Highlights AGRONOMY OF CACAO.docx

**AGRONOMY OF CACAO** The scientific name of cacao is *Theobroma cacao.* Cacao was named by the 18th Century botanist, Carolus Linnaeus. The Centre of origin or genetic diversity of cacao is the Amazon basin, South America. The word 'cacao' refers to the tree while 'cocoa' refers to dried bean of c...

**AGRONOMY OF CACAO** The scientific name of cacao is *Theobroma cacao.* Cacao was named by the 18th Century botanist, Carolus Linnaeus. The Centre of origin or genetic diversity of cacao is the Amazon basin, South America. The word 'cacao' refers to the tree while 'cocoa' refers to dried bean of cacao or a drink made from its seeds. Cacao belongs to the genus Theobroma, a member of the family Sterculiaceae. More than 22 species are listed, but only one, the Theobroma cacao or \'food of the gods\', is produced for commercial use. Other members of cacao family are *Theobroma bicolor* and *Theobroma augustifolium*. Cacao has 20 chromosomes. Ideally it grows in tropical regions, along a band located 20° to the north and south of the equator. Nearly 70% of the world crop today is grown in West Africa. Cacao was introduced to Nigeria from Fernando Po by Chief Squiss Ibaningo in 1874. Cocoa Research Institute of Nigeria (CRIN) is responsible for breeding, research and development of cacao in Nigeria. Spanish introduced cacao into the West Indies and the Philippines. Cacao was also introduced into the rest of Asia, South Asia and into West Africa by Europeans. Cacao was introduced to Ghana by Tetteh Quarshie in 1874. Cacao is one of the world's most valuable crops, cultivated worldwide on 8.2 million hectares, grown in 58 countries, and worth over US\$4 billion annually. As of November 2018, evidence suggests that cacao was first domesticated in equatorial South America, before being domesticated in Central America roughly 1,500 years later. Côte d'Ivoire is the single largest producer of cocoa beans, accounting for approximately 31% of the world's supply. Other leading cocoa farming countries include Brazil, Cameroon, Ghana, Indonesia, and Nigeria. See the 2020 cocoa production from leading six countries below, Nigeria is the 4^th^ largest producer of cocoa. Cote D've. Ghana, Indonesia, Nigeria, Ecuador, cameroon +-----------------------------------+-----------------------------------+ | **Cocoa bean production, 2020** | | +===================================+===================================+ | **Country** | **Weight ([tonnes])** | +-----------------------------------+-----------------------------------+ | - Côte d'Ivoire | 2,180,000 | +-----------------------------------+-----------------------------------+ | https://upload.wikimedia.org/wiki | 811,700 | | pedia/commons/thumb/1/19/Flag\_of | | | \_Ghana.svg/23px-Flag\_of\_Ghana. | | | svg.png [[Ghana]](htt | | | ps://en.wikipedia.org/wiki/Ghana) | | +-----------------------------------+-----------------------------------+ |  [[Indonesia]](htt | | | ps://en.wikipedia.org/wiki/Indone | | | sia) | | +-----------------------------------+-----------------------------------+ | https://upload.wikimedia.org/wiki | 350,146 | | pedia/commons/thumb/7/79/Flag\_of | | | \_Nigeria.svg/23px-Flag\_of\_Nige | | | ria.svg.png [[Nigeria]{.underline | | | }](https://en.wikipedia.org/wiki/ | | | Nigeria) | | +-----------------------------------+-----------------------------------+ |   | | | [[Ecuador]](https://e | | | n.wikipedia.org/wiki/Ecuador) | | +-----------------------------------+-----------------------------------+ | https://upload.wikimedia.org/wiki | 280,000 | | pedia/commons/thumb/4/4f/Flag\_of | | | \_Cameroon.svg/23px-Flag\_of\_Cam | | | eroon.svg.png [[Cameroon]{.underl | | | ine}](https://en.wikipedia.org/wi | | | ki/Cameroon) | | +-----------------------------------+-----------------------------------+ | Total | 5,596,397 | +-----------------------------------+-----------------------------------+ **Uses of cacao** 1. Cacao is an important Neotropical, perennial crop, on which the thriving global chocolate industry is based. 2. Economic cacao cultivars are grown for the production of dried beans, which are the source of cocoa liquor, cocoa butter, cocoa cake and cocoa powder. 3. Cacao is a fast-growing tropical forest plant suitable for agroforestry 4. Cacao is capable of providing additional goods like timber and firewood, fruits, construction materials, honey, resin, medicine and materials for ritual ceremonies. 5. Peels of cacao fruits are used to make animal feed. **A cup of cocoa a day may keep the doctor away, the reasons are listed below:** 1. Cocoa is rich in polyphenols, which have significant health benefits, including reduced inflammation and improved cholesterol levels. However, processing cocoa into chocolate or other products can substantially decrease the polyphenol content. 2. Studies reveal that cocoa is rich in flavanols, which lower blood pressure by improving nitric oxide levels and blood vessel function. Cocoa containing between 30--1,218 mg of flavanols can reduce blood pressure by an average of 2 mmHg. 3. Cocoa can improve blood flow and reduce cholesterol. Eating up to one serving of chocolate per day may reduce your risk of heart attack, heart failure and stroke. 4. Flavanols in cocoa can support neuron production, brain function and improve blood flow and supply to brain tissue. They may have a role in preventing age-related brain degeneration, such as in Alzheimer's disease, but more research is needed. 5. Cocoa may exert some positive effects on mood and symptoms of depression by reducing stress levels and improving calmness, contentment and overall psychological well-being. However, more research is needed. 6. Cocoa and dark chocolate may reduce your risk of diabetes and maintain healthy blood sugar levels. However, there are some conflicting results in the scientific evidence, so more research is needed. 7. Cocoa products are associated with a lower weight, and the addition of cocoa to your diet may help achieve faster weight loss. However, more research is needed on this topic to determine exactly what type and how much cocoa is ideal. The flavanols in cocoa have been shown to have promising anti-cancer properties in test-tube and animal studies, but data from human trials is lacking. 8. Cocoa extract has demonstrated some anti-asthmatic properties in animal studies. However, human trials are needed before it can be recommended as a treatment. 9. Cocoa can promote healthy teeth by fighting bacteria that cause cavities, though this does not apply to sugar-containing products. It also promotes healthy skin by protecting it from sunlight and improving circulation, the skin surface and hydration. **Meaning of some terms in Cacao agronomy** [Cauliflorous] -- attachment of flowers to stem [Semi-deciduous] -- half evergreen [Jorquetting] -- formation of branches in a group of five [Dimorphism] -- two forms [Chupons] - vertical branches [Fans] -- lateral branches [Cherelle] -- young cacao pod [Viviparous germination] - germination in pod attached to tree a. Forastero type (green- immature, yellow- ripe) having medium to large pods of not less than 350 g weight, smooth or shallow furrows on the surface without prominent constriction at the neck can be selected. b. Husk thickness of pods should be less than 1 cm. c. Pod value (number of pods to give 1 kg wet beans) should be less than 12. d. Number of beans per pod has to be more than 35. e. Bean dry weight to be more than 1 g. ------------------------------------------------------------------------------------------------------------------------------------------ **Vegetative propagation** **Rootstock** **Scions** **Success (%)** ---------------------------- --------------------------- --------------------------------------------------------------- ----------------- Budding:\ 10-12 month old seedlings Bud patch of 2.5 cm length and 0.5 cm width from the bud wood 85 Patch budding Grafting:\ 3-4 month old seedlings Scion stick of 12- 15 cm length with 2- 3 buds 70 Soft wood grafting ------------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Main crop** **Spacing**\ **Cocoa as inter crop** **(m)** --------------- -------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Coconut 7.5 x 7.5 One Cocoa row of plants at 3m interval at the center of two Coconut rows and One Cocoa at the center of two Coconut plants along the Coconut row. This layout will hold about 500 plants per hectare Oil palm 4.5 x 4.5 Five cocoa plants would come between four oil plants resulting in 400 plants per hectare. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------- **Age of the plant** **Water requirement**\ **(litre/ plant / day)** ---------------------- -------------------------- 1st year 3-5 2nd  year 10 3rd year and later 20-25 ------------------------------------------------- **Fertilizer (g/ plant)** **I year** **II year** **III year onwards** --------------------------- ------------ ------------- ---------------------- Urea 72 144 220 Rock phosphate 65 130 200 Muriate of Potash 77 154 230 **Method of application** a. Fertilizer may be applied uniformly around the base of the tree up to a radius of 30 cm during the first year, forked and incorporated into the soil. b. For grown up plants the best method is to rake and mix the fertilizers with soil in shallow basins of around 75 cm. This radius may be increased gradually upto 150 cm after third year. Care should be taken not to spill the inorganic fertilizers on the trunk, branches or leaves of young trees in order to avoid burning c. **Drip (Fertigation) -** Fertilizers can be applied through drip irrigation system (fertigation). Weighed quantity of fertilizers as per schedule was dissolved in water and then injected to sub-main through venturi and then to lateral lines as per treatment. Drip irrigation is done once in 2 days. The fertilizers are applied through drip irrigation at weekly intervals. 100:40:140 kg of N, P and K are applied through drip and fertigation in different stages of crop growth as detailed below. -------------------------------------------------------------------------------------------------------------------------------------------------- **Phases of crop** **Months** **Weeks** **No. of weeks** **\*Water soluble fertilizers**\ **(NPK (%))** ---------------------------------------------------------- --------------------- ----------- ------------------ ---------------------------------- 1st season flower initiation January & February 1-8 8 12.5 Fruit set March 9-13 5 10.0 Fruit development April and May 14-22 9 12.5 Fruit maturity, harvest and 2nd season flower initiation June and July 23-30 8 20.0 Fruit set August 31-35 5 12.5 Fruit development September & October 36-43 8 15.0 Fruit maturity and harvest November & December 44-52 9 17.5 Total       100 -------------------------------------------------------------------------------------------------------------------------------------------------- **Pruning and height control** The basic aim of pruning cocoa trees is to encourage a tree structure that allows sunlight to filter through to the main branches and trunk (what is known as a jorquette) to stimulate flowering and facilitate harvesting. Pruning generally takes place twice a year. The first pruning is done after the main harvest (from April to July) and just before the rainy season, and the second pruning five months later, during the months of November and December. Young plants should develop a jorquette at a height of about 1 meter. It has been found that increasing light in-tensity decreases the jorquette-height. If a jorquette is considered too low, it can be cut off. The strongest of the re-growing chupon can be selected and all others removed. In due course, this chupon will produce a jorquette at a higher level. Vegetatively propagated plants generally form a jorquette at ground level. Fan branches should be limited to 3 to 4 to allow more light to enter and decrease the humidity within the canopy. Basal chupons should be removed at regular intervals and all lower branches that form or bend below the jorquette should be trimmed off. Furthermore all branches within 60 cm of the jorquette, all old and diseased branches and branches growing into the centre of the tree canopy should be removed. This should be done at regular intervals through maintenance pruning. All prunings should be left in the field to rot down, except the diseased ones. Diseased or unwanted branches with vascular die- back and water shoots are to be removed to maintain the health and vigour of the tees. It include removing all unnecessary chupons, dead branches, climbing plants, rodents- damaged and over ripe pods. Pruning the trees at 20 % canopy removal will increase the number of flower cushions per tree and number of fruits per tree and it reduces the light transmission (12.72 %) and increases the chlorophyll content (1.961 mg g-1) **Pruning of grafted plants** Pruning of grafted plants is done, after first year of planting, primary pruning should be done to obtain a supporting framework of one or more upward growing main stems. Then drooping or inward growing branches are to be removed. Secondary pruning is suggested to develop well- shaped canopy and desired canopy should be maintained in umbrella shaped form with about 3.8 m to 4.2 m spread and 2.7 m height depending upon the space and main crop in which cocoa is under planted/grown. Pruning is usually done annually in August- September. The proper pruning of cocoa ensures adequate ventilation in garden; maintain tree height, makes spraying and harvesting operations easier. It also prevents damage during the harvesting operation for the companion crop.To prevent the entry of fungi, fungicides are to be applied (Bordeaux paste) immediately after the pruning. Generally pruning is done after harvesting. **Pest management** Pests and diseases are important risk to productivity and quality of harvest which in turn affects the returns to the farmers. Since cocoa is an introduced crop the more important for the farmer is to be clear about the pests and diseases and be able to identify the symptoms correctly. 1\. Mealybugs (*Planococcus lilacinus, Planococcus citri, Paracoccus marginatus and Rastrococcus iceryoides*). It colonizes the tender parts of the plant such as growing tips of the shoots, the terminal buds, the flower cushions, the young cherelles and mature pods. Feeding of mealy bugs induces cherelle wilt. Following control measures are recommended: When the infestation is lesser: Spraying of Neem Oil 3% or fish oil rosin soap 25g/litre. In case of severe incidence, spraying of any one of the following chemicals is recommended : Dimethoate (2 ml/litre) , Profenophos (2 ml/litre), Chlorpyriphos (5 ml/litre), Buprofezin (2 ml/litre), Imidacloprid (0.6 ml/lit), Thiamethoxam (0.6g/litre). In the area where P. marginatus alone occurs, field release of Acerophagus papayae, the encyrtid parasitoid @ 100 per hamlet is recommended as the best biological management strategy. 2\. Aphids (*Toxoptera aurantii and Aphis gossypii*):They colonize on the underside of tender leaves, succulent stem, flower buds and small cherelles. Heavy infestation may occur during hot summer and after rainy season which brings about premature shedding of flowers and curling of leaves. Control measure include spraying of dimethoate @ 2 ml per litre **Diseases of cacao** 1\. Seedling blight: It is cause by a fungus *Phytophthora palmivora*. The symptom develops on the leaves and stem of seedlings or budded plants. On leaves, small water soaked lesions appear which later coalesce in the blighting of leaves. On stem, water soaked lesions develop initially and later turn to black colour. Stem infection develop any point on the stem causing the death of seedlings. It can be controlled by removal and destruction of infected seedlings. Spray with 1 percent Bordeaux mixture or 0.2% copper oxychloride just before the onset of heavy rain and thereafter at frequent intervals. 2\. Black Pod rot: It is cause by *Phytophthora palmivora.* Infection appears as chocolate brown spot, which spreads rapidly and soon occupies the entire surface of the pod. As the disease advances, a whitish growth of fungus consisting of fungal sporangia is produced over the affected pod surface. Ultimately, the affected pods turn brown to black. The internal tissues as well as the beans become discolored as a result of infection. The beans in the infected pods approaching ripeness may escape infection because they are separated from the husk on ripening Management: Periodically remove the infected pods. Spray 1 per cent Bordeaux mixture with on set of rain and also frequent intervals. Provide frequent drainage and regulate shade to increases aeration. *Pseudomonas fluorescens* (biological control) liquid formulations @ 0.5% as soil and foliar spray (3 times per year- June, October & February) was found to be effective in reducing the Cocoa Pod rot and Stem canker. **Harvesting and Processing** Cocoa produces flowers from the 3rd year of planting onwards and economic yield starts from 5 th year. Properly well maintained tree yielded 1-2 kg of pods / tree/ year. It takes cacao pods 110 -- 130 days from pollination to ripening, depending on variety. In west Africa, there are two pod production season: the main season (July -- December) and light season (January -- April). The stage of maturity of the pod is best judged by change of color of pods. Pods that are green when immature turn yellow when mature and reddish pods turn yellow or orange. The change in color starts from the grooves on the pods and then spreads to the entire surface. The harvesting is to be done at regular intervals of 10 -15 days. To obtain high quality cocoa beans, avoid over ripening, damaged and diseased pods. Yield: 50-70 pods/tree/year. Tools required for harvesting include the following: sharp cutlass, for plucking those pods which are within easy reach on cacao trees; harvesting knives with short handle, for harvesting ripe pods well above the ground level; harvesting knife attached to longpole, for harvesting pods from the topmost part of cacao trees; and basket, for collecting harvested cacao pods. It is important that harvesting knives are very sharp so as to avoid damage to the bark of the trees. Bad harvesting technique reduce yield of cocoa in subsequent years. Therefore, while harvesting, the following points should be noted: 1. Cacao tree should not be climbed to avoid rubbing off those flower cushions which are the future pods 2. However low a pod may be on the tree, it must not be pulled off by hand because this may damage cushions and provide entrance for diseases and pests 3. During harvesting, the branches must not be shaken to prevent loss of flowers at upper branches 4. Greater care must be taken to prevent wounding the tree bark to prevent fungal infections 5. Diseased and damaged pods should be removed and buried far away from cacao plot 6. After harvesting, all good fermentable pods should be taken to the processing area 7. Breaking of pods for fermentation should start as soon as harvesting ends **Breaking the pods** The pods are broken by knocking them against blunt objects, e.g.a thick piece of wood or stone. The bean and pulp are removed from pods by hand. This method has been quick and efficient. A man can break 3000 pods per day. Pods should not be broken with a cutlass as this often results in damage to the beans which are then no longer suitable for fermentation. The extracted beans are collected in a basket or container. Care must be taken not to include beans of this categories: 1. Those which have started to germinate 2. Beans which are too small because they are immature 3. Beans looking dry or diseased in anyway 4. Beans from damaged pods 5. Beans from black or diseased pods. All the undesirable foreign elements including pulp and pieces of broken husk should be removed from the freshly extracted beans before fermentation. 1. Get the proper taste, colour and flavor associated with cocoa products 2. Kill the embryo and stop germination 3. Remove pulp or mucilage or sweatens so that the beans may dry properly 4. Loose the skin from the cotyledon thereby allowing easy and proper de-sheling during processing Types of fermentation include heap, basket, sweat box and tray fermentation. [Heap fermentation] - Banana or plantain leaves are used in heap method. Heap method is common. Its disadvantages are the problem of turning the beans, the long period of fermentation and its unsuitability for small quantity of beans. For breaking the pods, wooden billets may be used. After breaking the pods crosswise, the placenta should be removed together with husk and the beans are collected for fermentation. On an average 10-12 pods give 1 kg wet beans and 3 kg of wet beans (from 30-36 pods) give 1 kg of fermented and dried beans. Under normal cultivation practices, each cocoa tree yields about 1-2 kg annually [Basket method] **-** In this method, Bamboo or cane baskets of suitable size could be used for fermenting small quantity of beans. One or two layers of banana leaves are placed at the bottom with provision to drain the sweating. The basket is filled with the beans and the surface is covered with banana leaves. A small weight is placed over the banana leaves. The basket is placed over a raised surface to facilitate drainage of the sweating for one day. Later the basket is covered with thick gunny bags. The beans are mixed thoroughly on the 3rd and 5th days and again covered with gunny bags. The fermentation will be completed at the end of 6th day and the beans withdrawn for drying. Well fermented beans will be plumpy and filled with reddish brown exudates. The testa becomes loosened from the cotyledons. When cut open, the cotyledons will have a brownish colored with lots of ridges and furrow appearance in the centre with a brownish ring in the periphery. When above 50 per cent beans in a lot show the above signs, it can be considered as properly fermented. The problems of basket method of fermentation are similar to that of heap fermentation. [Box method] **-**The boxes of 60 cm X 60 cm X 45 cm made of wood and having reapers at the bottom to allow the sweating from the pulp to drain out and provide aeration are used. The boxes could be arranged in tiers for transferring beans from one to the next in line below. Two detachable wooden planks are provided on one side of the box for transferring (mixing) the beans by removing the planks. The beans are loaded on fermentation box and covered with banana leaves or gunny bags. The mixing of beans is effected while transferring to the next box after 24 hours. The temperature of the fermentation mass will rise to 45 -- 550C after about 48 hours of fermentation. Every alternate day the beans under fermentation have to be properly mixed for uniform fermentation. This has to be continued for 6 days. **Drying of cacao beans** Stored cacao is often seriously damaged by insect pest and mould. This type of damage is known to be greatly favoured by failure to dry cocoa properly. Production of good quality cacoa will therefore, not only depend on proper fermentation, but also on correct dry methods. Sun drying and artificial drying are methods of drying cacao beans. The fermented cocoa beans have considerable moisture (55 -69 %) and the drying rate is depend upon temperature and the airflow. Sun drying should be adopted as far as possible, as it gives superior quality produce compared to that by artificial drying. The moisture content of well dried beans is around 6 -- 7 %. Slow drying is preferable for better quality of the beans. Dried cacao beans are tested for dryness by two technique (1) squeezing the beans between fingers; a dried bean will produce a crack (2) cut through a sample bean, a dried bean will has it cotyledon separated. **Grading** To grade cocoa, representative samples are taken at random from the bulk. Several hundred such beans are taken but only 300 beans are finally selected and weighed. The 300 beans taken from the main crop should not weigh less than 300 g. There two grades of cacao based on the following criteria: 1. Grade 1 cacao: less than 3% slaty beans; less than 3% mouldy beans; less than 3% other defectives 2. Grade II cocoa:less than 5% slaty beans, less than 4% mouldy beans, less than 5% other defectives Example of defective beans are smoky beans, velvety beans, black beans, mouldy beans, weevilled beans, flat beans, empty beans, germinated beans, slaty beans and purple beans **Storage** The flat, slate, shrivelled, broken and other extraneous materials are removed. The cleaned beans are packed in fresh polythene lined (150 -- 200 gauge) gunny bags. The bags are kept on raised platform of wooden planks. The beans should not be stored in room where spices, pesticides and fertilizers are stored as they may absorb the odour from these materials. **Bean quality** Cocoa quality depends on various factors, but primarily on the cocoa variety and the post-harvest handling. Generally, fine or flavour cocoa beans are produced from Criollo or Trinitario varieties, while bulk cocoa beans come from Forastero trees.