Coffee Cultivation.
pp. 40-45 · Read in the full issue
Practical Advice for Pacific Planters.
The following is the text of a pamphlet written a little over a year ago hy Mr. George H. Murray, F.E.S., Director of Agriculture in New Guinea. In all matters relating to tropical agriculture, Mr. Murray is one of the soundest men in the South Seas.
Coffee has never been grown on a commercial scale in New Guinea Terri tory, though plants are to be found on some of the Missions Stations and on one or two plantations where small areas were cultivated experimentally during the German regime. The varieties thus cultivated were Arabian and various types of Liberian coffee, the quality of the former on some of the more elevated Mission Stations being very satisfac tory indeed.
This article is written, therefore, with the view of encouraging planters to en ter upon the cultivation of coffee on a more extensive scale and thus add an important industry to the country, it should be noted that the Commonwealth Government has a preferential tariff ot 3d. per lb. in favour of coffee imported into Australia from the Mandated Ter ritory of New Guinea and Papua, Australia imports nearly 2000 tons per annum, the market there, though not large, is well worthy of consideration, and it should be noted that Australian consumption of coffee is on the increase.
Notwithstanding the large production of coffee in Brazil, the prices obtained for good quality coffee on the European market should pay planters in this Ter ritory. New Guinea is free from the cof fee bean borer (Stephanoderes hampei). a minute Scolytid beetle, which is a very serious pest in Brazil and Java, and planters here, therefore, would have that much in their favour.
Owing to the action of the Department of Agriculture in encouraging planters to engage in new cultures a certain amount of interest has been taken in the cultivation of coffee, one planter in New Ireland having about 15 hectares ready for harvesting.
Several varieties of coffee have been introduced by the Department during the past two and a half years, including Arabian coffee from the famous Blue Mountains of Jamaica. This was planted at the Agricultural Station, Wau, main land of New Guinea, at an altitude of about 3500 feet, and it is now setting a heavy crop of berries. Although there is ample land suitable for this product up to 4500 feet, the absence of roads from the coast at present precludes the pos sibility of growing this type on a large commercial scale. When, however, a road is put through to the Wau suitable for wheeled traffic, or even pack animals, there is no reason why a mountain coffee industry should not be established.
There are several species of coffee and many hybrids or subspecies, varying in the quality of the beans and the climatic and soil conditions necessary for their successful growth. Until recent years the only one extensively cultivated was Arabian coffee in tropical highlands. The well known coffee rust (Hemileia vasta trix) is a fungus which spread from jungle vegetation to the cultivated coffee plants and wiped out the profitable cul tivation of this crop in Ceylon about 1870, but the opinion of many experi enced planters is that the rapid spread of the disease was largely due to grow ing the plants in uncongenial climates at too low an elevation. The conditions of cultivation in Ceylon would appear to have been favourable for the spread of an epidemic and the disease had prob ably been gathering force for years be fore its ravages became noticeable.
A few Arabian coffee trees introduced during the German regime happened to be bearing berries at an elevation of a few hundred feet above sea level, and because of this some planters contem plate growing this variety on a commer cial scale in a locality comparatively few feet above sea level.
The above information is supplied to planters so as to warn them of the risks entailed in carrying out such a scheme.
It is very inadvisable, therefore, to enter upon the cultivation of Arabian on an extensive scale at a lower elevation than 3000 feet, 5000 feet for preference.
There are some districts easily acces sible from the coast, however, suitable for the cultivation of coffee robusta, and it is mainly for that reason that this article has been written.
Coffee robusta, as its specific name indicates, is a vigorous grower, but al though not entirely immune to Hemileia vastatrix it does not suffer unduly from the disease, another point m its favour being that it thrives almost from sea level to an altitude of about 1500 feet.
Discovered originally in the Congo basin
about 30 years ago, it has been intro duced to many countries and with its sub-species is now the type largely grown, except in specially favoured dis tricts where high quality Arabian is still comparatively free from disease. Coffee robusta is also a heavy yielder and comes into bearing in a little more than two years, considerably less than the period ordinarily required for coffee ara bica, which largely compensates for its lower quality.
There is great variation in robusta coffee, many sub-species or varieties re ceiving specific designation according to the districts in which they are found, and on many estates, particularly in Java, managers have special plots of these robusta varieties for observation and experiment. Uganda coffee, one of the robusta types, was introduced into Papua a few years ago and the trees are now bearing heavily, the beans in 1930 having brought £90 per ton in Sydney, though prices have dropped since then like all other primary products. This variety and others have been introduced from the Philippines and other countries, free from the coffee bean borer (Steph anoderes hampei ) and some are now bearing at Keravat.
Robusta grows well on a variety of soils except where too sandy, a deep, rich, clayey loam, preferably of volcanic origin, being most suitable. The pumice soils such as are found in the neigh bourhood of Rabaul, are deficient in pot ash and phosphoric acid and such soils should be avoided. It does not stand drought, requiring a good rainfall, evenly distributed, in fact, soil and climate con ditions are much the same as those re quired by cacao. Long periods of ex posure to hot sun is also injurious to the trees and it is advisable under such con ditions to provide shade by planting le guminous trees or shrubs at suitable distances.
When selecting land for coffee the fol lowing points should be noted: (1) That the soil is deep, clayey, well drained and rich in humus. (2) It should not be exposed to the wind, otherwise the whip-like branches will be damaged. (3) The annual rainfall should be at least 80 inches per annum. (4) The plantation should be near a running stream, as a considerable quan tity of water is required for pulping and washing the coffee.
For planting coffee the land should be thoroughly cleared and it is best to have the stumps removed as many root dis eases will spread from the dead roots to the living plants. If the cost of remov ing all the stumps is greater than the planter can afford, holes 3 feet in diameter should be dug and if a stump happens to be at the spot where the cof fee tree is to be planted, all roots should be removed therefrom. Thorough clear ing, however, is always the most satis factory in the long run.
Nurseries,
A well sheltered site not too far from a good water supply should be selected for a nursery and, after all stumps and roots have been removed, the ground should be reduced to a fine tilth and laid out into beds four feet wide with a path on either side, to ensure good drainage. The beds should be raised about four or five inches above the path. A substantial shelter frame should be erected over the beds high enough for the labourers to walk underneath. The seed should be sown flat side down in rows 10 to 12 inches apart, six inches apart in the rows if perfectly fresh.
As coffee seed soon loses its viability old seed can be sown more closely in a germinating bed and as soon as they
have germinated they can be picked out and planted as in an ordinary nursery.
The seeds should be covered with an inch of soil or slightly deeper if the soil is sandy or in very fine tilth. The seed beds should always be kept moist but not wet, and if the seed is fresh, germ ination will take about four weeks. If seed is not fresh germination will be slower and the percentage much less.
The seed bed should be kept carefully weeded and free from insect pests. It is a good plan to burn a layer of dry brush wood over the seed bed to kill insect pests in the soil and the ashes can be worked into it before the final prepara tion for sowing the seed. The plants will be ready for transplanting into larger nurseries or into their permanent posi
(Continued on page 42.)
tions when they have about four or five pairs of leaves. It is an advantage to have several nurseries distributed at convenient distances from the field where they are to be planted as there is then less risk of the soil being broken away from the roots of the young plants.
Lining Out And Planting.
After the land has been thoroughly cleared it should be lined out at the planting distance desired —10 feet by 10 feet being the usual distance for robusta coffee, the system of lining out whether square or hexagonal, being a matter of opinion, which the planter should decide for himself.
Stout stakes should be driven into the soil to mark the places for the coffee
plants, but shade should be thoroughly established before any planting is done.
Heavy shade is not required but a row of leguminous shrubs like Tephrosia Can dida or one of the Crotolarias should be sown between the lines for coffee, about four months at least before transplant ing the coffee.
The size of the holes for the coffee will depend on the nature of the soil. In deep, friable loam, holes about 18 to 24 inches square and the same in depth will be sufficient but if the soil is heavy it would be better to make the holes three feet square. It is advisable to leave the holes open for a few weeks to allow the soil to become aerated before planting.
If the shade has been planted at the right time, there should be little or no cause to use “bomboms” or other bushes for shading the transplants, but if it is found necessary to use “bomboms,” it will indicate a lack of foresight in the planter.
Planting.
Planting should be done at the begin ning of the wet season, every care being taken that the labourers do not bend the tap root, and to see that the plants are at the same depth that they were in the nursery. The holes should be filled with surface soil pressed well round the plant, and if this operation is done carefully, there should be very few misses.
Below is a sketch plan of coffee plants at 10 feet x 10 feet, permanent shade 20 feet x 20 feet, and a line of temporary shade between the lines of coffee.
Due care should be taken that when the young plants are lifted from the nursery, all broken or injured roots should be snipped off with secateurs.
Shade.
There is a difference of opinion as to the necessity of shade. It is not uncom mon to see one planter removing shade from his coffee, while his neighbour is just as convinced that it is essential.
No shade seems to cause an increased yield per acre, but the longevity of the tree is reduced. On the other hand cof fee grown without shade is more subject to attack from leaf blight or coffee rust.
There can be no doubt that light shade provided by leguminous trees and shrubs is beneficial to the plant, as it is fre quently noticed that plants growing in exposed positions have not the same vigorous leaf growth as in trees growing in similar ground, but provided with light shade. The planter must use his own discretion as to the shade require ments, taking into consideration the al titude and the exposure, the greater the altitude the less shade required and vice verso. It should also be remembered that undue exposure greatly intensifies the exhausting effects of disease. The shad ing must be regulated by lopping back when necessary to prevent the young plants from getting leggy.
The general practice in several coun tries is to plant Leucaena glauca, a small leguminous tree, as permanent shade and one of the Crotalarias or Tephrosia Candida, as temporary shade; the sketch plan above will give a good idea of the system. Other leguminous plants can be used for the purpose, but those named are generally the most satisfactory.
Fruit trees can also be used for shade to a limited extent, the distance apart varying in accordance with the size ot the trees.
Pruning.
The natural growth or robusta coffee is to form a central stem with primary and secondary branches, the latter being usually in pairs. Secondary branches within four or five inches of the mam stem should be removed to allow venti lation and light, for if all are permitted to remain, the growth of fungi will be encouraged. Of the other secondaries, one should be removed from each pair on alternate sides, i.e., one on the left of one pair of secondaries, one on the right of the next pair, and so on.
Except to rub off the young upright shoots on the side of the mam stem, pruning should not be necessary until the trees are about three years old. The trees should be topped to about five teet, cutting back to the brown bark. The top pair of primaries should also be cut oft to prevent the stem from being split by the weight of the branches when they are heavy with fruit.
Cultivation And Cover
Plants.
Coffee, like all other economic plants answers readily to cultivation, and will well repay all attention given to it in this way, due care being taken that the roots are not disturbed. Weeds should not be allowed to get hold of the ground, and every effort should be made to keep out Thurston grass (Paspalum conjuga tum) This grass makes fair grazing for cattle, but it is a positive curse in cul tivated ground, and its presence or ab sence in a coffee plantation is an index of the efficiency or otherwise of the planter. Paspalum dilatatum, the grass which did so much for the dairy indus try in certain parts of Australia, is a de clared noxious plant in orchard districts
o x o
20 feet.
o x o o x o o o o o o o o o o x o o x o o x o o o o o o o o o o x o o x o o x o o o o o
o=Coffee.
x = Leueaena glauca, permanent shade, o o o o . . . . Temporary shade. Tephrosia Candida.
in that country, and its congener, Pas palum conjugatum might well be consid ered such in a coffee plantation in New Guinea.
The cover plants recommended for use on coconut plantations, viz., Galopogonium mucunoides and Centrosema pubescens are un suitable for coffee on account of their tendency to climb. The shade plants re commended will help to keep down weeds, and if the space between the cof fee and lines of shade is planted with Indigofera endecaphylla there will be comparatively little labour required for weeding, provided, of course, that the land is thoroughly clean.
Pests And Diseases.
The coffee growing at the Demonstra tion Plantation, Keravat, has not suf fered to any extent from pests, only a few of minor importance so far having been noted.
There has been a loss of one tree, which died from a form of dieback, not yet identified. It was a solitary case, and there has been no indication of a further outbreak. Preventive measures should be adopted in the event of any trees developing an unhealthy appear ance, such as cultivation of the soil to encourage growth, manuring (green manure or otherwise) and careful regula tion of the shade.
A few instances of attack by stem boring grubs have been recorded, but no mature insects have been obtained, so that they have not yet been identified.
The coffee now being grown in Papua, where the conditions generally are simi lar to those found in this Territory, has not suffered from any serious pest, and we are therefore justified in expecting the same here.
Harvesting And Curing.
The berries should be perfectly ripe at time of picking and they should be put through the pulper the same day. Ro busta coffee is sometimes difficult to pulp and it may be necessary to put it through the pulper a second time.
Fermentation is the next process, the object of which is to remove the muci lage-like substance adhering to the bean.
Vats or boxes similar to those in use for fermenting cacao beans are required. The time necessary for fermentation will de pend on the air temperature, but it should not take longer than 36 hours.
The time when the fermentation has been completed is easily noted by taking a few beans from the middle of the vat and washing them in water. If the slimy matter has all come away from the beans the fermenting process is com plete and they are then ready for wash ing. A plentiful supply of running water is necessary for washing the beans, and when this has been completed they are spread on perforated trays on a raised frame in the sun to dry. Artificial driers are not expensive and if the size of the plantation warrants, the planter would find it to his advantage to invest in one.
Production.
Production in a young plantation is somewhat variable and naturally the yield is heavier where everything in the way of soil and climatic conditions are favourable.
As an instance of what might be ex pected here on good soil, it might be noted that the yield in Papua was 800 lbs. per acre, at the second crop when the trees were about 3½ years old. Con sidering that the labourers were all raw bush natives who had never seen a cof fee tree before, the result was quite sat isfactory. Yields in other parts of the
world have frequently been much greater, but as coffee growing is merely in its infancy in this Territory, it is too soon to state an average yield or what might be expected here.
Provided that the coffee has been planted in good soil and receives good attention the yield should be even better than the Papuan figure mentioned above.
On the rich lands of East Java the yields in the third year was about 540 kg. (1 kg. = 2.3046 lbs.) per hectare, and fourth and fifth years 1400 kgs. and 1830 kgs. respectively per hectare. Four to five kg. of fresh robusta berries make 1 kg. of coffee beans.