Cocoa (cacao)

Description

Cocoa

Scientific name: Theobroma cacao

Rank: Species

Higher classification: Theobroma

Family: Malvaceae

Kingdom: Plantae

Order: Malvales

Local Names

English (Mother of cocoa, Mexican lilac, quikstick)

Cocoa may also be referred to as cacao, koko or Kacao and originates from upper Amazon region of South America.

 

General information.

Cocoa is an evergreen tree in the Malvaceae family that is grown for its seeds (beans), which are primarily used in the production of chocolate.

 

A cocoa tree is a branching tree with simple, pointed (lanceolate) leaves that can reach up to 10 cm in width and 61 cm in length. The tree bears clusters of pale-yellow flowers with five petals and sepals each. Cocoa pods (drupes) can be green-white, yellow, purplish, or red in color, with 20-50 seeds arranged in five distinct rows.

 

How do cocoa fruits look?

The ripe cocoa fruits are yellow, greenish, yellow-red, and red to red-brown.

They have the shape of American football balls. They grow to be about 25 cm long and have a thick shell. In the center is a white, sweet pulp with 25 to 50 seeds arranged in five rows. Each one is about 2-3 cm long. They are encased in white mucus. Criollo cocoa fruit.

We have three main varieties of cocoa: 

-Criollo.

-Forastero.

-Trinitario.

 

i). Criollo

 

Criollo is a noble and extremely rare group of many varieties. It now accounts for less than 1% of global production, despite dominating 200 years ago. It is indigenous to Colombia and Venezuela.

 

It is also grown commercially in Peru, Mexico, Sri Lanka, Colombia, Madagascar, and the Caribbean region. 

 

Types of Cocoa Criollo example from Venezuela

Criollo guasare

It is grown south of Lake Maracaibo. Its plantations are currently quite small. It is distinguished by a green fruit with a thin, slightly rough shell. This is a high-quality cocoa.

Criollo chuao

Its among the most famous type cocoa grown in the world, it is mainly grown in the Chuao region of Aragua state. It is classed as fine cocoa. 

Criollo porcelain

It is grown in the southern regions of Lake Maracaibo. It has a distinct flavor and is considered extremely fine cocoa by experts. It is thought to have the highest genetic quality of all Venezuelan cocoa trees.

ii). Forastero

Forastero is native to the Amazon basin, which is why it is also known as Cacao Amazonico. Because of its high yield, this cocoa is also known as Cacao Corriente or ordinary cocoa. It is currently grown in many regions, primarily in Africa (Ghana and Côte d'Ivoire). The Spaniards first brought this cocoa from Venezuela. According to various sources, it accounts for 85-95% of global production. The relatively low requirements and ease of cultivation account for such a large share. It is relatively resistant to diseases and pests. It grows faster and produces more than the other groups.


The appearance of individual Forastero varieties varies. There are numerous subspecies, including Cundeamor, Calabacillo and Amelonado.

iii). Trinitario

Trinitario cocoa has a delicate flavor. It is a cross between the two varieties mentioned above. It was chosen during the seventeenth century. The trees were brought to Trinidad from Venezuela. It was a big hit. Trinidad produced the best cocoa beans for several decades. 

Trinitario's global market share is currently less than 10%. The aroma of Trinitario is forastero, and the flavor is delicate criollo.




Uses

Cocoa seeds have a high fat content and thus provide an energy-rich and delicious food. Cocoa is grown in all humid and tropical countries. Côte d'Ivoire (the world's largest cocoa producer) is the leading cocoa producer in Africa, followed by Ghana, Nigeria, and Cameroon.

Chocolate, cocoa powder, and butterfat are the main products made from cocoa beans which are all consumed by humans. Butterfat is also used in cosmetics and pharmaceutical products, but the amount used is insignificant in comparison to that used in chocolate production. Raw cocoa (dried cocoa seeds) is the most sought-after product on the international market, and it is used to make cocoa butter, cocoa powder, and chocolate.




Climatic condition soil and water.

Cocoa grows in the so-called under-storey of primary forests and is associated with a number of palm species as well as a number of other tree species. For example, in rain forests, tree varieties from the upper storey, primarily single trees overtopping the forest canopy, lose their foliage during the months of shorter daylight hours. The increased light encourages the development of cocoa blossoms, and the falling leaves provide organic material enrichment.

The plantations can survive on 1250 mm of rainfall per year if the annual distribution is even (100 mm per month). Heavy clouds and high humidity can compensate for short drought periods. The annual average temperature should be around 25° C. Harvesting periods are reduced to a few months per year in regions with extensive wet periods or large seasonal temperature fluctuations. Cocoa produces fruit almost all year in regions with a balanced climate and only minor temperature and rainfall fluctuations. As a result, cocoa is a typical crop of the tropical lowlands. If other conditions are favorable, it can also be grown at higher altitudes.

Cocoa has shown to develop more quickly in areas without a dry season than in the major production areas of West Africa, where growth is slowed by drought during certain months of the year.

Cocoa plantations should have deep, well-drained soil with adequate water retention. Soils with a high available moisture-storage capacity can compensate for lack of rain. The pH of the solution should be between 4.0 and 7.5. It is critical to ensure that there is enough organic material available. Cocoa trees can live for more than a century. Naturally occurring cocoa crops reproduce through lateral shoots that can appear at any height on the trunk. Natural vegetative proliferation occurs when small rodents and apes spread the seeds.

 

Propagation and planting

The natural site requirements of cocoa should be followed when selecting a location for a new plantation. Sites with alluvial soils that are resistant to waterlogging are ideal. Other appropriate locations include irrigated form wells and hollows. Steep and convex slopes are unsuitable locations. When establishing a new plantation, take care to replicate the natural structure of forests as closely as possible. This means that in the agroecosystem, all of the varieties that will be cultivated alongside cocoa should be planted at the same time (or even before) the cocoa.

The best method is to leave an area open for natural growth and plant tall-growing trees that will quickly provide cover, such as bananas and manioc, and then plant cocoa in between them later. The biological activity of the soil is maintained in this manner, and the cocoa mycorrhiza can begin to develop immediately.

Cocoa is typically planted as seedlings, which are simple and inexpensive to produce. To establish seed gardens, vegetative propagation via rooted cuttings or budding is used. In a shaded nursery, seedlings are typically raised in polythene bags. 

At the age of 4 - 6 months, young plants are planted in the field 3 - 4 m apart. Young trees require shade to reduce irradiance, buffer the microenvironment, and promote proper tree shape and habit. The need for shade is reduced when a closed canopy is formed. Cocoa can only be grown without shade under the most favorable soil and nutrient conditions.

In order to extend the economic life of plantations, some shade is usually required to reduce moisture stress and the incidence of insect damage.

Shade can be obtained by either thinning the forest or planting shade trees. Shade trees are common in South-East Asia, where they are mostly seedless and Mother of cocoa. 

Hedges of leguminous shrubs are frequently used for temporary side protection between rows as well as a source of mulch. Cocoa can also be grown as an intercrop with coconuts.




Main varieties grown are

Trinitario

-This variety is a hybrid of Criollo and Forastero.

-The pods can be long or short, and red or yellow.

-It produces reasonably high-quality cocoa.

 

Forastero (Amelonado) (Amelonado)

-The pods are short, yellow, smooth, and have shallow furrows.

-This variety yields well, but the quality is not as high as that of Criollo. It is widely grown in Africa.

Criollo

-When Criollo pods are ripe, they are long, yellow or red, with deep furrows and large warts.

-This variety does not produce as much as the others, but the cocoa is of very high quality.

-It is mostly grown in the United States.

 

Harvesting

The most vital characteristics of cocoa are dependent on proper processing, which begins with harvesting and ends with storage. Pod development takes about 6 months from seed to maturity. When the pods are completely ripe, harvesting can begin. An orange discoloration of the shell distinguishes many Trinitario types with their red and dark violet pods. When other varieties are ripe, they turn yellow.

Depending on the region and weather conditions, there are usually one or two harvesting phases that last several months. It is best to harvest all of the ripened pods every 2-3 weeks to ensure uniform ripeness of the harvested pods. Each week during peak production, pods are harvested. 

To avoid damaging of the bark, use a sharp knife or other suitable instrument to cut off the pods at the base of the blossom. 

 

POST-HARVEST PROCESSES 

After harvest, the cocoa fruit is fermented, dried, and stored. Farmers remain vulnerable to production losses during these processes and the quality and flavor of the product is defined by the environment and the methods used. 

 

Fermentation 

There are various ways in which farmers can engage in the process of cocoa fermentation. After the cocoa beans and pulp are removed from the husk, smallholders typically cover the heaps of cocoa with plantain or banana leaves and let them ferment for approximately five days. This traditional approach to fermentation, however, is susceptible to environmental risk factors. Periods of intense rainfall increase the time required for fermentation. Temperature changes, droughts, and prolonged dry seasons affect the flavor and overall quality of the product. Unlike farmers in West Africa, cocoa farmers in Latin America tend to ferment the cocoa pulp surrounding the beans using wooden boxes. In Indonesia, farmers rarely take part in the fermentation process because their production is valued mostly for cocoa butter which is unaffected by fermentation.

 

Drying 

The next step after fermentation is the drying of the cocoa beans. Under inadequate methods and circumstances, drying can result in production losses and loss of quality. Farmers may either sun dry their beans or use an artificial drying technique. The former is common in countries that have a significant dry period during which to carry out drying and it involves placing the cocoa seeds on a surface exposed to the sun either on mats, trays, or concrete. Artificial drying involves the use of an artificial source of heat such as fires. Intensive rainfall can cause molding of cocoa beans and reduce quality. While temperature changes alter the time required for drying, droughts and dry periods will increase the speed at which cocoa dries. CSC recommends the use of solar dryers, which are easy to build using wood and clear plastic. Solar dryers avoid the GHG emissions of artificial drying and protect cocoa from excessive humidity.

 

Storage

In temperate climates, cocoa can be safely stored for years. High temperatures and humidity, on the other hand, cause a rapid infestation of storage pests and infection with mould fungi in the moist tropics. Because cocoa is highly hygroscopic, even a well-dried product can increase in moisture content by up to 10% in areas with 80-90% humidity, reducing its storage capacity. For storage, the critical moisture content is 8%.

Cocoa should be stored in air-permeable sacks for a short period of time on the production site, and the sacks should be stacked on wooden planks or boards. 

Sacks made of organic material that have been treated with pesticides should be avoided since the cocoa butter component of the cocoa shell is an excellent solvent for chlorinated hydrocarbons, which can diffuse through the outer shell and into the cocoa seed when they come into contact with it. In such cases, tests have revealed that limits for certain agricultural poisons were exceeded despite the fact that no pesticides had ever been used on the site.

The storage area should be well-ventilated at all times, with the inside temperature remaining below the outside temperature.

It is common practice on conventional plantations to gas the cocoa with methyl bromide to protect it from storage pests. However, the use of methyl bromide is no longer permitted. 

Tetraline soap, hydrogen phosphide, and prussic acid are also employed. It is not permitted to use insecticides against storage pests or to gas the beans on organic cocoa plantations. Cocoa beans should be stored at low temperatures in dark, dry, well-ventilated rooms. Short-term storage temperature: approximately 16°C; relative humidity: 55% Long-term storage temperature: 11°C; relative humidity: 55




References

CABI Crop Protection Compendium. (2008). Theobroma cacao datasheet. Available at: http://www.cabi.org/cpc/datasheet/53662. [Accessed 13 November 14]. Paid subscription required. Jürgen Pohlan, H. A. & Pérez, V. D. (2010). In Verheye, W. H. (ed) Soils, Plant Growth and Crop Production. Eolss Publishers Company Limited. Chapter available at: http://www.eolss.net/sample-chapters/c10/e1-05a-43-00.pdf. [Accessed 13 November 14] Free to access Crane, J. H., Balerdi, C. F. & Joyner, G. Cocoa (Chocolate Bean) Growing in the Florida Home Garden. University of Florida IFAS Extension. Available at: http://edis.ifas.ufl.edu/pdffiles/HS/HS30700.pdf. [Accessed 13 November 14]. Free to access.


Common Pests and Diseases

Diseases

Category : Oomycete

Black pod (Phytophthora pod rot) Phytophthora palmivora
Phytophthora megakarya
Phytophthora capsici

Symptoms
Translucent spots on pod surface which develop into a small, dark hard spots; entire pod becomes black and necrotic with 14 days of initial symptoms; white to yellow downy growth on black areas; internal tissues become dry and shriveled resulting in mummified pods
Cause
Oomycete
Comments
Disease occurs in all cocoa growing areas; P. megakarya is most destructive in Central and West Africa whereas P. capsici is most common in Central and South America
Management
Protective sprays of copper containing fungicides in combination with systemic fungicides are often recommended to control the disease; cocoa plants should be well spaced to allow good air circulation through the plantation; mummified pods should be removed and destroyed to reduce spread

Category : Viral

Cocoa swollen shoot Cocoa swollen shoot virus (CSSV)

Symptoms
Swelling of leaves and shoots; red leaf veins, notably in young leaves; chlorotic patches next to leaf veins; chlorotic spots or flecks on leaves mottled, smooth pods with reduced beans; mottled coloration on pods; stems may develop swellings at nodes or internodes and shoot tips; progressive defoliation may occur ultimately leading to the death of the tree.
Cause
Virus
Comments
Only occurs in West Africa. Major problem in Togo, Ghana, Cote d'Ivorie and Nigeria; transmitted by mealybugs. The Swollen Shoot Virus is not native to cocoa but jumped into the cocoa from trees that grew in the rain forests of W. Africa (e.g. Cola chlamydanta, Ceiba pentandra, Adansonia digitata, Cola gigantean and Sterculia tragacantha). The virus is a badnavirus within the family Caulimoviridae.
Management
Infected trees and those surrounding them should be removed and destroyed (up to 5 m from infected tree if less than 10 trees are infected and up to a distance of 15 m if greater than 100 trees are infected) to prevent further spread; a gap should be placed between cocoa plantations of at least 10 m (33 ft) and it may be possible to isolate cocoa plantations using a non-host crop such as oil palm growing between plantations.

Category : Fungal

Frosty pod (Monilia pod rot, Watery pod rot) Moniliophthora roreri

Symptoms
Spots on surface of immature pods; spots turning brown and rapidly enlarging to cover entire pod surface; disease affects only actively growing pods.
Cause
Fungus
Comments
Causes serious losses in South-Western parts of South America; spores are dry and powdery and are spread easily by water movement, wind or movement of pods; disease spread is highest during periods of high rainfall.
Management
Planting cocoa varieties that produce pods during the dry season allows the pod to avoid the disease; pods showing symptoms of disease should be removed to prevent spread; application of copper containing fungicides will help reduce disease incidence.

Witches' broom Moniliophthora perniciosa

Symptoms
Characteristic proliferation of shoots and brooms from bud; production of branches which do not produce fruit; distorted pods with green patches which give an appearance of uneven ripening.
Cause
Fungus
Comments
One of the most devastating cocoa diseases in South America; disease is widespread throughout South America, the Caribbean and Panama; spread of disease greatly influenced by humidity with emergence favored by high temperature and high humidity (>80%).
Management
Good sanitation is the most effective method of controlling the disease; material known to be infected should be removed and destroyed; removal of infected material can be difficult as there may be no visible symptoms; new fungicides and resistant cocoa varieties are being developed to help control the disease.

Pests

Category : Insects

Cocoa mealybugs Planococcus spp.
Pseudococus spp.

Symptoms
Flattened oval to round disc-like insect covered in waxy substance on tree branches; insects attract ants which may also be present; insect colony may also be associated with growth of sooty mold due to fungal colonization of sugary honeydew excreted by the insect; symptoms of directinsect damage not well documented but trees may exhibit symptoms of cocoa swollen shoot (see disease entry)
Cause
Insect
Comments
Insects have a wide host range; often tended by ants which farm them for their sugary honeydew secretions; transmit Cocoa swollen shoot virus
Management
Mealybugs can potentially be controlled by natural enemies such as lady beetles but are commonly controlled using chemicals; chemical pesticides may also decrease populations of natural enemies leading to mealybug outbreaks

Cocoa mirid Distantiella theobroma
Sahlbergella singularis
Helopeltis
spp.
Monalonion spp.

Symptoms
First symptoms appear as tiny puncture wounds on young stems and pods; these punctures quickly turn necrotic, creating black patches which may develop into cankers; discolored bark; terminal leaves and branches dying back; trees unproductive; adult insect is a slender red or brown insect with long legs and antennae; adults are typically between 7 and 10 mm long.
Cause
Insect
Comments
Adult females lay their eggs in the bark of the tree and can lay between 30 and 40 eggs.
Management
In African countries, the insect is usually controlled by chemical eradication programs consisting of two sprays conducted one month apart to target different stages of the insects development; mirids have been shown to be attracted to trees positioned in direct sunlight and providing shade cover in the form of forest to cocoa trees can be used as part of an integrated control method; do not interplant with other hosts such as cashew, tea, sweet potato, guava, cotton or mango - the trees used must be non-hosts; some species of ant, e.g black ants, can be used as a biological control agent.

Cocoa pod borer Conopomorpha cramerella

Symptoms
Holes in cocoa pod husk caused by insect larvae entering and exiting the pod; uneven and premature ripening of pods; seeds sticking together inside pod due to insect eating surrounding tissue; harvested cocoa beans clump together and can be very difficult to remove from the pod; adult insect is a small brown moth; larvae are cream in color and approximately 1 cm (0.4 in) long; larvae change color to green when they emerge from the pod to pupate.
Cause
Insect
Comments
Female moth lives for approximately 5-7 days and can lay 100-200 eggs; eggs are laid on the surface of cocoa pods; larvae develop for 14-18 days before pupating.
Management
Sleeving pods in plastic bags while they mature prevents the insect from reaching the pods, sleeves should be applied when pods are 8-10 cm (3-4 in) long; borer populations can be held in check by black ants and weaver ants; chemical control is often economically unfeasible due to the high price of pesticides compared with the low price of cocoa but, where available, small amounts of contact pyrethroid or carbamate applied to underside of cocoa leaves can keep borers below an economically damaging level.
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