Chapter 41
CULTIVATION OF THE COFFEE PLANT
_The early days of coffee culture in Abyssinia and Arabia--Coffee cultivation in general--Soil, climate, rainfall, alt.i.tude, propagation, preparing the plantation, shade and wind breaks, fertilizing, pruning, catch crops, pests, and diseases--How coffee is grown around the world--Cultivation in all the princ.i.p.al producing countries_
For the beginnings of coffee culture we must go back to the Arabian colony of Harar in Abyssinia, for here it was, about the fifteenth century, that the Arabs, having found the plant growing wild in the Abyssinian highlands, first gave it intensive cultivation. The complete story of the early cultivation of coffee in the old and new worlds is told in chapter II, which deals with the history of the propagation of the coffee plant.
La Roque[314] was the first to tell how the plant was cultivated and the berries prepared for market in Arabia, where it was brought from Abyssinia.
The Arabs raised it from seed grown in nurseries, transplanting it to plantations laid out in the foot-hills of the mountains, to which they conducted the mountain streams by ingeniously constructed small channels to water the roots. They built trenches three feet wide and five feet deep, lining them with pebbles to cause the water to sink deep into the earth with which the trenches were filled, to preserve the moisture from too rapid evaporation. These were so constructed that the water could be turned off into other channels when the fruit began to ripen. In plantations exposed to the south, a kind of poplar tree was planted along the trenches to supply needful shade.
La Roque noted that the coffee trees in Yemen were planted in lines, like the apple trees in Normandy; and that when they were much exposed to the sun, the shade poplars were regularly introduced between the rows.
Such cultivation as the plant received in early Abyssinia and Arabia was crude and primitive at best. Throughout the intervening centuries, there has been little improvement in Yemen; but modern cultural methods obtain in the Harar district in Abyssinia.
Like the Arabs in Yemen, the Harari cultivated in small gardens, employing the same ingenious system of irrigation from mountain springs to water the roots of the plants at least once a week during the dry season. In Yemen and in Abyssinia the ripened berries were sun-dried on beaten-earth barbecues.
The European planters who carried the cultivation of the bean to the Far East and to America followed the best Arabian practise, changing, and sometimes improving it, in order to adapt it to local conditions.
_Coffee Cultivation in General_
Today the commercial growers of coffee on a large scale practise intensive cultivation methods, giving the same care to preparing their plantations and maintaining their trees as do other growers of grains and fruits. As in the more advanced methods of arboriculture, every effort is made to obtain the maximum production of quality coffee consistent with the smallest outlay of money and labor. Experimental stations in various parts of the world are constantly working to improve methods and products, and to develop types that will resist disease and adverse climatic conditions.
While cultivation methods in the different producing countries vary in detail of practise, the principles are unchanging. Where methods do differ, it is owing princ.i.p.ally to local economic conditions, such as the supply and cost of labor, machinery, fertilizers, and similar essential factors.
[Ill.u.s.tration: IMPLEMENTS USED IN EARLY ARABIAN COFFEE CULTURE
1, Plow. 2 and 3, Mattocks. 4, Hatchet and sickle. Top, Seeder Implement]
SOIL. Rocky ground that pulverizes easily--and, if possible, of volcanic origin--is best for coffee; also, soil rich in decomposed mold. In Brazil the best soil is known as _terra roxa_, a topsoil of red clay three or four feet thick with a gravel subsoil.
CLIMATE. The natural habitat of the coffee tree (all species) is tropical Africa, where the climate is hot and humid, and the soil rich and moist, yet sufficiently friable to furnish well drained seed beds.
These conditions must be approximated when the tree is grown in other countries. Because the trees and fruit generally can not withstand frost, they are restricted to regions where the mean annual temperature is about 70 F., with an average minimum about 55, and an average maximum of about 80. Where grown in regions subject to more or less frost, as in the northernmost parts of Brazil's coffee-producing district, which lie almost within the south temperate zone, the coffee trees are sometimes frosted, as was the case in 1918, when about forty percent of the So Paulo crop and trees suffered.
Generally speaking, the most suitable climate for coffee is a temperate one within the tropics; however, it has been successfully cultivated between lat.i.tudes 28 north and 38 south.
RAINFALL. Although able to grow satisfactorily only on well drained land, the coffee tree requires an abundance of water, about seventy inches of rainfall annually, and must have it supplied evenly throughout the year. Prolonged droughts are fatal; while, on the other hand, too great a supply of water tends to develop the wood of the tree at the expense of the flowers and fruit, especially in low-lying regions.
ALt.i.tUDE. Coffee is found growing in all alt.i.tudes, from sea-level up to the frost-line, which is about
Carvalho says that the coffee plant needs sun, but that a few hours daily exposure is sufficient. Hilly ground has the advantage of offering the choice of a suitable exposure, as the sun s.h.i.+nes on it for only a part of the day. Whether it is the early morning or the afternoon sun that enables the plant to attain its optimum conditions is a question of locality.
[Ill.u.s.tration: CROSS SECTION OF MOUNTAIN SLOPE IN YEMEN, ARABIA, SHOWING COFFEE TERRACES
These miniature plantations are found chiefly along the caravan route between Hodeida and Sanaa]
[Ill.u.s.tration: CLEARING VIRGIN FOREST FOR A COFFEE ESTATE IN MEXICO]
[Ill.u.s.tration: COFFEE NURSERY UNDER A BAMBOO ROOF IN COLOMBIA]
[Ill.u.s.tration: THE FIRST STEPS IN COFFEE GROWING]
In Mexico, Romero tells us, the highlands of Soconusco have the advantage that the sun does not s.h.i.+ne on the trees during the whole of the day. On the higher slopes of the Cordilleras--from 2,500 feet above sea-level--clouds prevail during the summer season, when the sun is hottest, and are frequently present in the other seasons, after ten o'clock in the morning. These keep the trees from being exposed to the heat of the sun during the whole of the day. Perhaps to this circ.u.mstance is due the superior excellence of certain coffees grown in Mexico, Colombia, and Sumatra at an alt.i.tude of 3,000 feet to 4,000 feet above sea-level.
Richard Spruce, the botanist, in his notes on South America, as quoted by Alfred Russel Wallace,[315] refers to "a zone of the equatorial Andes ranging between 4,000 and 6,000 feet alt.i.tude, where the best flavored coffee is grown."
PROPAGATION. Coffee trees are grown most generally from seeds selected from trees of known productivity and longevity; although in some parts of the world propagation is done from shoots or cuttings. The seed method is most general, however, the seeds being either propagated in nursery beds, or planted at once in the spot where the mature tree is to stand. In the latter case--called planting at stake--four or five seeds are planted, much as corn is sown; and after germination, all but the strongest plant are removed.
Where the nursery method is followed, the choicest land of the plantation is chosen for its site; and the seeds are planted in forcing beds, sometimes called cold-frames. When the plants are to be transplanted direct to the plantation, the seeds are generally sown six inches apart and in rows separated by the same distance, and are covered with only a slight sprinkling of earth. When the plants are to be transferred from the first bed to another, and then to the plantation, the seeds are sown more thickly; and the plants are "p.r.i.c.ked" out as needed, and set out in another forcing bed.
During the six to seven weeks required for the coffee seed to germinate, the soil must be kept moist and shaded and thoroughly weeded. If the trees are to be grown without shade, the young plants are gradually exposed to the sun, to harden them, before they begin their existence in the plantation proper.
[Ill.u.s.tration: COFFEE TREE NURSERY, PANAJABAL, POCHUTA, GUATEMALA]
[Ill.u.s.tration: DRYING GROUNDS AND FACTORY IN THE PREANGER REGENCY]
[Ill.u.s.tration: NATIVE TRANSPORT, FIELD TO FACTORY, AT DRAMAGA, NEAR BUITENZORG]
[Ill.u.s.tration: COFFEE SCENES IN JAVA, NETHERLANDS EAST INDIES]
Considerable experimental work has been done in renewing trees by grafting, notably in Java; but practically all commercial planters follow the seed method.
[Ill.u.s.tration: COFFEE GROWING UNDER SHADE, PORTO RICO]
PREPARING THE PLANTATION. Before transplanting time has come, the plantation itself has been made ready to receive the young plants.
Coffee plantations are generally laid out on heavily wooded and sloping lands, most often in forests on mountainsides and plateaus, where there is an abundance of water, of which large quant.i.ties are used in cultivating the trees and in preparing the coffee beans for market. The soil most suitable is friable, sandy, or even gravelly, with an abundance of rocks to keep the soil comparatively cool and well drained, as well as to supply a source of food by action of the weather. The ideal soil is one that contains a large proportion of pota.s.sium and phosphoric acid; and for that reason, the general practise is to burn off the foliage and trees covering the land and to use the ashes as fertilizer.
In preparing the soil for the new plantation under the intensive cultivation method, the surface of the land is lightly plowed, and then followed up with thorough cultivation. When transplanting time comes, which is when the plant is about a year old, and stands from twelve to eighteen inches high with its first pairs of primary branches, the plants are set out in shallow holes at regular intervals of from eight to twelve, or even fourteen, feet apart. This gives room for the root system to develop, provides s.p.a.ce for sunlight to reach each tree, and makes for convenience in cultivating and harvesting. _Liberica_ and _robusta_ type trees require more room than _arabica._ When set twelve feet apart, which is the general practise, with the same distance maintained between rows, there are approximately four hundred and fifty trees to the acre. In the triangle, or hexagon, system the trees are planted in the form of an equilateral triangle, each tree being the same distance (usually eight or nine feet) from its six nearest neighbors.
This system permits of 600 to 800 trees per acre.
SHADE AND WIND BREAKS. Strong, chilly winds and intensely hot sunlight are foes of coffee trees, especially of the _arabica_ variety.
Accordingly, in most countries it is customary to protect the plantation with wind-breaks consisting of rugged trees, and to shade the coffee by growing trees of other kinds between the rows. The shade trees serve also to check soil erosion; and in the case of the leguminous kinds, to furnish nutriment to the soil. Coffee does best in shade such as is afforded by the silk oak (_Grevillea robusta_). In _Shade in Coffee Culture_ (_Bulletin_ 25, 1901, division of botany, United States Department of Agriculture), O.F. Cook goes extensively into this subject.
The methods employed in the care of a coffee plantation do not differ materially from those followed by advanced orchardists in the colder fruit-belts of the world. After the young plants have gained their start, they are cultivated frequently, princ.i.p.ally to keep out the weeds, to destroy pests, and to aerate the earth. The implements used range from crude hand-plows to horse-drawn cultivators.
FERTILIZING. Comparatively little fertilizing is done on plantations established on virgin soil until the trees begin to bear, which occurs when they are about three years of age. Because the coffee tree takes potash, nitrogen, and phosphoric acid from the soil, the scheme of fertilizing is to restore these elements. The materials used to replace the soil-const.i.tuents consist of stable manure, leguminous plants, coffee-tree prunings, leaves, certain weeds, oil cake, bone and fish meal, guano, wood ashes, coffee pulp and parchment, and such chemical fertilizers as superphosphate of lime, basic slag, sulphate of ammonia, nitrate of lime, sulphate of potash, nitrate of potash, and similar materials.
The relative values of these fertilizers depend largely upon local climate and soil conditions, the supply, the cost, and other like factors. The chemical fertilizers are coming into increasing use in the larger and more economically advanced producing countries. Brazil, particularly, is showing in late years a tendency toward their adoption to make up for the dwindling supply of the so-called natural manures. As the coffee tree grows older, it requires a larger supply of fertilizer.
[Ill.u.s.tration: THE FAMOUS BOEKIT GOMPONG ESTATE, NEAR PADANG, ON SUMATRA'S WEST COAST
Showing the healthy, regular appearance of well-cultivated coffee bushes, twenty-six years old. Also note the line of feathery bamboo wind-breaks]
PRUNING. On the larger plantations, pruning is an important part of the cultivation processes. If left to their own devices, coffee trees sometimes grow as high as forty feet, the strength being absorbed by the wood, with a consequent scanty production of fruit. To prevent this undesirable result, and to facilitate picking, the trees on the more modern plantations are pruned down to heights ranging from six to twelve feet. Except for pruning the roots when transplanting, the tree is permitted to grow until after producing its first full crop before any cutting takes place. Then, the branches are severely cut back; and thereafter, pruning is carried on annually. Topping and pruning begin between the first and the second years.
[Ill.u.s.tration: COFFEE ESTATE IN ANTIOQUIA, COLOMBIA, SHOWING WIND-BREAKS]
Coffee trees as a rule produce full crops from the sixth to the fifteenth year, although some trees have given a paying crop until twenty or thirty years old. Ordinarily the trees bear from one-half pound to eight pounds of coffee annually, although there are accounts of twelve pounds being obtained per tree. Production is mostly governed by the cultivation given the tree, and by climate, soil, and location. When too old to bear profitable yields, the trees on commercial plantations are cut down to the level of the ground; and are renewed by permitting only the strongest sprout springing out of the stump to mature.