Una presentación del cacao

Taza utilizada por los Aztecas durante las ceremonias rituales con Cacahoatl

El cacao era cultivado en América por los Mayas mucho antes de la llegada de los europeos. Fue con su nombre nativo Maya que Hernandez dió en 1630 la primera descripción botanica del árbol (cacahoquahuitl), de sus frutos (cacahoacentli) y de sus semillas(cacahoatl). Durante el tiempo de los aztecas el cacao era urilizado como una bebida. Vinos y bebidas eran hechas de la pulpa blanca que existe alrededor de la semilla del fruto del cacao Las semillas eran utilizadas para hacer una bebida parecida con el chocolate. Las bebidas seculares de los Mayas y de los Aztecas eran hechas con semillas tostadas, con un agente espumoso, mais tostado y agua. También se utilizaba vanilla y chilli como ingrediente en las bebidas. Las semillas de cacao eran utlizadas también como moneda y como un tributo de las poblaciones controladas por los Aztecas. La capa aceitosa que flotaba en la bebida de chocolate era usada para proteger la piel del sol. Para los Aztecas el cacao tenía importantes significados religiosos. Se creía que el cacao tenía un origen divino: el árbol de cacao era un puente entre el cielo y la tierra. Se realizaban sacrificios humanos santificandolos con chocolate para propiciar a Dios o al Sol. Las semillas eran dadas a los asistentes de los sacerdotes para las cerimonias de pasaje de edad de los niños. Durante el matrimonio la pareja bebía una copa simbolica de chocolate y se intercambiaban semillas de cacao. Los Aztecas creían que beber chocolate daba a los mortales algo de la sabiduría de Quetzalcoatl (Dios de la enseñanza y del viento). Hoy en día el cacao ha perdido su aura mistica en centroamérica. El cacao es cultivado como un producto de mercado en América Latina. En 1996/97 la producción de cacao en esta región era de alrededor de 461.000 toneladas de semillas de cacao. El cacao se consume bajo la forma de bebidas hechas de pulpa de cacao, de polvo de cacao y de chocolate. En 1995/96 el consumo de cacao per capita era de 0.256kg en Ecuador, 0.322kg en Venezuela, 0.752kg en Brasil, 1.23kg en Colombia y 1.014kg en Argentina. El cacao es también utilizado en la industria de los comesticos. Cocoa is also still used in the cosmetics industry. El nombre de cacao, originario del Maya, fue utilizado por la primera vez en la literatura botanica en 1605 por Charles de L'Ecluse.

En 1700, Tournefort introduce al cacao como un genero. Sin embargo, Linneo en 1737 adoptó el nombre de Theobroma (bebida de los dioses) para el genero.

Las dos sub-especies son infertiles: los hibridos son llamados trinitarios (de la Isla de Trinidad). Combina el vigor del forastero con el buen aroma del criollo.

Native to South America, probably on the equatorial slopes of the Andes; now cultivated pantropically, especially in West Africa.

Ranging from Subtropical Dry to Wet through Tropical Very Dry to Wet Forest Life Zones, cacao is reported to tolerate annual precipitation of 4.8 to 42.9 dm (mean of 109 cases = 16.3), annual temperature of 18.0 to 28.5°C (mean of 108 cases = 25.3), and pH of 4.3 to 8.7 (mean of 43 cases = 6.4) (Duke, 1978). Grown from 20°N to 20°S with the bulk between 10°N and 10°S, usually below 300 m, but in sheltered valleys of Colombia at 900 m. Requires uniformly high temperatures with recommended mean of 26.6°C. Trees are wind-intolerant and therefore are often planted on hillsides for wind protection and good drainage. Being drought-intolerant, cacao thrives in climates with high humidity and rainfall. Plants are shade-tolerant, and thrive in rich, organic, well-drained, moist, deep soils. Shallow laterite soils are said not to be suitable. Maximum temperature of 33.5°C and minimum 13°C, with diurnal temperature variation between 33.5 and 18°C are suggested (Reed, 1976).

Small tree usually 4–8 m tall, rarely up to 20 m; at 1–1.5 m the terminal bud breaks into 3–5 meristems to give several lateral upright shoots; primary branching by successive whorls of normally spreading branches; young branchlets terete, grayish green or brownish, densely or sparsely pubescent, with simple or furcate hairs 0.1–0.3 mm long, later glabrate, more or less striate; stipules subulate, very acute, 5–14 mm long, 0.5–1.5 mm broad at base, pubescent, deciduous; leaves large, coriaceous or chartaceous, alternate, distichous on normal branches, green; petiole pubescent or tomentose, with simple, rather dense, spreading hairs, thickened pulvinate at ends; blades 12–60 cm long, 4–20 cm broad, elliptic to obovate-oblong, entire, glabrous; inflorescence on trunk and branches, usually borne on small tubercles in short cymose branchlets, peduncles 1–3 mm long, stellate-pubescent; bracts ovate or ovate-oblong, pubescent; bracteoles ovate-oblong, acute or subacute, 0.5–1.2 mm long, pubescent, deciduous; pedicels capillary, rigid, pale green, whitish or reddish, 5–15 mm long, with stellate or furcate hairs and sparce many-celled, glandular, capitate trichomes; sepals lanceolate or oblong-lanceolate, acute, white, greenish-white, pale violaceous or reddish, faintly 3-veined, united at base, 5–8 mm long, 1.5–2 mm broad, with hairs and trichomes; petals contorted in aestivation, thick-membranous, hood 3–4 mm long, 0.5–2 mm wide, obovate, rounded at apex, white, 3-veined, lamina pale yellowish, 1.5–2.5 mm long, 1.5–2 mm broad, obovate, attenuate at apex; staminodes 4–6 mm long, narrowly subulate, red or purplish, minutely papillose-pilose, ciliate, with slender, simple hairs; stamens diantheriferous, with anthers about 0.4 mm long; ovary oblong-ovoid, superior, with 5 carpels; fruits usually considered drupes but referred to as pods, indehiscent, variable in size and shape, 10–32 cm long, spherical to cylindrical, pointed or blunt, smooth or warty, with or without 5 or 10 furrows; pods white, green or red, ripening to green, yellow, red or purple; seeds 20–60 per pod, arranged in 5 rows, variable in size, 2–4 cm long, 1.2–2 cm broad, ovoid or elliptic; cotyledons white to deep purple, convoluted, large. Seeds/kg 625–1125. Roots mostly a mass of surface-feeding roots, with taproot penetrating to 2 m in friable soil, less deeply where compacted (Reed, 1976).

Propagation may be by cuttings, buddings or graftings, but seeding is cheaper. Seeds germinate at maturity, and are viable only a short time. They may be stored 10–13 weeks if moisture content is kept at 50%. Soon after picking, pulp is removed from seed which are planted in shaded nursery beds or baskets. Transplant in few months (when ca 0.6 m tall) into shaded fields at 2.4 m x 2.4 m or 3.6 m x 3.6 m. Spacing is closer if soils are poor and elevations above 300 m. Fields should remain shaded for 3 years. Remove floral buds until trees are 5 years old. Cocoa is of ten intercropped with other trees of economic value, as bananas, rubber, oil palm, or coconut. Weeding is by hand or herbicides. Irrigation may be practiced, but drain ditches should always be provided to prevent excess water. Responds to fertilizers, mostly in the absence of shade; recommended is 5 cwt urea, 2.5 cwt triple superphosphate, 10 cwt potassium sulfate per hectare. Windbreaks are usually provided.

Although fruits mature throughout the year, usually only two harvests are made. In West Africa, the main harvest begins in September, extends to February, with a second smaller harvest in May–June. From fertilization to harvesting the fruit requires 5–6 months. Harvest season lasts about 5 months. Pods are cut from trees and allowed to mellow on the ground. Then pods are cracked and the beans removed, the husks are burned. Beans are fermented in leaf-lined kegs 2–8 days before drying in sun, at which time they change from purple to brown. Beans are then bagged and shipped. Further processing includes roasting, crushing, and separating out the kernel, grinding the nibs and extraction of about half of the fat.

•anaerobic and aerobic with yeasts and bacteria •enzymatic changes associated with death of embryo

*COCOA BEANS & PRODUCTS*				Year
*HARV.ED AREA (HA)*				1995
ANGOLA				2,200
CAMEROON				360,000
CENT AFR REP				1,100
COMOROS				67
CONGO, REP				6,100
GABON				15,000
GHANA				950,000
GUINEA				5,000
COTE DIVOIRE				1,950,000
MADAGASCAR				4,600
NIGERIA				430,000
SAO TOME PRN				24,000
SIERRA LEONE				3,000
TANZANIA				4,300
TOGO				21,400
UGANDA				11,000
CONGO, DEM R				22,500

For more statistic on harvested area of cocoa refer to FAO statistic databases on agriculture. Then choose commodity review option. Then choose the type of information you are looking to: geographic and temporal.

Fermented cocoa beans have to be dried to reduce the humidity of the bean from 60% to 6 %. Drying also eliminates toxicity and improves the flavour of the bean. The tecniques to dry cocoa beans can be divided into two main categories: traditional and appropriate tecnologies and modern drying equipment. Into the first category we include all tecniques that use local available resources (raw inputs, local know-how, low-energy inputs). The second group is highly capital intensive and needs extensive imported equipment and know-how. Presently there exist a wide range of local drying tecniques and the differences depend, largely, on the local climatic conditions. For instance in countries where annual sun exposure is low and rainfall is high throughtout the year, beans have to be dried artificially. Modern drying equipment is used in huge plantations where volumes and economies of scale justify it.

Drying cocoa beans in Venezuela (cl. Fundación Nacional del Cacao, Venezuela)

The world low production yield is 29 kg/ha in American Samoa, an international production yield of 346 kg/ha, and a world high production yield of 2,000 kg/ha in Haiti. Yields of 3,375 kg/ha of dry beans are possible on good plantations. The oil content (35–50%) suggests potential oil yields of more than 1750 kg/ha. Average yields range from 0.5–10 kg/tree; 2.25 MT beans/ha. Over 3375 kg/ha of dry cacao beans have been produced on plantations well-manured, well-shaded, and with excellent control of weeds, pests and diseases. In 1980, the US is estimated to have consumed more than 75,000 MT of cocoa butter, in a business amounting to nearly $600 million. Chocolate manufacturers consumed nearly half. One ton went into suppositories, 10 to 20% of which are made with a cocoa butter base. Two-thirds of the world's production presently comes from Ghana, Nigeria, and Ivory Coast in West Africa, and one-third from Brazil and Dominican Republic. Major consumers are United States, West Germany, Netherlands, and United Kingdom. Cocoa is produced in tropical countries, but is processed and consumed in temperate countries.

Production¹
	1991-93	1994	1995	1996²
	Average
	*'000 tonnes, raw value*
World total	2 410	2 487	2 832	2 510
Brazil	330	330	215	180
Dominican Rep.	48	58	55	55
Ecuador	92	81	85	85
Cameroon	100	100	120	120
Côte d'Ivoire	749	809	1 200	950
Ghana	265	270	375	300
Nigeria	148	135	145	150
Indonesia	201	271	295	330
Malaysia	223	177	120	120
¹Production of beans in crop year beginning 1 October in the year shown. ² Provisional.

For more statistic on production of cocoa beans refer to FAO statistic databases on agriculture. Then choose commodity review option. Then choose the type of information you are looking to: geographic and time.

World cocoa prices remained relatively firm in 1996, the ICCO daily price closing at 68 US cents per pound in the third quarter, 5 US cents per pound higher than in the corresponding period of 1995, and substantially higher than in the early 1990s when they averaged 52 US cents per pound. Thus, cocoa prices have been on a continuous upward trend which commenced with the new International Cocoa Agreement of 1993.

Rising prices encouraged cocoa growers to improve yields through better crop husbandry, which, coupled with unusually favourable growing conditions, particularly in Africa, resulted in a record world cocoa production in 1995/96 of 2.8 million tonnes. This 14 percent increase from the previous season was for a large part due to Côte d'Ivoire, which produced an all-time record of 1.2 million tonnes, as well as a 40 percent rise in Ghana. Production also increased in Indonesia with new areas coming into bearing and productivity of young trees increasing. By contrast, major declines were recorded in Brazil, where the witches' broom virus was largely responsible for approximately halving production since the early 1990s. Drought conditions in 1995/96 also exacerbated this decline. However, with new plantings occurring in non-traditional cocoa-growing areas, an upward trend in output is expected in the near future. In Malaysia, the reasons for a decline in production in 1995/96 included adverse weather and continued conversion of land from cocoa to other crops, particularly oil palm, due to low cocoa prices in the early 1990s.

Prices
	1991-93	1994	1995	1996	1996	1996	1996	1996
	Average				Jan-Mar	Apr-Jun	July-Sep	Oct-Dec
ICCO daily
US cents/lb (450 g)	52	63	65	66	61	68	68	67
SDR/tonne	818	974	946	1 002	921	1 042	1 025	1 021
Ghana, spot London
£stg/tonne	747	996	974	...	948	1 070	1 025	...

Daily prices of cocoa beans (june 1, 1998)

World cocoa consumption, as measured by grindings of cocoa beans, rose in 1995/96 by 6 percent to 2.7 million tonnes, the highest annual growth rate in 10 years. All major consuming countries recorded increases, notably the Netherlands and the United States. However, prospects are for lower rates ofgrowth in 1996/97 as a reaction to the higher prices.

For more statistic on consumption of cocoa beans refer to FAO statistic databases on agriculture. Then choose commodity review option. Then choose the type of information you are looking to: geographic and time.

Imports¹
	1991-93	1994	1995
	Average
	*'000 tonnes, raw value*
World total	1 851	1 883	1 985
United States	394	312	283
Canada	39	29	41
EC-15	960	1176	1213
Poland	24	35	30
Czech Rep.	-	12	13
Area of former USSR	100	80	75
China	32	26	27
Japan	45	36	41
Philippines	9	9	10
Singapore	80	55	99
¹ Beans only.

Proposed EC regulations covering the use of vegetable fats in chocolate, the CBEs or cocoa butter equivalents, which is a measure of vegetable fats used to substitute cocoa butter, may affect the demand for cocoa in the future as chocolate is its main end-use. However, various studies have pointed out that the impact is likely to be minimal as the maximum level of substitution is estimated at 5 percent. In addition, it is speculated that with a greater presence of CBEs, consumers are likely to perceive the end product less as a chocolate, which is traditionally associated with cocoa and not with vegetable oils. Moreover, under current labelling laws, such a substitution may require the manufacturers to change the product name itself, from chocolate to something else, and affect its demand negatively. The overall impact on cocoa demand of the proposed regulation is expected to be small.

World stocks, which remained under one million tonnes until 1988, rose sharply thereafter, peaking at over 1.5 million tonnes in 1991, as low prices led to intervention purchasing under the previous International Cocoa Agreement. During that period, the ICCO acquired its buffer, which it now releases gradually into the market (the 38th liquidation sale of 4 250 tonnes of cocoa was carried out on 25 November 1996). With consumption exceeding production in 1994/95, stocks fell by 14 percent to 1.3 million tonnes, but stocks expanded in 1995/96, as production exceeded consumption by 100 000 tonnes. However, if the near balance between production and utilization seen in recent years continues, stocks should remain at relatively low levels, which in turn should continue to support prices.

Stocks¹
	1991-93	1994	1995	1996²
	Average
	*'000 tonnes*
World total ³	1 539	1 464	1 255	1 275
ICCO buffer stocks	235	179	128	77
¹ At the end of September of the year shown. ² Provisional. ³ ICCO data.

Cacao seeds are the source of commercial cocoa, chocolate, and cocoa butter. Fermented seeds are roasted, cracked and ground to give a powdery mass from which fat is expressed. This is the cocoa from which a popular beverage is prepared. In the preparation of chocolate, this mass is mixed with sugar, flavoring, and extra cocoa fat. Milk chocolate incorporates milk as well. Cocoa butter is used in confections and in manufacture of tobacco, soap, and cosmetics. Cocoa butter has been described as the world's most expensive fat, used rather extensively in the emollient "bullets" used for hemorrhoids.

Reported to be antiseptic, diuretic, ecbolic, emmenagogue, and parasiticide, cacao is a folk remedy for alopecia, burns, cough, dry lips, eyes, fever, listlessness, malaria, nephrosis, parturition, pregnancy, rheumatism, snakebite, and wounds (Duke and Wain, 1981). Cocoa butter is applied to wrinkles in the hope of correcting them (Leung, 1980).

Per 100 g, the seed is reported to contain 456 calories, 3.6 g H2O, 12.0 g protein, 46.3 g fat, 34.7 g total carbohydrate, 8.6 g fiber, 3.4 g ash, 106 mg Ca, 537 mg P, 3.6 mg Fe, 30 mg b-carotene equivalent, 0.17 mg thiamine, 0.14 mg riboflavin, 1.7 mg niacin, and 3 mg ascorbic acid. According to the Wealth of India, the edible pulp of the fruit contains 79.7–88.5% water, 0.5–0.7% albuminoids, astringents, etc.; 8.3–13.1% glucose, 0.4–0.9% sucrose, a trace of starch, 0.2–0.4% non-volatile acids (as tartaric), 0.03% Fe2O3 and 0.4% mineral salts (K, Na, Ca, Mg). The shell contains 11.0% moisture, 3.0% fat, 13.5% protein, 16.5% crude fiber, 9.0% tannins, 6.0% pentosans, 6.5% ash, and 0.75 theobromine. Raw seeds contain 0.24 mg/100 g thiamine, 0.41 riboflavin, 0.09 pyridoxine, 2.1 nicotinamide, and 1.35 pantothenic acid. The component fatty acids of cocoa butter are 26.2% palmitic and lower acids, 34.4 stearic and higher acids, 37.3% oleic acid, 2.1% linoleic and traces of isoleic. In g/100g the individual amino acids in the water soluble fractions of unfermented and fermented beans are lysine 0.08, 0.56; histidine 0.08, 0.04; arginine 0.08, 0.03; threonine 0.14, 0.84; serine 0.88, 1.99; glutamic acid 1.02, 1.77; proline 0.72, 1.97; glycine 0.09, 0.35; alanine 1.04, 3.61; valine 0.57, 2.60; isoleucine 0.56, 1.68; leucine 0.45, 4.75; tyrosine 0.57, 1.27; and phenylalanine 0.56–3.36 g/100g. Unfermented and fermented beans contain p-hydroxybenzoic acid, vanillic acid, p-coumaric acid, ferulic acid, and syringic acid, while the fermented beans also contain protocatechuic, phenylacetic, phloretic acid and the lactone esculetin and o- and p-hydroxyphenyl acids. Caffeic acid occurs in the unfermented beans (C.S.I.R., 1948–1976). According to an article in the Chicago Sun Times, people who suffer extreme depression as victims of unrequited love have an irregular production of phenylethylamine. Such individuals often go on chocolate binge during periods of depression. Chocolate is particularly high in phenylethylamine, perhaps serving as medication. Theophylline is a potent CNS and cardiovascular stimulant with diuretic and bronchial smooth muscle relaxant properties. Recently this drug was proven effective in preventing and treating apnea in premature infancy. Cocoa contains over 300 volatile compounds, including esters, hydrocarbonslactones, monocarbonyls, pyrazines, pyrroles, and others. The important flavor components are said to be aliphatic esters, polyphenols, unsaturated aromatic carbonyls, pyrazines, diketopiperazines, and theobromine. Cocoa also contains about 18% proteins (ca 8% digestible); fats (cocoa butter); amines and alkaloids, including theobromine (0.5 to 2.7%), caffeine (ca 0.25% in cocoa; 0.7 to 1.70 in fat-free beans, with forasteros containing less than 0.1% and criollos containing 1.43 to 1.70%), tyramine, dopamine, salsolinol, trigonelline, nicotinic acid, and free amino acids; tannins; phospholipids; etc. Cocoa butter contains mainly triglycerides of fatty acids that consist primarily of oleic, stearic, and palmitic acids. Over 73% of the glycerides are present as monounsaturated forms (oleopalmitostearin and oleodistearin), the remaining being mostly diunsaturated glycerides (palmitodiolein and stearodiolein), with lesser amounts of fully saturated and triunsaturated (triolein glycerides). Linoleic acid levels have been reported to be up to 4.1%. Also present in cocoa butter are small amounts of sterols and methylsterols; sterols consist mainly of b-sitosterol, stigmasterol, and campesterol, with a small quantity of cholesterol. In addition to alkaloids (mainly theobromine), tannins, and other constituents, cocoa husk contains a pigment that is a polyflavone glucoside with a molecular weight of over 1500, this pigment is claimed to be heat and light resistant, highly stable at pH 3 to 11, and useful as a food colorant; it was isolated at a 7.9% yield (Leung, 1980).

Reviewing the work on safrole, Buchanan (J. Food Safety 1:275.1978) concluded that it is the most thoroughly investigated methylenedioxybenzene derivative. The major flavoring constituent in sassafras root bark, safrole also occurs in basil (Perdue and Hartwell, eds., 1976), black pepper, cinnamon leaf oil, cocoa, mace, nutmeg, parsley, and star anise oil. When safrole was identified as a "low grade hepatocarcinogen, it was banned in root beer, and the FDA in 1976 banned interstate marketing of sassafras for sassafras tea. The oral LD50 for safrole in rats is 1950 mg/kg body weight, with major symptoms including ataxia, depression, and diarrhea, death occurring in 4–5 days. Ingestion of relatively large amounts of sassafras oil produced psychoactive and hallucinogenic effects persisting several days in humans. With rats, dietary safrole at levels of 0.25%, 0.5% and 1% produced growth retardation, stomach and testicular atrophy, liver necrosis, and biliary proliferation and primary hepatomas. Sutton (1981) reports the collapse and death of a 3-year old bitch that had eaten a 250 g package of cocoa. Postmortem examination revealed congestion of lungs, liver, kidney, and pancreas, and petechial and ecchymotic hemorrhage of the thymus, all compatible with acute circulatory failure. The stomach contained high concentrations of theobromine and/or caffeine. Though used cosmetically, cocoa butter has been reported to have allergenic and comedogenic properties in animals. Tyler (1982) produces a chart comparing various caffeine sources to which I have added rounded figures from Palotti (1977).

Cup (6 oz.) expresso coffee: 310 mg, Cup (6 oz.) boiled coffee: 100 mg, Cup (6 oz.) instant coffee: 65mg, Cup (6 oz.) tea: 10–50 mg, Cup (6 oz.) cocoa: 13 mg, Can (6 oz.) cola: 25 mg, Can (6 oz.) coca cola: 20 mg, Cup (6 oz.) mate: 25–50 mg, Can (6 oz.) pepsi cola: 10 mg, Tablet Caffeine: 100–200 mg, Tablet (800 mg) Zoom (Paullinia cupana): 60 mg.

In humans, caffeine, 1,3,7-trimethylxanthine, is demethylated into three primary metabolites: theophylline, theobromine, and paraxanthine. Since the early part of the 20th century, theophylline has been used in therapeutics for bronchodilation, for acute ventricular failure, and for long-term control of bronchial asthma. At 100 mg/kg theophylline is fetotoxic to rats, but no teratogenic abnormalities were noted. In therapeutics, theobromine has been used as diuretic, as a cardiac stimulant, and for dilation of arteries. But at 100 mg, theobromine is fetotoxic and teratogen (Collins, FDA By-lines No. 2, April 1981). Leung (1980) reports a fatal dose in man at 10,000 mg, with 1,000 mg or more capable of inducing headache, nausea, insomnia, restlessness, excitement, mild delirium, muscle tremor, tachycardia, and extrasystoles. Leung also adds "caffeine has been reported to have many other activities including mutagenic, teratogenic, and carcinogenic activities; ... to cause temporary increase in intraocular pressure, to have calming effects on hyperkinetic children...to cause chronic recurring headache..."

Reported from the South and Middle American Centers of Diversity, cocoa, or cvs thereof, is reported to tolerate some diseases, heavy soils, laterite, low pH, photoperiod, shade, slope, and waterlogging (Duke, 1978). Several subspecies and forms of cacao have been recognized, from which a great number of cvs have been developed. Some cvs are named according to the place where they were found or developed. Others are classified as 'Criollo' types which have elongated, ridged, pointed fruits and white cotyledons and 'Forastero', with short, roundish, almost smooth fruits and purplish cotyledons. Hybrids have been obtained with other species, e.g. Th. grandiflora, mainly to incorporate disease-resistance. (2n = 20)

For every kilogram of dry beans, there can be 2 kg of pod meal; indicating a 1:2 seed:pod ratio. To convert production figures into pod waste figures, this suggests we multiply by two. Pod meal contains ca 12.6% moisture, 7.6% ash, 8.1% protein, 34.8% crude fiber, 3.3% fat, and 33.6% N-free extract. One hundred kg cacao pod meal has the same feeding value as 96–97 kg chopped corn (including husks). Prunings could amount to 1–8 MT/ha/yr, depending on biological and environmental variables. During the third year, main branches may be reduced to 3 or 4, and thenceforth, excess limbs and diseases tissues should be removed. For each MT of production, it seems safe to conclude there will be 2 MT of pods and 2 MT of prunings as residue, perhaps more in unshaded cacao. Shade trees might best be selected on basis of (1) nitrogen fixed, (2) fuelwood produced, (3) nonantagonism or amelioration of cacao. Seedling cacao does best with only 25% full sunlight, saplings with closer to 50%. Species of energy-fixing species of Albizia, Erythrina, Gliricida, Inga, Leucaena, Musanga, Peltophorum, and Terminalia have been recommended as shade trees or "Madre de Cacao". (Purseglove, 1968)

Midges are thought to be the pollinators of cacao, but aphids, ants, thrips, wild bees, or a combination of these are also suspect. Cacao grows in areas with high humidity; several hundred fungi have been reported as attacking this tree. However, the most important fungi that cause diseases which must be controlled include the following: Armillaria mella (Collar crack), Botryodiplodia theobromae (Pod rot), Botryobasidium salmonicolor (Pink disease), Calonectria rigidiuscula (Green point cusion-gall), Cephaleuros virescens (Algal spot), Ceratobasidium stevensii (Thread blight), Ceratocystis fimbriata (Canker), Corticium incisum (Thread blight), Fomes lamaensis (Brown rot), F. lignosus (White rot), F. noxius (Brown crust), Marasmius byssicola (Brown thread), M. perniciosus (South American witches broom), M. scandens (White thread), M. trichorrhizus (Brown thread), Monilia roreri (Gray pod rot), Nectria cacaoicola (Pod rot), Phytophthora palmivora (Black pod), Rosellinia bunodes (Root rot), R. pepo (Root rot), Septobasidium tanakae (Felty fungus), Sphaerostilbe repens (Violet root rot), Taphrina bussei (Witches broom), Thielaviopsis paradoxa (pod rot), Trachysphaera fructigena (Mealy pod), Ustilina zonata (Collar rot), and Verticillium dahliae (Sudden death). Bacteria known to cause disease in cacao include: Agrobacterium tumefasciens, Bacillus megatherium, B. subtilis, B. undulatus, Bacterium accendens, B. aceti, B. orleanense, B. xylineum, B. xylmoides, and B. xylum. Golden (p.c. 1984) lists the following nematodes: Aphasmatylenchus nigeriensis, Criconemella goodeyi, Helcotylenchus cavenessi, H. concavus, H. microcephalus, H. multicinctus, Hoplolaimus seinhorst, Meloidogyne incognita, M. incognita acrita., M. javanica, M. sp., Paratylenchus arculatus, Pratylenchus brachyurus, P. coffeae, P. sp., Rotylenchulus reniformis, Scutellonema clathricaudatum, Tylenchorhynchus annulatus, T. nudus, Xiphinema ebriense, X. elongatum, X. ifacolum, X. nigeriense, and X. setariae. Viruses isolated from cacao include: Akaran, Apoplectic disease, Asalu, Ilesha, Konongo, Kpeve cacao, Mottle leaf, Necrosis, New Juaben (B.C.), New Juaben cacao, Offa Igbo (Nigeria) cacao, Offa Igbo 1 and 2, Olanla 1 and 2, Red mottle, Swollen-shoot, Trinidad cacao, Vein clearing, and Viruses 1A, 1B, 1C, and 1M. Cacao trees may be parasitized by Cuscuta campestris, C. cublinclusa, and Phthirusa theobromae.

Analysing 62 kinds of biomass for heating value, Jenkins and Ebeling (1985) reported a spread of 19.04 to 17.97 MJ/kg, compared to 13.76 for weathered rice straw to 23.28 MJ/kg for prune pits. On a % DM basis, the hulls contained 67.95% volatiles, 8.25% ash, 23.80% fixed carbon, 48.23% C, 5.23% H, 33.19% O, 2.98% N, 0.12% S, and undetermined residue.

•Kennedy AJ (1995) Cacao, Theobroma cacao (Sterculiaceae). In: Smartt J, Simmonds NW (eds.) Evolution of crop plants. Longman, London: pp. 472-475 •Sauer JD (1993) Historical geography of crop plants. CRC, Boca Raton, FL: pp. 162-167 •West JA (1992) A brief history and botany of cacao. In: Foster N, Cordell LS (eds.), Chilies to chocolate: food the Americas gave the world. Univ. of Arizona, Tucson: pp. 105-121 •Sokolov R (1991) Why we eat what we eat. Summit, New York

The development of an electronic, annotated, cocoa literature bibliography was started in 1993. This is a continuously ongoing process, which is proving to become a very useful by-product of this project. To date 8154 cocoa literature references have been collected, of which about 1000 are from the pre-W.W.II literature. Since the mid-seventies, the collection of annotated references is facilitated by the electronic databases of the Commonwealth Agricultural Bureau, The Royal Institute for the Tropics and Current Contents. But beside these electronic databases, the value of this cocoa literature database lies in the addition of the references from the period before computerised bibliography collections became widely available.

The database is not only useful as a standard tool for checking references, and literature reviews. Analysis of the data also gives some insight in the priorities of cocoa research and division of research efforts in those various fields, and historical trends in the division of research attention (for example 23% of the literature is devoted to the topic of crop protection, of which 51% is related to diseases).The file is slightly over 6 MB large, so downloading might take a while. This bibliography will be regularly updated. For the moment the database is only available in its current form, in due course a searchable database might be offered.

Prices at the time of London close	Current	Previous
	1 June 1998	29 May 1998
ICCO daily price (SDRs/tonne)	1305.98	1327.83
ICCO daily price ($US/tonne)	1744.57	1773.14
*London futures (£ sterling/tonne)**	1116.667	1140.667
New York futures* ($US/tonne)**	1674.000	1700.333