pruned; the native merely ploughs the entire terrace before the awakening of vegetation and replaces the soil when the rain washes it away. The bad state of the plantations and the little care given to them cause the crop to be much inferior to that which could be obtained by systematic cultivation. The harvest takes place in December, and after a short preparation the coffee is transported on camels to Hodéidah, or to Aden, where Europeans prepare it for exportation to Europe. A shrub called Gath" is sometimes cultivated together with the coffee plant; the young leaves of the former are used for chewing and contain small glands, which secrete a sugary liquid with excellent properties due to the presence of an alkaloid, which is probably analogous to cocaine.
34 A Table Summarizing the Properties of the Different Vine Stocks of adapting themselves to Different Soils.
BURNET, J. Tableau résumant les facultés d'adaptation des differents porte-greffes aux differents terrains. La Petite Revue Agricole et Horticole, Year 18, No. 430, p. 247. Antibes, November 10, 1907.
Nature of the Soil.
Non-calcareous soils, provided they are not too dry, or shallow, or too damp, limit of lime 20 per cent, rather light, or semi-light.
Riparia Gloire de Montpellier.
The same soils, but dry, though not exclusively (Rupestris X Cordifolia 107-11. limit of lime 15 to 20 per cent.
The same soils, not excessively dry, lime limit 20 per cent.
Cordifolia X Riparia 125-1.
Riparia Grand Glabre, Rupestris
X hybride Azémar 215-2, Aestivalis X Riparia 199-16.
Same soils, not excessively dry, lime limit up to Riparia × Rupestris 11 F, Ripa25 per cent.
Same soils, not excessively dry, lime limit 25 to 30 per cent.
The same soils, not excessively dry, lime limit
30 to 40 per cent.
› ria × (Cordifolia ×Rupestris) 106-8. Riparia X Rupestris 101-14. Rupestris X Riparia 75-1. Rupestris X Riparia 108-103. (Cinerea X Rupestris de Grasset) X Riparia 239-6-20. Riparia X Rupestris 101-16. Riparia du Colorado..
Ground with stones and soil mixed, provided they answer to the following conditions.
Soils apparently dry but deep, being neither damp nor dry, especially as regards the sub-soil. Having good warm exposures-slopes.
Heavy soils, which cake, argillaceous, containing on analysis a large proportion of fine sand (which occurs in the case of many soils of glacial clay). Lime 20 per cent.
Lime 25 per cent.
Lime 25-35 per cent.
Lime 40 per cent.
Lime 45-55 per cent.
Soils containing more than 55 per cent. of lime, provided that there is no stagnant moisture in the subsoil.
Soils compact, or not, with 25 to 30 per cent. of lime, very damp.
Soils very dry to great depths, non-calcareous.
Soils very dry to great depths; calcareous.
If they have not more than 20
With 30 to 40 per cent. of lime.
Berlandieri X Riparia 420 A.
Riparia X (Cordifolia X Rupes-
The last may be tried up to 25
Riparia X Rupestris IOI-14.
Mourvèdre X Rupestris I 202.
Chasselas X Berlandieri 41 B.
Solonis Riparia 1616.
Riparia X (Cordifolia X Rupes-
Cordifolia X Rupestris 107-11.
Bourisquon X Rupestris 603.
For some stocks which have not yet been tried in France from the point of view of chlorosis, viz. Riparia X (Cordifolia Rupestris) 1068 etc., the writer fixes a lime resistance limit according to the vine-growing literature of other districts.