GENERAL CONDITIONS.
Vanilla cuttings are said to have been first introduced into the Seychelles Islands in 1866, probably from Bourbon (La Réunion), where the plant was grown extensively after sugar began to fail, about 1850. Plantations were gradually established and extended by the multiplication of these original plants and from others subsequently imported, and for many years now the colony’s prosperity has largely depended on vanilla.
If kept free from disease it is a plant of extraordinary vitality; and here, where moisture and heat, its main requirements, are both ample, the sort of soil it is grown in seems to be of no great importance, provided that, if it be very poor, the roots are kept well supplied with manure. It is cultivated in the Seychelles from near sea level to 1,800 feet altitude, and does well (except for disease) at all altitudes between these extremes.
The rainfall is generally about 100 inches—that is in Port Victoria, which lies low; in the hills the precipitation is probably from 10 to 30 per cent greater; and in drier districts, away from high lands, where little timber is left, it must be considerably less. The fall is fairly evenly distributed throughout the year, but a dry spell, which is necessary to bring vanilla into flower, is to be looked for in July, August, or September, while the heaviest rains most frequently come in December. Even where rain has not fallen for some time the air is very moist, and for want of more exact information on this head it may be stated that, generally speaking, in the hills common table salt will deliquesce in a day or two if left uncovered. The range of shade temperature for day and night, from sea level to 1,800 feet, may be put at 90° to 70° F. The former is exceptional, the latter frequent, especially in early morning when the monsoon is blowing. Occasionally 68° may be registered, but seldom lower. Of soils, three very different sorts may be mentioned, in all of which vanilla does well here: (1) Rich vegetable mold, common enough in forest land as a thin surface skin, and also occurring deeper in valley bottoms. For a quick growth this is excellent. (2) A greasy red clay, also in fair quantity, on which vanilla makes good growth. (3) Coarse quartz sand, or gravel, apparently derived from disintegrated granite, not common, but met with in considerable patches here and there. Though so unpromising to look at, this is, perhaps, the best of all. It gives free drainage to the roots, and in wet years plants fixed on it are more likely to crop than those on closer soils, while with ample manuring they grow remarkably well.
The manner of setting out plantations in the Seychelles has undergone changes within the last twelve years. Formerly plantations were seen with the rows of vines planted so close together as scarce to leave room for workers to pass between them. The yield per acre under such conditions was sometimes enormous, but when disease once started in a vanillery thus arranged its destruction was rapid and complete, so this system has been mostly given up. Since the loss of so many close-lined plantations the distance between the rows has been increased. Living wood, i. e., small trees, are used as supports for the vines, these being festooned from fork to fork; but many planters have made use of hard-wood posts and bars, the former being notched on top and the latter laid in the notches, resting thus from 4 to 6 feet from the ground, according to fancy. Over these bars the plants are hung (Pl. 1), being looped up as growth is put on. Wire is sometimes also used instead of horizontal bars. It is much cheaper, but otherwise has disadvantages, notable among which is that it sways with wind and is liable to break the vines, the curvature being too sharp over such a small round surface. However, when plants thicken into a mass this last drawback mostly disappears.
A third, and, as the writer believes, much better way of growing vanilla, is now more generally coming into practice. This is to plant each creeper on a tree of its own, and where land is cheap it is an advantage if these are well apart. So arranged, the general maintenance of a vanillery is certainly more expensive, inasmuch as isolated plants require more manure than when the same number are closely grouped together. The work of flower pollination and crop gathering is also more laborious. But more than a counterpoise to these disadvantages is the increased security this method of planting gives against wholesale destruction from disease; for when so arranged a sick plant can be removed and destroyed with greater chance of this being done before any of its neighbors become affected; whereas when growths of different plants are interwoven, either in their roots or shoots, it is difficult to know when enough has been taken up, and there is every likelihood of the disease becoming established beyond control.