Part 1

Bulletin No. 21, Division of Botany. PLATE I.

[Illustration: FIG. 1.--VANILLA IN FLOWER--SOME OF THE FLOWERS ALREADY GROWN INTO SMALL PODS.]

[Illustration: FIG. 2.--VANILLA IN FAIR CROP, ON BARS AND POSTS UNDER SHADE.]

BULLETIN NO. 21. S. P. I., No. 2.

U. S. DEPARTMENT OF AGRICULTURE, DIVISION OF BOTANY.

VANILLA CULTURE AS PRACTICED IN THE SEYCHELLES ISLANDS.

BY

S. J. GALBRAITH.

[Illustration]

WASHINGTON: GOVERNMENT PRINTING OFFICE. 1898.

CONTENTS.

Page.

Introduction to Mr. Galbraith’s paper, by D. G. Fairchild 7

General conditions 9

Starting a vanillery 10

Preparing the vines for cropping 13

Pollination of the flowers 15

Curing the pods for market 17

Miscellaneous information and notes 21

Summary 23

ILLUSTRATIONS.

PLATE.

PLATE I. Page.

Fig. 1, vanilla in flower--some of the flowers already grown into small pods; fig. 2, vanilla in fair crop, on bars and posts under shade Frontispiece

TEXT FIGURES.

FIG. 1. Hand pollination of the vanilla flower 16

FIG. 2. Plan of curing house 19

INTRODUCTION TO MR. GALBRAITH’S PAPER.

By D. G. FAIRCHILD.

The following paper on vanilla culture has been prepared by Mr. S. J. Galbraith, of Mahé, Seychelles Islands, who was for some time associated with Mr. W. T. Swingle, agricultural explorer of the Section of Seed and Plant Introduction, in the preparation of a joint memoir on the culture and disease of vanilla in those islands.

As the second part of the report, which deals with the disease, has not been completed, it seems desirable not to delay longer the publication of this part, relating to vanilla culture, inasmuch as it is practically complete in itself.

Although the vanilla is a plant native to America, its culture is now carried on most extensively and successfully in Bourbon, Seychelles, Mauritius, Madagascar, and other islands lying in the Tropics in the Indian Ocean east of Africa, as well as in the Island of Tahiti in the South Pacific.

The vanilla industry is a very important one in the Seychelles Islands, and Mr. Galbraith, himself for many years a successful planter, is in a most favorable position to write on the subject of vanilla culture.

The vanilla is a climbing orchid, the nearly mature pod of which is the part known to trade and that which furnishes vanilla flavoring. The plant grows wild only in the Tropics, and is so sensitive to cold that its culture can be successful only in regions absolutely free from frost.

The recent annexation of the Hawaiian Islands, Puerto Rico, and other tropical territory has added to our domain regions which there is reason to believe will prove admirably suited to the cultivation of this plant.

The competition of artificial vanilla, prepared synthetically by chemical methods, has not proved to be of any considerable importance. Indeed, the price of good vanilla has risen during recent years probably because of the ravages of disease in the islands where it is principally grown.

Prospective growers will be greatly aided in finding suitable climates and soil by Mr. Galbraith’s recommendations on these points.

The disease mentioned in various places in this bulletin is the one described in the second as yet unpublished part of the original memoir. It is of fungous origin, of great destructiveness, and spreads during moist hot weather very rapidly, frequently causing total destruction of large plantations in a month. During recent years it has seriously crippled the vanilla industry in Seychelles, Bourbon, and other islands of the Indian Ocean. This malady spreads with extraordinary rapidity where plants are crowded and allowed to intertwine, and for this reason Mr. Galbraith advises against close planting, though in regions free from the disease such culture might well prove more profitable than the methods here advocated.

Without going into details, it may be unhesitatingly affirmed from the results of Mr. Galbraith’s very thorough and painstaking studies that the malady is of such great destructiveness, spreads so rapidly, and is so difficult to control, that it would, if ever introduced, ruin probably forever the prospects of successful vanilla culture in our new territories.

_It becomes, then, a matter of absolutely vital importance to keep the disease out of Hawaii and Puerto Rico if it is ever proposed to grow vanilla there._

No surer method of destroying in advance the hope of establishing this highly profitable industry could be conceived than that of carrying out the first thought that would occur to an enterprising prospective cultivator, viz, of sending to the islands of the Indian Ocean, where vanilla culture is most highly developed, for a stock of plants to use in starting a vanillery.

The only possible way of safeguarding our new domains against this disease is to prohibit absolutely the introduction of living vanilla plants except by the Government, and then only after inspection by a competent plant pathologist.

Fortunately vanilla plants may be multiplied very rapidly if placed under favorable conditions, and from a small stock of disease-free plants it would soon be possible to stock all the islands.

The Secretary of Agriculture proposes to secure such perfectly healthy plants for distribution to planters wishing to experiment with vanilla culture, and it is hoped that meanwhile, in the absence of any definite legislation on the subject, public opinion will prevent any promiscuous importation of vanilla cuttings.

As soon as the plants begin to yield pods the services of an expert should be secured to superintend the curing, for which specially constructed apparatus is required, and to report on the quality of the product.

There is every prospect for the successful establishment of vanilla culture in Hawaii and Puerto Rico, provided suitable soils and climates be found, and provided the disease be excluded. Certainly an industry which yielded to the small island of Tahiti in 1897 $172,295, to the Seychelles $246,600 in 1897, and to Réunion $560,563 in 1892 is worthy the serious attention of prospective cultivators. The desirability of publishing a practical paper on the subject at this time is emphasized by the conviction that both Hawaii and Puerto Rico offer suitable fields for the introduction of this industry.

VANILLA CULTURE AS PRACTICED IN THE SEYCHELLES ISLANDS.

By S. J. GALBRAITH.

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.

STARTING A VANILLERY.

To give some notion of how a vanilla plantation is set out and carried on in this colony, it will be convenient to assume that the tree method of planting is the one adopted. A great variety of trees will serve the purpose. Here, on most properties, there is an abundance ready for the work; but of course where this is not the case suitable trees must first be planted. In selecting trees those should be chosen which do not grow too large, but give moderate foliage (about half shade) without ever losing all their leaves at once, and having plenty of branches from 5 to 7 feet from the ground, affording forks enough to train the vines through.

No hard and fast rule can be laid down as to the distance trees should be kept apart. Here formerly, as above stated, vanilla was grown in dense masses with great success for a time. Elsewhere it may be advantageously so grown now. However, it is safe to state that overcrowding in any kind of planting invites disease, and the farther plants are kept apart the more likely are they to remain healthy. A 4-foot radius would be a moderate allowance for the roots of a vigorous vanilla plant, and if 1 foot is kept clear around the circle allowed to each plant’s roots this would give 9 feet as the distance between the trees. It would be difficult to insure the plants being kept distinct in less space. Where suitable trees are already growing on the land to be planted, these can be thinned out if too close, or they may be left in small lots of three or four or more together, a sufficient clear space intervening between each lot; but in that case if one vine of a group showed disease the whole would have to be removed. Many trees stand topping, and it is a great advantage when they do, for on being cut 7 feet or so from the ground branches spring from near the cut part at a convenient height, and the best situated of those can be chosen to train the vines through, the rest that grow awkwardly being removed. About 5 feet from the base is low enough to allow any to grow.

Trees being in readiness, planting may be done at any time of year here. If during a wet spell, vanilla will sprout all the quicker; should it be dry, the plants will delay a little, but there is no fear of their missing if properly planted, and the one danger point to guard is where the vine leaves the earth. This part of the vine is burnt through if not shaded with grass or leaves. However, this also would only mean a little delay in the start of growth; for though they take some time longer about it, vanilla cuttings will grow well enough if merely tied to the trees with their lower ends some inches clear of the ground. Illustrative of the extreme vitality of plants under adverse conditions, it may be mentioned that in neglected plantations, where the vines have been allowed to climb well up into the branches of good-sized trees, and then been broken in attempting to get them down, the broken portions, sometimes partly swinging free, have remained green and capable of growth for upwards of a year, sending down long aerial roots 15 or 20 feet in length, and in some cases where these have escaped injury the broken plant may reestablish connection with the soil and start to grow again. If planted clear of the ground and merely tied to the supporting tree, it is advisable to tie two or three large leaves round each vine for the distance of 3 feet up; thus shaded the aerial roots quickly burst through the stem, and, getting something to cling to at once, soon make their way to earth without injury.

In starting a new vanillery, where the estate has no plants these are readily purchased here at small cost. From 2 to 3 rupees (55 to 90 cents) per 100 fathoms is the usual rate for cuttings, the fathom being what a man can span with outspread arms, a good sweep of the vine hanging in a curve between his hands. Where choice is possible, although oldish cuttings will grow pretty well, it is best to have the plants of recent growth; in fact, growing shoots, cut off close to where they spring from the parent vine, are preferable. At their point of origin the nodes for some distance are close together, and though roots will strike from any joints, they have a natural tendency to do so quicker at the shoot’s base. As to the length of cuttings to plant, opinions differ; but there can be no question that the longer cuttings produce cropping plants sooner than the short ones. If a 2 or 3-foot branch is planted, the shoot it gives is invariably more slender and slower of growth than would be that from a 6-foot cutting, and up to 10 or 12 feet every advantage lies with the longer plants, except the additional expense.

The question as to whether cuttings of that length are to be planted whole or divided into two or three plants should be settled by their cost. It is usual here to loosen the soil with a hoe where vanilla is to be planted, and bury the end, laid horizontally, an inch or two in the earth. Quite as good a way is merely to press the lower part of the plant into the soft soil until it is flush with the surface. On sloping land loosened soil washes away sooner with heavy rain, and in such situations it is best to leave the ground quite undisturbed. In any case the leaves on that part of the vine which rests in or on the ground are cut off fairly close to the stem, and an arm full of leaves, fern, grass, or forest sweepings laid on top to the depth of 3 or 4 inches, for a couple of feet around the plant. Its roots will not need to be mulched for a greater distance than that for some months to come, and to cover a larger area would be useless. As new top dressings are laid on, which must be done when the first supply rots down and becomes thin, these can be gradually extended to allow of more root spread, till the limit of 4 feet radius is reached. If well covered, the roots do not run much; only starved vines run far with their roots, seeking nourishment; where this is plentiful they mat in and beneath it. Being entirely surface feeders, should any make their way beyond the cover they can be gently lifted and tucked under the decaying leaves, etc.; but this is a hint that the plant needs a new supply of top dressing. The number of joints laid on or in the soil will vary with the length of the plant, but should not be less than three for this mode of planting, while for long cuttings six or seven joints are needed for a quick start.

If of sufficient length, the free end of the planted vine is hung through a fork of the supporting tree, but it is also advisable to tie it in two or three places to the tree to hinder swinging and chafing. The material used for these ties here is a fiber called _vacoa_[1] which rots in about a year, by which time the plants should have tendril-like roots enough to steady themselves. When once properly planted, the cuttings will need little or no attention for some months, but when the growth becomes vigorous the shoots must be looked after. Such of them as have grown clear of their supports are hitched up and, if long enough, hung through one of the forks. An occasional tie here may also be necessary, but in general a leaf or two of the growing part can be hooked on to some other fixed part of the vine, and in a few days, unless blown loose, the tendrils will have fastened to the leaf, and thus support the plant. Shoots must not be allowed to climb very high among branches of the supporting tree, especially if there be many and close together, or there will be breakages in getting them down. For this purpose, when they get beyond hand reach, a forked stick 6 or 7 feet long is useful. The fork is worked between the tree and climbing vine, and its tendrils in succession are broken by pushing and twisting the stick when they are within the fork. The last two or three tendrils are easily broken or leave the tree without breaking, and care should be taken when the vine is nearly clear to catch the stem of it high up, within the stick’s fork; it can then be lowered gently without fear of breaking.

Some judgment is necessary in selecting the fork of the tree through which each shoot is to hang, a fork whose height fits in with a natural bend of the vine, if it has one, being chosen; otherwise one whose height takes the vine between joints is best, since if bent at a joint the vine is apt to snap, especially so when in vigorous growth, being then full of sap and brittle. In good growing weather--i. e., warm, still, and moist--healthy, well-nourished vanilla vines grow very rapidly, an inch per day being no uncommon rate.

FOOTNOTES:

[1] Obtained from a species of screw pine, _Pandanus utilis_.

PREPARING THE VINES FOR CROPPING.

If the plants have done well they should be ready for such preparation in about eighteen months, more or less, according to the season. Formerly in this colony they were allowed to grow on until a spell of dry weather set in prior to the usual blossoming time. The growing ends were then cut off and all new shoots removed as they showed till flowers began to come or till the season for them was past. When the dry spell proved a long one, this seemed to answer pretty well; and, indeed, under these circumstances flowers would come in any case, whether growth was checked or not. But now it is more usual to stop the growing ends some nine or ten months, in the first instance, before flowering time. In the majority of cases the terminal bud will push, and this new shoot should also be removed when 5 or 6 inches long--not earlier, else the next to the last bud is apt to grow.

After the second checking most vines will shoot far enough back to allow of the shoots being left. These grow on for the next year, and the stopped branches hang down with their lower ends a good foot or more from the ground, being generally from 4 to 6 feet in length, according to the heights of the forks through which they are hung and the positions of the new shoots, though these generally spring just before the last bends of the checked branches, which are to be the cropping parts. The new growths behind these are supposed to drain them of their sap, and thus conduce to flowering. However that may be, these checked hanging branches have certainly more tendency to flower than other parts of the vines. Flowers take some six weeks to develop from the moment they burst through the buds to their time of opening, but this period varies in length with the weather, continuous dryness retarding and moderate showers hastening their development when once started.