Some text was revised from the articles “Date palms”, by D. Abed; “Raffia” and “Sisal”, by E. Arreguin Velez; “Copra”, by A.P. Bulengo; “Kapok”, by U. Egtasaeng; “Coconut cultivation”, by L.V.R. Fernando; “Bananas”, by Y. Ko; “Coir”, by P.V.C. Pinnagoda; and “Oil palms”, by G.O. Sofoluwe from the 3rd edition of this “Encyclopaedia”.
Although archaeological evidence is inconclusive, tropical forest trees transplanted to the village may have been the first domesticated agricultural crops. More than 200 fruit tree species have been identified in the humid tropics. Several of these trees and palms, such as the banana and coconut, are cultivated in smallholdings, cooperatives or plantations. While the date palm is completely domesticated, other species, such as the Brazil nut, are still harvested in the wild. More than 150 varieties of bananas and 2,500 palm species exist around the world, and they provide a broad range of products for human use. Sago palm wood feeds millions of people around the world. The coconut palm is used in more than 1,000 ways and the palmyra palm in more than 800 ways. About 400,000 people depend on the coconut for their entire livelihood. Several trees, fruits and palms of the tropical and semitropical zones of the world are listed in table 1, and table 2 shows selected commercial palms or palm types and their products.
Table 1. Commercial tropical and subtropical trees, fruits and palms
Categories |
Species |
Tropical and semitropical fruits (excluding citrus) |
Figs, banana, jelly palm, loquat, papaya, guava, mango, kiwis, date, cherimoya, white sapota, durian, breadfruit, Surinam cherry, lychee, olive, carambola, carob, chocolate, loquat, avocado, sapodilla, japoticaba, pomegranate, pineapple |
Semitropical citrus fruits |
Orange, grapefruit, lime, lemon, tangerine, tangelos, calamondins, kumquats, citrons |
Tropical nut trees |
Cashew, Brazil, almond, pine, and macadamia nuts |
Oil crops |
Oil palm, olive, coconut |
Insect feed |
Mulberry leaf (silkworm feed), decaying sago palm pith (grub feed) |
Fibre crops |
Kapok, sisal, hemp, coir (coconut husk), raffia palm, piassaba palm, palmyra palm, fishtail palm |
Starch |
Sago palm |
Vanilla bean |
Vanilla orchid |
Groups |
Products |
Uses |
Coconut |
Nut meat Copra (desiccated meat) Nut water Nut shells Coir (husk) Leaves Wood Flower nectar inflorescence |
Food, copra, animal feed Food, oil, oilsoap, candle, cooking oil, margarine, cosmetics, detergent, pai, coconut milk, cream, jam Fuel, charcoal, bowls, scoops, cups Mats, string, potting soil mix, brush, rope, cordage Thatching, weaving Building Palm honey Palm sugar, alcohol, arrack (palm spirits) |
Date |
Fruit Sap |
Dry, sweet and fine dates Date sugar |
African oil |
Fruit (palm pulp oil; similar to olive oil) Seeds (palm kernel oil) |
Cosmetics, margarine, dressing, fuel, lubricants Soap, glycerine |
Palmyra |
Leaves Petioles and leaf sheaths Truck Fruit and seeds Sap, roots |
Paper, shelter, weaving, fans, buckets, caps Carpets, rope, twine, brooms, brushes Timber, sago, cabbage Food, fruit pulp, starch, buttons Sugar, wine, alcohol, vinegar, sura (raw sap drink) Food, diuretic |
Sago (trunk pith of various species) |
Starch Insect feed |
Meals, gruels, puddings, bread, flour Food (grubs feeding on decayed sago pith) |
Cabbage (various species) |
Apical bud (upper trunk) |
Salads, canned palm hearts or palmito |
Raffia |
Leaves |
Plaiting, baskets work, tying material |
Sugar (various species) |
Palm sap |
Palm sugar (gur, jaggery) |
Wax |
Leaves |
Candles, lipsticks, shoe polish, car polish, floor wax |
Rattan cane |
Stems |
Furniture |
Betel nut |
Fruit (nut) |
Stimulant (betel chewing) |
Processes
The agriculture of tropical tree and palm growing includes propagation, cultivation, harvesting and post-harvesting processes.
Propagation of tropical trees and palms can be sexual or asexual. Sexual techniques are needed to produce fruit; pollination is critical. The date palm is doecious, and pollen from the male palm must be dispersed upon the female flowers. Pollination is done either by hand or mechanically. The manual process involves the workers climbing the tree by gripping the truck or using tall ladders to hand pollinate the female trees by placing small male clusters in the center of each female cluster. The mechanical process uses a powerful sprayer to carry the pollen over the female clusters. In addition to use for generating products, sexual techniques are used to produce seed, which is planted and cultivated into new plants. An example of an asexual technique is cutting shoots from mature plants for replanting.
Cultivation can be manual or mechanized. Banana cultivation is typically manual, but in flat terrain, mechanization with large tractors is used. Mechanical shovels may be used to dig drainage ditches in banana fields. Fertilizer is added monthly to bananas, and pesticides are applied with boom sprayers or from the air. The plants are supported with bamboo poles against storm damage. A banana plant bears fruit after two years.
Harvesting relies largely on manual labour, though some machinery is also used. Harvesters cut the banana bunches, called hands, from the tree with a knife attached to a long pole. The bunch is dropped onto a worker’s shoulder and a second worker attaches a nylon cord to the bunch, which is then attached to an overhead cable that moves the bunch to a tractor and trailer for transport. Tapping the coconut inflorescence for the juice entails the taper walking from tree to tree on strands of rope high above the ground. Workers climb to the tree tops to pluck the nuts manually or cut the nuts with a knife attached to long bamboo poles. In the Southwest Pacific area the nuts are allowed to fall naturally; then they are gathered. The date ripens in the fall and two or three crops are gathered, requiring climbing the tree or a ladder to the date clusters. An old system of machete harvesting of fruit bunches has been replaced by the use of a hook and pole. However, the machete is still used in harvesting many crops (e.g., sisal leaves).
Post-harvest operations vary between tree and palm and by the expected product. After harvesting, banana workers—typically women and youth—wash the bananas, wrap them in polyethylene and pack them in corrugated cardboard boxes for shipping. Sisal leaves are dried, bound and transported to the factory. Kapok fruit is field dried, and the resulting brittle fruit is broken open with a hammer or pipe. Kapok fibers are then ginned in the field to remove seeds by shaking or stirring, packed in jute sacks, batted in sacks to soften the fibers and baled. After harvest, dates are hydrated and artificially ripened. They are exposed to hot air (100 to 110 °C) to glaze the skin and semi-pasteurize them and then packaged.
The dried meaty endosperm of the coconut is marketed as copra, and the prepared husk of the coconut is marketed as coir. The fibrous nut husks are stripped off by striking and levering them against spikes firmly fixed into the ground. The nut, stripped of the husk, is split in half with an axe and dried either in the sun, kilns or hot-air dryers. After drying, the meat is separated from the hard woody shell. Copra is used to produce coconut oil, oil extraction residue called copra cake or poonac and desiccated food. The coir is retted (partially rotted) by soaking in water for three to four weeks. Workers remove the retted coir from the pits in waist-deep water and send it for decortication, bleaching and processing.
Hazards and Their Prevention
Hazards in tropical fruit and palm crop production include injuries, natural exposures, pesticide exposures and respiratory and dermatitis problems. Working at high elevations is required for much work with many tropical trees and palms. The popular apple banana grows to 5 m, kapok to 15 m, coconut palms to 20 to 30 m, evergreen date palm to 30 m, and the oil palm, 12 m. Falls represent one of the most serious hazards in tropical tree cultivation, and so do falling objects. Safety harnesses and head protection should be used, and workers should be trained in their use. Using dwarf varieties of the palms may help eliminate the tree falls. Falls from the kapok tree because of branches breaking and minor hand injuries during shell cracking are also hazards.
Workers can be injured during the transport on trucks or tractor-drawn trailers. Workers climbing palms receive cuts and abrasions of the hands due to contact with sharp date palm spines and oil palm fruit as well as spiny sisal leaves. Sprains from falling in ditches and holes are a problem. Severe wounds from the machete may be inflicted. Workers, typically women, who lift packed boxes of bananas are exposed to heavy weights. Tractors should have safety cabs. Workers should be trained in the safe handling of agricultural implements, machinery guarding and safe tractor operation. Puncture-resistant gloves should be worn, and arm protection and hooks should be used in harvesting the oil palm fruit. Mechanization of weeding and cultivation reduces sprains from falls in ditches and holes. Safe and proper work practices should be used, such as proper lifting, getting help when lifting to reduce individual loads and taking breaks.
Natural hazards include snakes—a problem during forest clearing and in newly established plantations—and insects as well as diseases. Health problems include malaria, ancylostomiasis, anaemia and enteric diseases. The retting operation exposes workers to parasites and skin infections. Mosquito control, sanitation and safe drinking water are important.
Pesticide poisoning is a hazard in tropical tree production, and pesticides are used in significant quantities in fruit groves. However, palms have few problems with pests, and those that are a problem are unique to specific parts of the life cycle and thus can be identified for specific control. Integrated pest management and, when applying pesticides, following the manufacturer’s instructions are important protective measures.
Medical evaluations have identified cases of bronchial asthma among date workers probably from pollen exposure. Also reported among date workers are chronic dry eczema and “nail disease” (onychia). Respiratory protection should be provided during the pollination process, and workers should wear hand protection and frequently wash their hands to protect their skin when working with the trees and dates.