**Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain**

George Afrane1 and Augustine Ntiamoah2 *1University of Ghana, Department of Food Process Engineering, 2Koforidua Polytechnic, Department of Energy Systems Engineering, Ghana* 

#### **1. Introduction**

50 Pesticides in the Modern World - Risks and Benefits

summary).

individuals of the Asian citrus psyllid, *Diaphorina citri* (Homoptera: Psyllidae). *Kyushu Plant Protection Research*, Vol.53, pp.95-98. (In Japanese with an English

> Cocoa, *Theobroma cacao L.,* is a major cash crop cultivated in the tropical regions of West Africa, the Caribbean, South America and Asia. In West Africa, where over 70% of the world's cocoa is produced – with about 21% coming from Ghana - it is a significant component of the rural economy, as the industry is dominated by large numbers of smallholder peasant farmers who depend on the crop for their livelihood (Acquaah, 1999; Appiah, 2004). Like all living organisms, the cocoa plant can also be attacked by a wide range of pests and diseases. When this happens expected production targets are not met, and the economies of the producer nations are adversely affected. Preventive and curative measures are therefore necessary in the cocoa industry to maintain and even increase output (Akrofi and Baah, 2007).

> While non-chemical means of managing pests and diseases in the industry are widely recommended for health and other reasons, the use of some amounts of chemicals in the form of fertilizers, insecticides and fungicides is unavoidable in the effective management of cocoa farms (Moy and Wessel, 2000; Opoku et al., 2007; Adjinah and Opoku, 2010). Their use is therefore expected to increase with time. Indeed in the twenty-year period from 1986- 2006, the use of fertilizer world-wide increased by almost 250% (UNEP, 1991). The same trend applies to pesticides, although they are more difficult to monitor partly because of the secrecy that goes with the continued production and use of banned substances. The trends suggest quite clearly however, that much of the increase in world food production can be attributed to the response of crops to increased use of fertilizers and pesticides (UNEP, 1991). Fortunately, there has always been a clear appreciation of the potential deleterious effects of the chemicals used in the cocoa industry since the 60s, and standards have been set by FAO and WHO for acceptable levels of residues in the beans exported to other countries.

> The goal of maintaining high levels of agricultural productivity and profitability while reducing pesticides use presents a significant challenge. There are repeated cases of excessive levels of pesticide residues being found in agricultural produce and the safety of these products has become an issue of concern. Recently, changes in regulations in the European Union (EU), North America and Japan have called for a reflection on crop protection practices in cocoa and other commodity crops (ICCO, 2007). The quality of cocoa

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 53

when soil conditions deteriorated the land could be left to the cocoa trees and other tracts tilled in the shifting-cultivation systems of farming (Acquaah, 1999). Because of the prominence that the crop had began to gain in the economy, even before World War II, government was seriously alarmed when the swollen shoot disease was discovered in 1936. In the process of combating this disease, a permanent research center was established at Tafo, in the Eastern Region, and product quality inspectorate, grading of beans, extension services and proper engagement of farmers in the growth of the crop were initiated (Acquaah, 1999). Since then government has continued to offer technical assistance, financial

Over the last decade, as a result of government intervention, cocoa production has picked up, reaching a peak of 740 thousand metric tonnes in the 2005/2006 season (Aryeetey *et al*, 2007). Constituting 7.3% of the Gross Domestic Product of the country, it is second only to gold, which first overtook cocoa as the highest foreign exchange earner in 1992; a trend which still continues. Agriculture contributes about 35% of Ghana's Gross Domestic Product (GDP) and 60% of total employment. The Cocoa Industry is the single largest contributor to agricultural GDP (16.5 %). It is estimated that about 65% of the country's agricultural workforce work either directly or indirectly in the cocoa industry. In Ghana cocoa is grown on small farms owned by individuals and families in the forest zones of Ashanti, Brong Ahafo, Western, Eastern and Volta regions. Thus the livelihood of about two million farmers and their dependants, mostly in the rural areas, depend directly on cocoa (Opoku *et. al,*

Although serious attempts have been made to process them locally, the majority of cocoa beans produced in the country are still exported. Government put a policy in place to process at least 50% by the end of the last decade. The enabling conditions created in free zone enclaves, led to the attraction of private foreign processing companies and the expansion of state-owned facilities. According to data from International Cocoa Organization, ICCO, 200,000 metric tonnes of cocoa grindings were achieved in Ghana in the 2009/2010 season. Compared to the production figure given in Table 1 for the same season, this constitutes about 32% of the beans produced. This means the government's

In spite of their peripheral role in the standard household menu - mainly as a dessert or snack, food products made from cocoa go through a long line of operations not normally found with other processed foods, as depicted in Figure 1 (Awua, 2002). Ripe cocoa pods are plucked from the trees and gathered together on clearings in the cocoa farms. After about ten days, all available hands, young and old, gather together to assist in the splitting of the pods and removal of the beans with their hands. (According to Owusu-Manu (1977), this could be a critical stage in the contamination process, with pesticides getting transferred from the workers to the wet beans.) The wet beans are collected together in a heap and covered with plantain leaves and plastic sheets for fermentation. After fermentation, the beans are dried in the sun on bamboo mats to a desired moisture content of around 7.5%. After dried cocoa beans have been received at the processing plant, they are inspected and thoroughly cleaned of all extraneous matter, such as sticks, stones, metal fragments, dust, loose shells, small fragments and clumps of cocoa beans. The cleaning process consists of a series of operations involving sieves, brushes, airlifts and magnetic separators to remove the

incentives and inputs like fertilizer and pesticides to cocoa farmers.

2006).

**2.1 Cocoa processing in Ghana** 

target for grindings was not achieved.

imported into the EU and elsewhere will be assessed based on traces of pesticides and other substances that have been used in the supply chain.

The cocoa bean has a high content of butter or fat which absorbs the active ingredients in insecticides. The acceptable levels of active ingredients in foods are determined by the committee on Pesticide Residue of FAO/WHO, known as the Codex Alimentarius Commission, CAC. Created in 1963 the CAC implements the Joint FAO/WHO Food Standards Programme which is aimed at protecting the health of consumers and ensuring fair trade practices in the international food trade (Moy and Wessel, 2000). The commission has set maximum levels of residue poisons in commodities going through the international market, including cocoa. If for any reason the residual levels in any commodity exceed the Codex levels, that particular commodity could be rejected by the importing country. Secondly, the accumulation of any chemicals in the cocoa fat may change the taste of the beans and eventually that of the chocolate made from them. This is known as tainting. It is therefore, the task of entomologists to ensure that recommended chemicals do not leave any residues, and that the dosage is the minimum that would give the optimum control under the agricultural conditions in the country.

In Ghana, significant gains have been made in the control of pests and diseases of the cocoa industry through the nationwide use of pesticides under government sponsorship and supervision. The growing global concerns about the effects of the increasing use of agricultural chemicals on farmers, consumers of agricultural produce and the ecology require a re-examination of the issues related to their application in the cocoa industry. This chapter examines the use and the impact of pesticides in cocoa production in Ghana - where data has been accumulated - as a representative country of the industry. The potential ecological impacts of chemicals in the cocoa industry are analyzed, using the modern tool of life-cycle assessment (Ntiamoah and Afrane, 2009). Life-cycle assessment, LCA, has gained such prominence in the environmental management discipline that the International Standards Organization has developed standards for its implementation (ISO 14040-14043, 1997-2000b). This particular analysis is based on primary farm-level data collected from a nationally representative sample of cocoa farmers, published data, results from research institutions, the Ghana Cocoa Board and other relevant sources.

#### **2. The Ghanaian cocoa industry in brief**

In Ghana, cocoa has played an important role in the economy of the country for over one century. Although the crop was believed to have been brought to the colonial Gold Coast as Ghana was then known - from Fernando Po, an island in the Gulf of Guinea, off the coast of Gabon, in 1879 and from Sao Tome in 1886, records show that in 1891, only twelve years after it first arrived here, cocoa was being exported as a cash crop (Acquaah, 1999, Adjinah and Opoku, 2010). From the 1910/1911 season, Ghana became the leading cocoa producer in the world, a position it held until 1977, when it was overtaken by the Ivory Coast. The country went from being the number one cocoa producer to a period in the early 80s when, as a result of drought, bushfires, low producer prices, diseases and general economic malaise, Ghana fell to the twelfth position and produced less than 160,000 metric tonnes in the 1983/1984 season (Adjinah and Opoku, 2010).

Cocoa became attractive as a cash crop in Ghana because of the lower cost involved in its cultivation, compared to a popular crop like palm, as well as the favourable natural conditions that existed in the forest belts. Cocoa could be grown along with other crops and when soil conditions deteriorated the land could be left to the cocoa trees and other tracts tilled in the shifting-cultivation systems of farming (Acquaah, 1999). Because of the prominence that the crop had began to gain in the economy, even before World War II, government was seriously alarmed when the swollen shoot disease was discovered in 1936. In the process of combating this disease, a permanent research center was established at Tafo, in the Eastern Region, and product quality inspectorate, grading of beans, extension services and proper engagement of farmers in the growth of the crop were initiated (Acquaah, 1999). Since then government has continued to offer technical assistance, financial incentives and inputs like fertilizer and pesticides to cocoa farmers.

Over the last decade, as a result of government intervention, cocoa production has picked up, reaching a peak of 740 thousand metric tonnes in the 2005/2006 season (Aryeetey *et al*, 2007). Constituting 7.3% of the Gross Domestic Product of the country, it is second only to gold, which first overtook cocoa as the highest foreign exchange earner in 1992; a trend which still continues. Agriculture contributes about 35% of Ghana's Gross Domestic Product (GDP) and 60% of total employment. The Cocoa Industry is the single largest contributor to agricultural GDP (16.5 %). It is estimated that about 65% of the country's agricultural workforce work either directly or indirectly in the cocoa industry. In Ghana cocoa is grown on small farms owned by individuals and families in the forest zones of Ashanti, Brong Ahafo, Western, Eastern and Volta regions. Thus the livelihood of about two million farmers and their dependants, mostly in the rural areas, depend directly on cocoa (Opoku *et. al,* 2006).

#### **2.1 Cocoa processing in Ghana**

52 Pesticides in the Modern World - Risks and Benefits

imported into the EU and elsewhere will be assessed based on traces of pesticides and other

The cocoa bean has a high content of butter or fat which absorbs the active ingredients in insecticides. The acceptable levels of active ingredients in foods are determined by the committee on Pesticide Residue of FAO/WHO, known as the Codex Alimentarius Commission, CAC. Created in 1963 the CAC implements the Joint FAO/WHO Food Standards Programme which is aimed at protecting the health of consumers and ensuring fair trade practices in the international food trade (Moy and Wessel, 2000). The commission has set maximum levels of residue poisons in commodities going through the international market, including cocoa. If for any reason the residual levels in any commodity exceed the Codex levels, that particular commodity could be rejected by the importing country. Secondly, the accumulation of any chemicals in the cocoa fat may change the taste of the beans and eventually that of the chocolate made from them. This is known as tainting. It is therefore, the task of entomologists to ensure that recommended chemicals do not leave any residues, and that the dosage is the minimum that would give the optimum control under

In Ghana, significant gains have been made in the control of pests and diseases of the cocoa industry through the nationwide use of pesticides under government sponsorship and supervision. The growing global concerns about the effects of the increasing use of agricultural chemicals on farmers, consumers of agricultural produce and the ecology require a re-examination of the issues related to their application in the cocoa industry. This chapter examines the use and the impact of pesticides in cocoa production in Ghana - where data has been accumulated - as a representative country of the industry. The potential ecological impacts of chemicals in the cocoa industry are analyzed, using the modern tool of life-cycle assessment (Ntiamoah and Afrane, 2009). Life-cycle assessment, LCA, has gained such prominence in the environmental management discipline that the International Standards Organization has developed standards for its implementation (ISO 14040-14043, 1997-2000b). This particular analysis is based on primary farm-level data collected from a nationally representative sample of cocoa farmers, published data, results from research

In Ghana, cocoa has played an important role in the economy of the country for over one century. Although the crop was believed to have been brought to the colonial Gold Coast as Ghana was then known - from Fernando Po, an island in the Gulf of Guinea, off the coast of Gabon, in 1879 and from Sao Tome in 1886, records show that in 1891, only twelve years after it first arrived here, cocoa was being exported as a cash crop (Acquaah, 1999, Adjinah and Opoku, 2010). From the 1910/1911 season, Ghana became the leading cocoa producer in the world, a position it held until 1977, when it was overtaken by the Ivory Coast. The country went from being the number one cocoa producer to a period in the early 80s when, as a result of drought, bushfires, low producer prices, diseases and general economic malaise, Ghana fell to the twelfth position and produced less than 160,000 metric tonnes in

Cocoa became attractive as a cash crop in Ghana because of the lower cost involved in its cultivation, compared to a popular crop like palm, as well as the favourable natural conditions that existed in the forest belts. Cocoa could be grown along with other crops and

substances that have been used in the supply chain.

the agricultural conditions in the country.

institutions, the Ghana Cocoa Board and other relevant sources.

**2. The Ghanaian cocoa industry in brief** 

the 1983/1984 season (Adjinah and Opoku, 2010).

Although serious attempts have been made to process them locally, the majority of cocoa beans produced in the country are still exported. Government put a policy in place to process at least 50% by the end of the last decade. The enabling conditions created in free zone enclaves, led to the attraction of private foreign processing companies and the expansion of state-owned facilities. According to data from International Cocoa Organization, ICCO, 200,000 metric tonnes of cocoa grindings were achieved in Ghana in the 2009/2010 season. Compared to the production figure given in Table 1 for the same season, this constitutes about 32% of the beans produced. This means the government's target for grindings was not achieved.

In spite of their peripheral role in the standard household menu - mainly as a dessert or snack, food products made from cocoa go through a long line of operations not normally found with other processed foods, as depicted in Figure 1 (Awua, 2002). Ripe cocoa pods are plucked from the trees and gathered together on clearings in the cocoa farms. After about ten days, all available hands, young and old, gather together to assist in the splitting of the pods and removal of the beans with their hands. (According to Owusu-Manu (1977), this could be a critical stage in the contamination process, with pesticides getting transferred from the workers to the wet beans.) The wet beans are collected together in a heap and covered with plantain leaves and plastic sheets for fermentation. After fermentation, the beans are dried in the sun on bamboo mats to a desired moisture content of around 7.5%.

After dried cocoa beans have been received at the processing plant, they are inspected and thoroughly cleaned of all extraneous matter, such as sticks, stones, metal fragments, dust, loose shells, small fragments and clumps of cocoa beans. The cleaning process consists of a series of operations involving sieves, brushes, airlifts and magnetic separators to remove the

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 55

unwanted materials. The cleansed cocoa beans are roasted at temperatures between 90- 170oC, using a petroleum-based fuel or electricity. This process is needed to develop the chocolate flavour, reduce the moisture content further, and loosen the shells for subsequent removal. The nibs (cotyledons) become friable and generally darker in colour in the process. At the next stage, the shells are separated from the nibs in a process known as winnowing. Winnowing machines use a multi-layered sieve frame with meshes of different sizes, one above the other, with the largest mesh on top. The roasted and crushed beans are ground into a paste known as cocoa liquor or cocoa masse. The grinding process is achieved in two or three stages, using a combination of mills. The cocoa liquor obtained is heat-treated in storage tanks at temperatures of between 90-100oC for aging and microbial destruction. The cocoa paste could be pressed in a hydraulic device to extract cocoa butter. The cake released after pressing is passed through kibbling machines, which break them into smaller pieces, and are packed into four-ply multi-walled paper sacks lined with polyethylene. These are ready for sale and shipment as kibbled cake. The cocoa butter, on the other hand, may be mixed with the other ingredients of chocolate, namely, butter, sugar, milk and emulsifiers. The chocolate mix is subjected to additional processes known as conching and tempering. Conching removes residual moisture, while tempering transforms the thick semi-liquid mix into a solid product through heat treatment. After this process the chocolate is poured into moulds of different shapes and then packaged for the market. Knowledge of the material and energy requirements of each of the processes as shown in figure 1 is necessary to perform the LCA analysis needed to determine the environments impacts.

While the soporific effect of cocoa drinks is widely known, recent research activities have unearthed additional more important health benefits which have enhanced further the attractiveness of cocoa products generally. There are three types of chocolate: dark, milk and white chocolates. Most of the benefits of chocolate consumption are associated with the dark brand. In the last decade, studies have shown that chocolate consumption can play an important role in the reduction of risks or delaying the development of cardiovascular diseases, cancer and other age-related diseases. It has also been linked positively to anticarcinogenic activity in human cells, hypertension, diabetes and sexual weakness. It's newly found reputation as an aphrodisiac, stems from the ability of its sweet and fatty nature to simulate the hypothalamus, which induces pleasure sensation and affects the level of

Cocoa products contain flavonoids and amino acids, and these have been cited as the source of its beneficial effects, while carbohydrates, theobromine and lead have been mentioned as responsible for the negative effects. The flavonoids belong to a large and complex group of compounds called polyphenols and are found in plant products, mainly fruits and vegetables. The phenols in cocoa products have been associated with antioxidant properties, reduction in migraine, protection of arteries from plaque formation and prevention of LDL formation two hours after consuming dark chocolate and perceptible lowering of blood pressure. Some studies have also linked chocolate consumption to muscle recovery and delayed brain function decline (Reuters, 2007). Protein is broken down in the body to form twenty amino acids needed by the body. Eight of these are called essential, which means they are not made by the human body itself and must be supplied from outside. Fourteen of the twenty amino acids found in the body, including the eight essential ones, have been

**2.2 The place of cocoa in the food chain** 

serotonin in the brain (Afoakwa, 2008).

Fig. 1. Process Flowchart for Chocolate Production

unwanted materials. The cleansed cocoa beans are roasted at temperatures between 90- 170oC, using a petroleum-based fuel or electricity. This process is needed to develop the chocolate flavour, reduce the moisture content further, and loosen the shells for subsequent removal. The nibs (cotyledons) become friable and generally darker in colour in the process. At the next stage, the shells are separated from the nibs in a process known as winnowing. Winnowing machines use a multi-layered sieve frame with meshes of different sizes, one above the other, with the largest mesh on top. The roasted and crushed beans are ground into a paste known as cocoa liquor or cocoa masse. The grinding process is achieved in two or three stages, using a combination of mills. The cocoa liquor obtained is heat-treated in storage tanks at temperatures of between 90-100oC for aging and microbial destruction.

The cocoa paste could be pressed in a hydraulic device to extract cocoa butter. The cake released after pressing is passed through kibbling machines, which break them into smaller pieces, and are packed into four-ply multi-walled paper sacks lined with polyethylene. These are ready for sale and shipment as kibbled cake. The cocoa butter, on the other hand, may be mixed with the other ingredients of chocolate, namely, butter, sugar, milk and emulsifiers. The chocolate mix is subjected to additional processes known as conching and tempering. Conching removes residual moisture, while tempering transforms the thick semi-liquid mix into a solid product through heat treatment. After this process the chocolate is poured into moulds of different shapes and then packaged for the market. Knowledge of the material and energy requirements of each of the processes as shown in figure 1 is necessary to perform the LCA analysis needed to determine the environments impacts.

#### **2.2 The place of cocoa in the food chain**

54 Pesticides in the Modern World - Risks and Benefits

Cocoa production

Fermentation and Drying

Jute bag Manufacturing

Jute plant cultivation

Sugar production

Paper box packaging

Sugar beet cultivation

Fertilizer production

Pesticides production

Milk production

production

Fig. 1. Process Flowchart for Chocolate Production

PE production

Cattle Raising

Bagging and Storage

Industrial cleaning of beans

Roasting

Winnowing

Grinding

Mixing of cocoa liquor, milk, sugar and other ingredients

Conching and Refining

production Film packaging

Tempering and Moulding

Chocolate packaging

Distribution and Retail

Consumption phase

Expired food & packaging disposal While the soporific effect of cocoa drinks is widely known, recent research activities have unearthed additional more important health benefits which have enhanced further the attractiveness of cocoa products generally. There are three types of chocolate: dark, milk and white chocolates. Most of the benefits of chocolate consumption are associated with the dark brand. In the last decade, studies have shown that chocolate consumption can play an important role in the reduction of risks or delaying the development of cardiovascular diseases, cancer and other age-related diseases. It has also been linked positively to anticarcinogenic activity in human cells, hypertension, diabetes and sexual weakness. It's newly found reputation as an aphrodisiac, stems from the ability of its sweet and fatty nature to simulate the hypothalamus, which induces pleasure sensation and affects the level of serotonin in the brain (Afoakwa, 2008).

Cocoa products contain flavonoids and amino acids, and these have been cited as the source of its beneficial effects, while carbohydrates, theobromine and lead have been mentioned as responsible for the negative effects. The flavonoids belong to a large and complex group of compounds called polyphenols and are found in plant products, mainly fruits and vegetables. The phenols in cocoa products have been associated with antioxidant properties, reduction in migraine, protection of arteries from plaque formation and prevention of LDL formation two hours after consuming dark chocolate and perceptible lowering of blood pressure. Some studies have also linked chocolate consumption to muscle recovery and delayed brain function decline (Reuters, 2007). Protein is broken down in the body to form twenty amino acids needed by the body. Eight of these are called essential, which means they are not made by the human body itself and must be supplied from outside. Fourteen of the twenty amino acids found in the body, including the eight essential ones, have been

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 57

**(Causal agent) Symptoms** 

tips

growth

trunks. Soil is affected

often with perforated centers

cream-coloured mycelium

underneath bark and roots

Part of branch withers

are shed prematurely

white mycelial threads

malformed

are small

Throughout the 90's, the tonnage of cocoa produced annually rarely exceeded 400,000 metric tonnes. This situation was attributed to a variety of causes, although the prevalence of pests and cocoa diseases was seen as the main reason. Crop losses due to mirids alone

Pod rots, go brownish-black. Beans destroyed in immature pods. Could result in die-back

Leaves fall prematurely and die-back of twigs occurs. Fungus fruit bodies on root and dead

Leaves show bands of transparent lesions

Longitudinal cracking of trunk from ground level to about 1.2m upwards, fills with

Defoliation and death of plants. White fanshaped patches of mycelium are produced

Excessive production of buds at the nodes

Leaves turn yellow and fall prematurely. Smaller branches wither starting from the

Network of black threads which spread throughout the canopy, smothers shoots

Pods turn brown, becomes encrusted with white to pinkish mealy growth of the fungus

Parasitic flowering plant on host branches.

Reddish patches on leaves and twigs; leaves

Premature defoliation, death of twigs, pods

Leaves are covered and killed in a network of

Appears as brown necrotic areas with concentric rings of black spots. Pods are later

Swelling of chupons and twigs; leaves develop yellow patterns, get crinkled and

covered with black sooty powder

**Disease Type of Infection** 

(*Phytophthora spp.*)

(Cocoa necrosis virus)

(*Calonectria rigidiuscula*)

(*Oncobasidium theobroma*)

*(Marasmius equicrinis)* 

(*Trachysphaera fructigena*)

(*Tapinanthus bangwensis*)

(*Cephaleuros mycoidea*)

(Cocoa swollen shoot

(*Marasmius scandens*)

**3.1 National cocoa pests and diseases control programme** 

(*Fomes lignosus*)

(*Botryodiphlodia theobromae*)

virus)

Fungus

Table 1. Diseases of Cocoa in Ghana

(*Armillaria mellea*)

(*Ustulina zonata*)

Fungus

Fungus

(*Fomes noxius*)

Black pod Fungus

Brown root rot Fungus

Cocoa necrosis Virus

Collar crack Fungus

Collar rot Fungus

Cushion gall Fungus

Mealy pod Fungus

Pod rot Fungus

Red rust Alga

Swollen shoot Virus

White Root Fungus

White thread Blight

Source: Offei *et al*. (2005)

Mistletoe Flowering Plant

Vascular Streak Die-back

Horse hair blight

found in cocoa. In addition to building cells and repairing tissues, amino acids also have antioxidant properties, and they form antibodies to combat invading bacteria and viruses (Awuah, 2002).

While international standards are such that the pesticides used in the field can hardly find their way into chocolate, a number of documented negative effects have been associated with some of the natural and absorbed constituents of cocoa. Perhaps the major one is obesity. It is believed that the amounts of dark chocolate that needs to be consumed in order to experience the good benefits of the product could lead to obesity and its resultant negative effects. Although it is not supported by scientific studies, it is also believed that chocolate consumption can lead to acne (*www.chocolate.gourmetrecipe.com*). The heavy metal, lead, is known to maintain a high solubility in chocolate, and this may lead to lead poisoning (Rankin *et al*, 2005). Chocolate is also known to be toxic to some animals like horses, dogs, parrots, cats and small rodents, because they are unable to metabolize the theobromine which is found in chocolate (Drolet *et al*, 1984; Blakemore and Shearer, 1943).

#### **3. Pests and diseases of cocoa**

The increasing world population cannot be sustained without the use of pesticides in food production. Their usage therefore benefits not only farmers but also consumers. Pesticides are used to reduce food losses not only during production, but also during the post-harvest storage stage (Moy and Wessel, 2000). The general pest control strategy is for the intervention to destroy the pests feasting on the crops, but at the same time not to damage the produce so much as to render them unhealthy or unprofitable. This means looking for the thin line which separates good practices from bad. Good agricultural practice (GAP) requires good timing and proper application. The crops are sprayed on the advice of specialists at an opportune time in the reproductive cycle of the pest, when the highest numbers could be eliminated. Also in order to maintain the activities of friendly insects the area of application of the insecticides should be clearly delineated.

The cocoa tree and its pod can be attacked by different species of insects, fungal diseases and rodents (Entwistle, 1972). The major diseases affecting cocoa in Ghana are given in Table 1. The most important of these are *Phytophthora* pod rot, commonly called "black pod", and locally known as '*akate*'; and the swollen shoot virus, also known locally as '*cocoa sasabro*'. The black pod rot, a fungal disease which appears as characteristic brown necrotic lesions on the pod's surface and as rotting of the beans, does the most damage to cocoa. An estimated 30% of annual cocoa production is lost to it, especially during years of high rainfall. At 2005 cocoa bean prices this is an estimated US\$1.5 billion in lost revenue (www.icco.org). Other estimates put the loss specifically at 450 thousand metric tonnes annually, while 250, 200 and 50 thousand MT are lost to witches' broom, capsids, and the swollen shoot virus (CSSV), respectively (*www.dropdata.org*). Witches' broom and frosty pod rot are predominant in Latin America, while the black pod and CSSV are common in West Africa. These diseases are counted by breeding disease-resistance species, sanitation and the use of fungicides (Bastos, 1996; Opoku *et al*, 2007).

Most insects which attack cocoa are of the bug or *miridiae* family. This is a large family of insects of which capsids, the most well-known, have achieved their notoriety from the degree of havoc they can wreck on cash crops like cocoa. They feed on plants by piercing the tissue and sucking their juices. Capsids are small, terrestrial insects, usually oval-shaped or elongate and measuring less than 12 mm. They were identified as pests at the turn of the last century and are the main insects that feed on cocoa in Africa (Mahot et al., 2005).


Source: Offei *et al*. (2005)

56 Pesticides in the Modern World - Risks and Benefits

found in cocoa. In addition to building cells and repairing tissues, amino acids also have antioxidant properties, and they form antibodies to combat invading bacteria and viruses

While international standards are such that the pesticides used in the field can hardly find their way into chocolate, a number of documented negative effects have been associated with some of the natural and absorbed constituents of cocoa. Perhaps the major one is obesity. It is believed that the amounts of dark chocolate that needs to be consumed in order to experience the good benefits of the product could lead to obesity and its resultant negative effects. Although it is not supported by scientific studies, it is also believed that chocolate consumption can lead to acne (*www.chocolate.gourmetrecipe.com*). The heavy metal, lead, is known to maintain a high solubility in chocolate, and this may lead to lead poisoning (Rankin *et al*, 2005). Chocolate is also known to be toxic to some animals like horses, dogs, parrots, cats and small rodents, because they are unable to metabolize the theobromine which is found in chocolate (Drolet *et al*, 1984; Blakemore and Shearer, 1943).

The increasing world population cannot be sustained without the use of pesticides in food production. Their usage therefore benefits not only farmers but also consumers. Pesticides are used to reduce food losses not only during production, but also during the post-harvest storage stage (Moy and Wessel, 2000). The general pest control strategy is for the intervention to destroy the pests feasting on the crops, but at the same time not to damage the produce so much as to render them unhealthy or unprofitable. This means looking for the thin line which separates good practices from bad. Good agricultural practice (GAP) requires good timing and proper application. The crops are sprayed on the advice of specialists at an opportune time in the reproductive cycle of the pest, when the highest numbers could be eliminated. Also in order to maintain the activities of friendly insects the

The cocoa tree and its pod can be attacked by different species of insects, fungal diseases and rodents (Entwistle, 1972). The major diseases affecting cocoa in Ghana are given in Table 1. The most important of these are *Phytophthora* pod rot, commonly called "black pod", and locally known as '*akate*'; and the swollen shoot virus, also known locally as '*cocoa sasabro*'. The black pod rot, a fungal disease which appears as characteristic brown necrotic lesions on the pod's surface and as rotting of the beans, does the most damage to cocoa. An estimated 30% of annual cocoa production is lost to it, especially during years of high rainfall. At 2005 cocoa bean prices this is an estimated US\$1.5 billion in lost revenue (www.icco.org). Other estimates put the loss specifically at 450 thousand metric tonnes annually, while 250, 200 and 50 thousand MT are lost to witches' broom, capsids, and the swollen shoot virus (CSSV), respectively (*www.dropdata.org*). Witches' broom and frosty pod rot are predominant in Latin America, while the black pod and CSSV are common in West Africa. These diseases are counted by breeding disease-resistance species, sanitation and the

Most insects which attack cocoa are of the bug or *miridiae* family. This is a large family of insects of which capsids, the most well-known, have achieved their notoriety from the degree of havoc they can wreck on cash crops like cocoa. They feed on plants by piercing the tissue and sucking their juices. Capsids are small, terrestrial insects, usually oval-shaped or elongate and measuring less than 12 mm. They were identified as pests at the turn of the last

century and are the main insects that feed on cocoa in Africa (Mahot et al., 2005).

area of application of the insecticides should be clearly delineated.

use of fungicides (Bastos, 1996; Opoku *et al*, 2007).

(Awuah, 2002).

**3. Pests and diseases of cocoa** 

Table 1. Diseases of Cocoa in Ghana

#### **3.1 National cocoa pests and diseases control programme**

Throughout the 90's, the tonnage of cocoa produced annually rarely exceeded 400,000 metric tonnes. This situation was attributed to a variety of causes, although the prevalence of pests and cocoa diseases was seen as the main reason. Crop losses due to mirids alone

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 59

were direct beneficiaries of the exercise, were themselves responsible for the sanitation practices, i.e. brushing, pruning, shade management and removal of diseased pods from the farms. They also provided water for spraying and were expected to monitor the activities of the sprayers on the farm. The spraying is carefully done using a portable petrol-enginedriven knapsack mist-blowers, which combines the idea of low-volume application of

As a result of this initiative, between the period 2002-2004, nearly 600,000 ha involving about 360,942 farms and 330,121 individual farmers, were sprayed three times each season against the black pod diseases, while an estimated 826,141 ha involving 470,801 and 446,593 farmers were sprayed twice each season in the mirids control exercise. From the 2001/2002 season when beans output of 380,000 metric tons was recorded, production jumped to about 500,000 metric tonnes in the 2002/2003 season and almost doubled in the 2003/2004 season

Started ten years ago, the mass spraying exercise has now become a permanent fixture in all the 72 geographical districts in the cocoa-growing areas with the following breakdown: 21districts for black pod spraying only, 35 districts for mirids only, and 16 for both programmes. District Task Forces (DTF) and Local Task Forces (LTF), have been formed in each operational district and local area, respectively. The DTF manages the project at the district level and is in charge of gang recruitment, storage, distribution of inputs and logistics and general supervision. The LTF on the other hand, handles project management at the village level and is responsible for the planning and execution of the programmes at that level. Table 3 gives the seasonal cocoa production figures along with the amounts of fertilizers and pesticides which have been used in Ghana in recent years. The table indicates clearly that cocoa production has increased significantly in the last decade, but it has been at the expense of more pesticides and fertilizers. Data obtained from COCOBOD indicate that fourteen different kinds of insecticides and fungicides have been used for spraying farms since the start of the mass spraying exercise. Even with the limited data provided, the increase in pesticide usage per unit weight of cocoa over the period is evident. The same trend applies to fertilizer usage. Serious attention must be paid to these trends beyond the normal concerns with maximum residue limits (MRLs) which international traders focus on. The impact of these prodigious amounts of chemicals used in cocoa production on the environment as a whole can

Pesticides Usage*<sup>a</sup>*

Fungicides (MT)

Fertilizer used per MT

Fungicides used per MT

Insecticides (liters)

2004/05 601.9 - 1023.6 1120.0 - 1.86 2005/06 740.4 - 745.0 759.4 - 1.03 2006/07 614.5 70.1 590.0 1120.0 0.11 1.83 2007/08 729.0† 55.8 1020.0 1290.0 0.08 1.77 2008/09 662.0† 105.0 1760.0 1800.0 0.16 2.72 2009/10 632.0† 130.0 2300.0 1997.7 0.20 3.16 *†Source: ICCO Quarterly Bulletin of Cocoa Statistics, Vol. XXXVI, No. 4, Cocoa year 2009/2010. Published: 30- 11-2010; all others in this column from, The State of the Ghanaian Economy, 2007. a Source: COCOBOD, Ghana.*  Table 3. Seasonal Cocoa Production, Fertilizer and Insecticide Usage in Ghana, 2004-2010

sprays with the principle of using fan-driven air to carry the spray up into the trees.

be determined through life-cycle analyses (Ntiamoah and Afrane, 2009).

Total*<sup>a</sup>* Fertilizer Used (106 kg)

to an all-time high of over 736,000 metric tonnes.

Crop Season

Cocoa Production (106 kg)

were estimated at between 25-35% per annum. To reverse this trend, the government of Ghana in the year 2000 introduced the national Cocoa Diseases and Pests Control Programme, CODAPEC, popularly known as "mass spraying", to combat the resurgence of mirids and black pod diseases on cocoa farms. This opportunity was also to be used to train farmers and technical personnel in the scientific methods of pests and diseases control (Adjinah and Opoku, 2010). Participants were trained in the dosage of the various pesticides, dangers of exposure to pesticides, importance of the use of protective clothing, observance of personal hygiene, environmental safety issues, first-aid, techniques of application and handling and disposal of empty containers. Lessons were given through radio programmes, town meetings and 'training-of-trainers' workshops. Table 2 gives the brands of pesticides, approved by the Cocoa Research Institute of Ghana (CRIG), which are currently in use on Ghanaian cocoa farms under the CODAPEC programme and their application frequency.


Table 2. Pesticides approved for used in the control of mirids and black pod disease under the CODAPEC programme

The black pod control programme covered all cocoa-growing districts in the Volta, Brong Ahafo and parts of Western, Ashanti and Eastern Regions. Spraying against mirids, on the other hand, covered the Central, Eastern and parts of Western and Ashanti Regions. Spraying gangs were established at each spraying centre. A gang of ten (for black pod control) and six (for mirids control) had a supervisor each responsible for the general execution of the programme at the unit level. One mechanic was attached to a group of 20 gangs to oversee the maintenance and repairs of the spraying machines. The farmers, who

were estimated at between 25-35% per annum. To reverse this trend, the government of Ghana in the year 2000 introduced the national Cocoa Diseases and Pests Control Programme, CODAPEC, popularly known as "mass spraying", to combat the resurgence of mirids and black pod diseases on cocoa farms. This opportunity was also to be used to train farmers and technical personnel in the scientific methods of pests and diseases control (Adjinah and Opoku, 2010). Participants were trained in the dosage of the various pesticides, dangers of exposure to pesticides, importance of the use of protective clothing, observance of personal hygiene, environmental safety issues, first-aid, techniques of application and handling and disposal of empty containers. Lessons were given through radio programmes, town meetings and 'training-of-trainers' workshops. Table 2 gives the brands of pesticides, approved by the Cocoa Research Institute of Ghana (CRIG), which are currently in use on Ghanaian cocoa farms under the CODAPEC programme and their

**application Frequency** 

3 times during each cocoa season

Twice during each cocoa season

Knapsack sprayer

Knapsack sprayer

**Pesticide used Active ingredient Method of** 

12% metalaxyl, 60% Cuprous oxide

Cuprous hydroxide

Cupric hydroxide Cupric hydroxide +

Cuprous oxide + metalaxyl

Table 2. Pesticides approved for used in the control of mirids and black pod disease under

The black pod control programme covered all cocoa-growing districts in the Volta, Brong Ahafo and parts of Western, Ashanti and Eastern Regions. Spraying against mirids, on the other hand, covered the Central, Eastern and parts of Western and Ashanti Regions. Spraying gangs were established at each spraying centre. A gang of ten (for black pod control) and six (for mirids control) had a supervisor each responsible for the general execution of the programme at the unit level. One mechanic was attached to a group of 20 gangs to oversee the maintenance and repairs of the spraying machines. The farmers, who

metalaxyl

Bifenthrin Thiamethoxam

Cocostar 210 EC Bifenthrin + Pirimiphosmethyl

Confidor 200SL Imidacloprid Carbamult Promecarb

the CODAPEC programme

application frequency.

Nordox 75 WP 86% Cuprous oxide, 14% inert

Champion WP 77% cupric hydroxide

*Fungicides* 

WP

WP

WP

*Insecticides*  Akatemaster Actara

Ridomil 72 plus

Funguran OH

Kocide 101 WP Fungikill WP Metalm 72 Plus were direct beneficiaries of the exercise, were themselves responsible for the sanitation practices, i.e. brushing, pruning, shade management and removal of diseased pods from the farms. They also provided water for spraying and were expected to monitor the activities of the sprayers on the farm. The spraying is carefully done using a portable petrol-enginedriven knapsack mist-blowers, which combines the idea of low-volume application of sprays with the principle of using fan-driven air to carry the spray up into the trees.

As a result of this initiative, between the period 2002-2004, nearly 600,000 ha involving about 360,942 farms and 330,121 individual farmers, were sprayed three times each season against the black pod diseases, while an estimated 826,141 ha involving 470,801 and 446,593 farmers were sprayed twice each season in the mirids control exercise. From the 2001/2002 season when beans output of 380,000 metric tons was recorded, production jumped to about 500,000 metric tonnes in the 2002/2003 season and almost doubled in the 2003/2004 season to an all-time high of over 736,000 metric tonnes.

Started ten years ago, the mass spraying exercise has now become a permanent fixture in all the 72 geographical districts in the cocoa-growing areas with the following breakdown: 21districts for black pod spraying only, 35 districts for mirids only, and 16 for both programmes. District Task Forces (DTF) and Local Task Forces (LTF), have been formed in each operational district and local area, respectively. The DTF manages the project at the district level and is in charge of gang recruitment, storage, distribution of inputs and logistics and general supervision. The LTF on the other hand, handles project management at the village level and is responsible for the planning and execution of the programmes at that level. Table 3 gives the seasonal cocoa production figures along with the amounts of fertilizers and pesticides which have been used in Ghana in recent years. The table indicates clearly that cocoa production has increased significantly in the last decade, but it has been at the expense of more pesticides and fertilizers. Data obtained from COCOBOD indicate that fourteen different kinds of insecticides and fungicides have been used for spraying farms since the start of the mass spraying exercise. Even with the limited data provided, the increase in pesticide usage per unit weight of cocoa over the period is evident. The same trend applies to fertilizer usage. Serious attention must be paid to these trends beyond the normal concerns with maximum residue limits (MRLs) which international traders focus on. The impact of these prodigious amounts of chemicals used in cocoa production on the environment as a whole can be determined through life-cycle analyses (Ntiamoah and Afrane, 2009).


*<sup>†</sup>Source: ICCO Quarterly Bulletin of Cocoa Statistics, Vol. XXXVI, No. 4, Cocoa year 2009/2010. Published: 30- 11-2010; all others in this column from, The State of the Ghanaian Economy, 2007. a Source: COCOBOD, Ghana.* 

Table 3. Seasonal Cocoa Production, Fertilizer and Insecticide Usage in Ghana, 2004-2010

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 61

From the point of view of COCOBOD, the implementers of the programe, the mass spraying exercise has been a roaring success, because of the increased yield it has generated, the renewed enthusiasm for cocoa cultivation that it has awoken in farmers, and also because of the 60,000 direct jobs it has created for sprayers, supervisors and mechanics in the rural areas of the country (Adjinah and Opoku, 2010). According to the Seed Production Unit of COCOBOD, demand for planting materials has gone up significantly because new farms are been established and old ones rejuvenated (Adjinah and Opoku, 2010). Farmers now clearly see cocoa farming as a profitable venture, especially with the continued reduction in

**5. Potential ecological impacts of pesticides use in cocoa production** 

The Society of Environmental Toxicology and Chemistry (SETAC), defines LCA as:

distribution; use, re-use, maintenance; recycling, and disposal" (Consoli *et al*, 1993).

input to the definition of LCA. According to ISO 14040 (1997), LCA is

Goal and scope definition

> Inventory analysis

Impact Assessment

Fig. 2. Components of a Life Cycle Assessment (ISO 14040)

A proper assessment of the effect of pesticides and other chemicals used during cocoa production and processing on the environment and human health, has to begin with an effective quantification of the chemicals released into the environment and their impact on various aspects of human life and the environment. For this purpose, one of the widely accepted modern methods for examining the environmental impacts associated with a

"an objective process to evaluate the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment; to assess the impact of those energy and material uses and releases to the environment; and to identify and evaluate opportunities to effect environmental improvements. The assessment includes the entire life cycle of a product, process or activity, encompassing extracting and processing raw materials; manufacturing, transportation and

The International Organization for Standardization (ISO) has also provided very relevant

"a compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle. A product system is a collection of materially or energetically connected unit processes, which performs one or more defined functions".

Interpretation

inflation and the general improvement in the economy.

service or a product is the life cycle assessment (LCA) technique.

**5.1 Life cycle assessment methodology** 

While non-chemical means of managing cocoa pests and diseases are widely recommended, the need for agro-chemicals to manage cocoa pests and diseases is unavoidable and will continue for years to come. However, the effects of continued exposure of users of pesticides, environmental risks, issues of pest resistance and possible hazards for consumers require a re-examination of the benefits of pesticide application and the risks involved. Hence the introduction of Good Agricultural Practices (GAP) to considerably mitigate, if not eliminate, the problems associated with the excessive and unnecessary application of pesticides. High residue levels and tainting of the beans could lead to their rejection on the international market. Testing for residues is carried out following internationally agreed and validated methods (Moy and Wessel, 2000). Though some insecticide residues are sometimes found in the shells, they are hardly found in the nib which is used in chocolate manufacture.
