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iron, but it still serves its purpose almost to the exclusion of other tools. A mat of bamboos serves as a harrow. What after-tillage is attempted is done with this same wooden plow or with the hoe.

Methods of transportation and marketing are equally primitive. Roads are few or none, produce being mostly carried on the backs of mules or horses and over trails that seem impassible. Little or no attention has been paid to the breeding of improved plants or animals. Live-stock of all kinds is small and poor, owing to lack of care and to long-continued inbreeding. The fruits are all seedlings and the garden vegetables are small and inferior, owing to poor cultivation and lack of care in the selection of seed.

The conditions above described may be taken as representing the present average condition of American tropical agriculture. Signs are not wanting, however, of a rapid change. The better classes of the native populations are highly intelligent, and they begin to feel strongly the need for radical improvements. Keen-minded adventurous foreigners of all nations are flocking to these countries in constantly increasing numbers and are bringing with them improved implements, seeds, live-stock, and a knowledge of the best modern methods. Already with some crops and in a few regions tropical agriculture is taking an advanced position. The Hawaiian sugar-planters, with their skilful use of modern implements, fertilizers and irrigation, hold the world's record for sugar production. The tobacco-growers of western Cuba, aided by the favorable soil and climate, have for years produced the finest tobacco that is known. In Jamaica there are herds of grass-fed Hereford cattle equal to those fattened in the Kansas cornfields.

The radical changes in method that are necessary before tropical agriculture can take its true place in the world's economy are thus seen to be wellbegun, at least in favored localities. What these changes are will be considered more in detail under three headings.

A. The wider use of improved implements and machinery.

Hand labor is slow and expensive. The use of implements cheapens production. These are facts that are not yet fully realized in the tropics. The sugar-planters of Jamaica and Porto Rico still open holes with the hoe for planting sugar-cane instead of using a sulky lister for opening a deep furrow. In Cuba the lister is now in general use, but the cane is covered by the hoe, while a disk cultivator would do the work as well, thus saving the labor of twenty men. The immense cane-fields of the tropics are still mainly cleared of grass and weeds by the hoe. This is ruinously expensive. Cultivators drawn by animals would do the work much more cheaply and much better, since, besides destroying the weeds, they aerate and pulverize the soil. The disadvantage of excessive tillage under tropical conditions has been pointed out in a previous paragraph. In the level cane-fields, however, tillage becomes a necessity if one is to secure maximum

crops, except from virgin lands; yet tillage worthy of the name scarcely exists. Cane-planters need to study and to copy the methods of the corn-growers of the Middle West. The two plants are closely related, and their needs are much the same. The rice crop of the tropics is all planted and harvested by hand. Therefore, it cannot compete with that of Louisiana and Texas, which is planted with the drill and harvested with the self-binder. Cheapening production by the adoption of better methods and implements must be counted today as the greatest need of tropical agriculture.

B. Soil-improvement.

Little attention has been given in the tropical countries of this hemisphere to the fundamentally important questions connected with maintaining and increasing the fertility of the soil. Nature's bounty has been drawn on lavishly, while the only restorative measure adopted has been the turning back of impoverished lands to be built up by slow natural processes. This system is wasteful and can be tolerated only when land is cheap and population sparse. Since live-stock is not housed on the farms, stable-manure can be obtained only in the neighborhood of the towns. It can never be relied on here as the basis for soil-improvement. Greenmanuring supplemented by commercial fertilizers must largely take its place, yet green-manuring is but little understood, or practiced, while commercial fertilizers are as yet used only for a few crops in restricted localities. The flora of the tropics is rich in species of leguminous plants, some of which are undoubtedly adapted to each of the manifold conditions of soil and climate that are presented. Many of

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Fig. 110. To show that sugar-cane may profit by fertilizing in the tropics. The part on the right has been fertilized with tankageand potash at rate of 500 kilos, per hectare; part on left unfertilized. Cuba.

are exceedingly important points in the tropics, where fermentation and nitrification go on so rapidly, and where the soil is exposed to the wasteful action of such heavy rains. On the rich, heavy soils, of which there are so many, it is possible by this means alone to keep up the fertility for a great many years. On the lighter soils, however, the phosphoric acid and potash are soon exhausted, and even on the best lands, if they are subjected to continued cropping, a time will come when the available supply of these elements will begin to fail. When such a deficiency occurs, the only recourse is to the use of commercial fertilizers. Such a condition has now been reached on many of the older sugar lands of the West Indies, and the intelligent use of fertilizers will unquestionably be profitable here, as it has already been proved to be in the Hawaiian islands. In the light soils of the Vuelta Abajo of Cuba, the famous tobacco crop is practically all grown by the use of commercial fertilizers. Fig. 110 indicates results that can be secured with sugar-cane.

Many of the low lands of the tropics require drainage. At present, drainage is universally effected by open ditching. These ditches, though comparatively cheap as to first cost, are very expensive to maintain; they waste much land, transport weed seeds, and greatly impede cultivation and the transportation of crops. Ultimately, drainage will doubtless be accomplished by tiling, as is now the case in all regions where the best agricultural practices prevail. A useful beginning in this direction has recently been made by the Porto Rico Experiment Station.

In the hill-lands drainage is seldom needed, but here the problem is to prevent loss from washing and gullying. When crops requiring tillage are to be grown on these lands, great advantage would unquestionably come from adopting the system of terracing so widely used by the cotton-planters in

the hill-lands of the southern United States. In planting the more permanent crops, such as coffee, cacao, fruits, and the like, which are usually grown under forest-like conditions, it will be advantageous to locate the rows on contour lines, circling the hill, as it is often called, not only to prevent washing but also to facilitate the gathering of the crop; since, in following such a row, the harvesters will always be walking and carrying their burdens on a level.

Crop rotation and the greater diversification of crops are questions intimately associated with preserving the fertility of the soil. In most tropical countries, the tendency is to depend too much on a few great staples, such as sugar, tobacco or coffee. This is unfortunate from an economic as well as from an agricultural standpoint. The continued growing of the same crop on the same land year after year tends to the early depletion of fertility, while a carefully devised rotation of crops does much to preserve it. Rotation becomes possible only when there is diversification. Again, continuous cropping tends to increase the trouble from insects and diseases. An abundant and continuous food supply necessarily aids in their multiplication, while a proper rotation of crops is often one of the best means of combating pests, since it can be so planned as to cut off the food supply of those which threaten to become troublesome. In any wellconsidered plan for rotation, some leguminous plant for soil-improvement should be frequently introduced, and this is particularly necessary in the tropics. Here, however, advantage may often be taken of the long growing season by planting a soil-improving crop during that part of the year when the fields are not occupied by the principal money crop, thus providing for what is practically a short rotation without losing the use of the land for the principal crop. This is notably the case with tobacco, which occupies the land for only three or four months. The growing of cowpeas or velvet-beans on tobacco lands during the off season will do much toward decreasing the size of the fertilizer bills.

C. Selection and breeding.

One of the most notable defects that a visitor notices in a tropical market is the poor average quality of the fruits and vegetables. The fruits are always seedlings and consequently lack uniformity in quality, and the vegetables, for the most part, are poor degenerates, showing absolute lack of attention to the principles of plant-breeding and seed selection. With the staple crops it is much the same. Even in the famous Cuban tobacco-fields no attempt has been made at seed selection, and plants of the most varied types are found growing side by side. The seeds for the next planting are saved indiscriminately from the weak suckers that spring up from near the roots after the harvesting of the crop. The mere recording of such facts at once indicates the vast possibilities that await the intelligent plant-breeder in the tropics. Here Nature is in her most bounteous mood, and there is every reason to expect that the hybridizer and breeder will be able to produce a richer array of variations from which to make his selections than is possible nnder the more rigorous conditions of cold climates. The very fact that all the native fruits are seedlings gives the trained horticulturist a wonderful opportunity for selection, and makes it possible for him quickly to obtain great results by the propagation of the many valuable kinds that already exist, but which are now so completely neglected and overlooked.

With domestic animals the case is much the same. Chickens, pigs, cattle and horses are all, as a rule, small in size and poor in quality. Perhaps an exception should be made in the case of cattle, for in many countries, thanks to rich natural pasturage, these have retained sufficient size; but they are coarse in build and slow in maturing, and entirely lack the fine qualities of the improved breeds. The opinion prevails very widely that there is an inevitable tendency for domestic animals of

all kinds to deteriorate when taken to the tropics, and that in a few generations the descendants of even the best-bred animals will be no better than the native stock. Carefully conducted experiments are lacking by which to prove whether or not there is any real foundation for this belief. It is certain, however, that most of the existing deterioration is due not to climatic causes, but to the absolute neglect of all hygienic conditions, lack of proper food and shelter, and to careless inbreeding or promiscuous crossing with inferior strains. Many tropical countries are already great producers of cattle. Experience in Jamaica, and to a less extent in Cuba, demonstrates that it is as possible to produce good cattle as poor cattle. Serious diseases seem to be no more prevalent than in the North. With cheapness of production, made possible by the wonderful pasture grasses and forage plants, it seems probable that the center of meat production, as well as of population, will soon swing markedly southward.

AGRICULTURE IN THE AMERICAN TROPICS IN ITS RELATION TO

PLANT INTRODUCTION

By DAVID FAIRCHILD and O. W. BARRETT

Tropical agriculture is radically different from the agriculture of the temperate zone. Farming as it is understood in this country does not exist along the equator, for animal husbandry is almost unknown there. Cattle and hogs, it is true, are raised in small numbers for family use, but dairying and stock-raising for the slaughter-house are industries of small importance when compared with the plantations of the great staple crops grown for export.

There are no great markets for farm produce in the tropics. The aim of tropical agriculture has been to produce something that is wanted by the great cities of the North, and the whole history of the growth and development of certain tropical colonies has been dependent on the demand for a single tropical product in the northern centers of civilization. Cane-sugar was a luxury to supply which the vast cane-fields of the oriental and western tropics were developed; spices were worth their weight in gold in the days of Ferdinand and Isabella, and the Portuguese sailed around Africa in search of the spice islands of the Moluccas. The introduction of the coffee-drinking fashion into Europe is responsible for the beginning of vast coffee plantations that now cover thousands of square miles in Brazil and the islands of the East and West Indies. The mountains of south India, Ceylon, Java, China and Japan are now covered with tea-plants, the infusion of whose leaves was an unknown drink in Europe three lifetimes ago. When Markham, at the risk of his life, got the Cinchona plants from the Peruvians, it was a paying industry that he transplanted, an industry created by the discovery of the antipyretic value of quinine.

As its past history has been closely bound to the wants of the great buying markets of temperate zones, so the future of tropical agriculture lies in

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Americans are interested not only in tropical American territory, but are pushing their inquisitive way into the great regions of Mexico, Central and South America, and scattering themselves throughout the torrid zone; so that brief forecasts of new crop possibilities may be of interest to them.

Fruit industries.

Fruit-growing in the American tropics, though horticultural in character, is rapidly becoming one of its greatest agricultural industries. The new fruits that have come into popularity within the last fifteen years have been nearly all of tropical or subtropical species, notwithstanding the fact that fruit-culture in the tropics is almost wholly undeveloped. The possibilities in the way of entirely new northern fruits are almost exhausted, while the wealth of delicious fruits of the torrid zone has barely been explored.

There are no other tropical territories so favorably situated as the West Indies and Hawaii for the encouragement of tropical fruit-culture, and it seems incredible that industries which offer so much have been so evidently overlooked by those who should encourage them. The example taught by the growth of banana-culture in Jamaica and Central America should be taken seriously, for some of the most delicious fruits in the world are waiting to be introduced into the western tropics and grown for the American market.

The mangosteen (Fig. Ill) should head the list of new fruit possibilities for the western tropics. Known in the Orient as the "queen of tropical fruits," it is, without question, the most deliciously flavored fruit of that marvelously rich fruit region, the Malay Archipelago. When once known, Americans would pay fancy prices for it; and it is so delicate that it never cloys and a man can eat dozens in a day. Yet with all these possibilities, combined with good shipping qualities, the mangosteen still remains practically unknown in the West

Indies, two trees in Jamaica and two in the Trinidad Botanic Gardens being the only ones on record. The genus to which this practically uncultivated fruit belongs has over sixty-five species, and counts fifteen edible-fruited forms among the number, one of these being as large as a Rocky Ford melon. Hitherto, the weak root-system of the mangosteen has stood in the way of its general cultivation, but no careful

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Hard-shelled avocado (Pertta gratittima).

Fie. 112. Mulcoba mango. The first of the East Indian vaiieties planted in America.

attempts have been made to graft it on other stocks. The trained horticulturist, by breeding and grafting, has in this family of Guttiferm a field for his activities more remarkable and promising than that of the Japanese plums so well worked out by American horticulturists.

A fruit that will be planted in considerable areas in the tropics sooner than the mangosteen is the East Indian mango (Fig. 112). The East Indian varieties of this fruit are not to be confused with those now growing in the American tropics, and even already to be had on our large markets. The latter are such rank-flavored seedlings, with disagreeable turpentine taste, that it will be difficult to convince those who have tried only the West Indian mangos that those of the East Indies are so different as to deserve rank as a new fruit. The eastern mango is one of the richest flavored, most enticing fruits in the world, and combines, in its custard-like pulp, the fragrance of the apricot and the pineapple. A wonderfully prolific cropper, long-lived, quick in growth and flourishing in poor soils that are not over-wet, the mango has possibilities for the western tropical horticulturist possessing shipping facilities, which deserve his most serious and immediate study. Already in Florida, Hawaii and Porto Rico, the Office of Seed and Plant Introduction of the United States Department of Agriculture is making a special point of establishing the best varieties from India, the Malay Archipelago, the Philippines, the East Coast of Africa and the South Sea Islands, and it will not be long before these delicious mangos are on our great markets, where they are sure to attract attention.

It is a mystery why the Chinese leitchee, or litchi (Nephdium. Litchi), and its Javanese relatives, the ramboetan and capoelasan, have never found their way into the tropics of the Occident, when one considers that they are among the showiest of all table fruits and are more delicate in flavor than the richest of plums. In southern China these are the most highly prized of all fruits, and there is one variety that is said to be reserved exclusively for the highest officials. In Honolulu, the Afong leitchee tree, growing in the yard of a former Chinese resident of the place, produced in 1904 about two thousand fruits, which sold in the local markets for three cents each. In this group of fruits, of which there are a dozen or more varieties, lies an industry that will one day cover hundreds, perhaps thousands, of acres of tropical hillsides with orchards.

Throughout the wonderfully fertile island of Java, the natives sell, in immense quantities, braided bunches of a delicate fruit called the doekoe (Lantium domestieum, family Meliacem), which, even as a botanic garden plant, seems quite unknown to the American tropics. The possibilities of this plant, the straw-brown fruits of which are keenly relished by the jaded appetites of the Dutch colonists, are still quite unexplored.

already borne a few velvety and exceedingly fragrant guava-like fruits in the gardens of that region, but its prospects and those of its three or more nearly related species or varieties are among the unsolved problems of the tropics.

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Fie. 115. The edible roots of the yautia.

One of the latest arrivals in the northern markets is the avocado (Persea gratissima). Its increase in public favor as a salad may be judged by the fact that in the Bellevne-Stratford Hotel in Philadelphia nearly two hundred fruits a day are now used, while two years ago not a dozen were served. A variety from Central America, discovered by M. G. N. Collins, and having a tough, shelllike rind (Fig. 113), should show better shipping qualities than those heretofore grown in Florida, Hawaii and Porto Rico. The Florida varieties are already being given special names, as are the mango and orange; and, since these are being propagated by budding, the unreliable seedlings are now used only for stocks. Some twenty varieties are now recognized when a few years ago there were believed to be only two, and among them is a "seedless" sort. Two other related species of the genus Persea are also being tried as stocks. Persea is a genus of the Lauracea. The fruit of P. gratissima is variously known as avocado, avocado pear, alligator pear, aguacate.

Were these few examples not enough to give some hint of the untouched possibilities of fruit introduction in the tropics, the merits of the eugenia, anona, sapodilla, passion fruit, and the amatungula (a Carissa, family Apocynaeece) with very many others, might be presented.

Tropical vegetables.

The yautias, or taniers, and the taros, are among the most promising of the many root-crops of the tropics to the modern agriculturist (Figs. 114, 115). Until recently, both were confused in nearly every account of them, but it is now generally known that all true taniers belong to the genus Xanthosoma, while the taros all come under the genus Coheasia. These crops have been under cultivation longer, it is believed, than any other, and are probably the only ones that never produce true seeds. For many years, varieties have been grown on a small scale in the southern states, but the recent appreciative interest in taro flour will encourage the extensive cultivation of the sixty or seventy-five varieties of these very inter

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