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Introduction Cocoa is an economic tree crop with various
industrial uses. Cocoa beans are used in the manufacture of cocoa butter, Bournvita, Milo, Chocolate, ice cream, soft drinks, pharmaceutical and food preparations. Cocoa is also a very important cash crop through which much foreign exchange is earned. The current production of the crop in Nigeria is estimated at 150,000 metric tonnes on an area of about 550,000 hectares and only about 20% are of improved varieties. The remaining ones are old and unimproved varieties which need to be replanted. This guide is produced with a view to acquaint the farmer with the current information on production practices.
-Climatic Requirement: Cocoa is a low-altitude crop. Cultivation is
most suitable in the rain forest zone with an annual rainfall from 1200 to 2,500mm, temperature of23-34oc and sunshine hours of about 1,000 - 2,000 per annum.
Soil Requirement: Cocoa requires fertile, deep and well drained
soils with appreciable amount of clay (30-45%) in the sub-soil layer. The high amount of clay in the sub-soil layer enables the soil to hold the crop firmly and retain soil moisture during the dzy season. The top soil should be gravel-free without iron concretions, and also rich in organic matter.
Site Selection Select a site with an average rainfall of
150mm per month for at least nine months of the year, i.e. a minimwn of 1 ,350mm per annum. The
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site also should have an optimal average temperature of around 25 .5°C throughout the year, with dai ly range of not more than l0°C. Site of strong dry winds should also be avoided to prevent tree falls as well as dehydration of floral organs.
Varieties: Improved varieties of cocoa seedlings can be
obtained from the State Ministry of Agriculture Nurseries, Agricultural Development Projects (ADPs), Cocoa Development Units (CDUs) and Cocoa Research Institute ofNigeria (CRIN) substation in your area.
Land Preparation: This involves the underbrushing of the un
dergrowth, stumping of all trees and packing of all the debris away from the site. For Cocoa, land preparation can be done in four ways:
1. Total clearing without burning (this is the most recommended practices)
u. Total clearing with burning. This is not recommended because the organic layer and some ofthe nutrients may be adversely affected, for example, the soil nitrogen will volatilize.
m. Selective thinning - After underbrushing, few trees are removed and the remaining are left to serve as natural shade to cocoa.
IV. Avenue clearing- The bush is allowed to remain and traces of about one metre wide are cut at intervals of 3 metres apart.
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Lining out/Pegging Select a baseline which must be the longest
axis of the area .. Line out the field at 3m apart. Peg at 3m on the line for cocoa and also at 3m apart for the shade tree.
Fig. 1 ; Pegging Dimensions
Holing Holes of about 30cm x 30m x 30cm dimen
sions are dug for cocoa and the shade plants, which are usually plantains. Holes for plantains are dug in April to allow planting, while those for cocoa are dug in May/June.
Transplanting of Seedling Cocoa seedlings are transplanted to the field
in May/June when the rains have become steady. Early planting, as recommended above, enables the seedlings to receive enough moisture from rain water to get established before the dry season sets in. Late transplanting beyond July 15th should be avoided. The seedlings are placed in the dug holes with the ball of earth still left intact after the polythene bags have been carefully removed. This is to ensure that the roots of the seedlings are not damaged during transplanting.
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Fig. 2: Cocoa seedlings for planting.
Supply of Missing Stands: Supply of missing stands technically referred to
as "Gapping-up" in tree crop production is done within the first to second year of establishment of coca in order to avoid the newly transplanted seedlings being dwrufed or eclipsed by the older seedlings.
Fertilizer Application If the right type of soil is used, this may not be
necessary in cocoa until about 15 - 20 years after planting. Apply Urea at 374kglha single super phosphate (SSP) at 375kglha and 97kg potassium chloride per hectare for mature cocoa. Where the soil is poor, application of 150- 300kg SSPor 126kg Triple Super Phosphate (TSP) per hectare can be carried out to satisfy the nutritional requirements of cocoa seedlings within the age of 4- 6 years.
Management of Cocoa: Mulching
Mulching is carried out during the dry season (i.e. November- March) to reduce soil moisture loss through evaporation. Dry organic materials such as grasses, plantain and banana leaves are used. Use of woody materials shoud be avoided to keep off the attack of termites.
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Fig. 3: Mulching of a Cocoa Plant.
The mulching is laid in circles round the tree crops but with a distance of about 7.5 - 15.0cm away from the tree crops to prevent termite attack. The thickness of the mulch can also be between 7.5 and l5.0cm. Shade Management
1bis operation is carried out only in cocoa plantations. Effective shade management is done in cocoa plantations by regularly desuckering plantain trees to about 2 suckers per mother plantain. Plantain is used as shade tree in cocoa because it does not compete much with cocoa for nutrients and water, unlike banana Improper management of shade results in high incidence of pests and diseases e.g. blackpod diseasee (Phytophthora palmivora ) in cocoa
Pruning Pruning is done in cocoa to attain a desired
shade and improve the flower formation. Pruning also improves the ventilation of cocoa farms, resulting in the reduction of pest and disease inci-
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dence. Dead and unwanted branches are also re· moved through pruning, leading to conservatior' of nutrients. Pruning is carried out through the use of sharp tools like cutlases pruning knives, seca· teurs, pruning shears, pruning saw and chain saw~ so as to have clean and smooth cut surfaces.
1. Weed Control Weed incidence poses a serious problem in
cocoa especially at the juvenile stage when leaf canopies are yet to close. The common weeds include Chromolaena odorata (Siam weed), Panicum maximum (Guinea grass), Euphorbia hirta (milk weed), Fleurya aestuans (tropical nettle weed). Weeds can be controlled manually by slashing, chemically through the use of contact and systemic herbicides and through the practice of intercropping.
The recommended herbicides are : Gramoxone (paraquat) at 3L/ha: Gramuron (Paraquat+ diuron), 5Uha). Round-up (glyphosate 4L/ha). A parasitic weed, mistletoe is at present best controlled through physical removal with sharp tools. Removal should be done before seeding and the weeds removed should be burnt.
n. Insect Pests and Diseases The whole plant which consists of the flow
ers and seeds/fruits, the foliage, stem and roots can be attacked by a myriad of pests and pathogens at various stages of growth and at maturity.
a) Insect Pests The major insect pests are the termites
(Nasurtitermis spp and Macrotermites natalensis ), mirids also referred to as capsids (Sahlbergella singularis and Distantiella theobromae ), the mealy
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bugs (Planococoides njalensis and P. citri),and the grasshopper.
Recommended insecticides for use against cocoa pests in Nigeria include:
Gamma! in 20EC at 3.16 litres!ha Kokotine 20EC at 3.16litres/ha Capsitox 20EC at 2.16 litres.ha Unden 20EC 2.8 at 2.16 litres!ha Elocron 5CWP at 0.82 kgfha Lindane 20 EC of3.16 litre/ha
b) Diseases The major diseases of cocoa in Nigeria include:
(i) Pod rot caused by Phytophthora palmivora, Fusarium so/ani, Botryodiplodia theobromae etc.
(ii) Swollen shoot disease caused by the Cocoa Swollen shoot virus (CSSV)
Recommended fungicides for use against Black Pod Disease in Nigeria
* Perenox at 40g/9litres of water * Kokobre Sandoz at 43.3g/a litres of water * Brestan 60 at 13.3g/9litres ofwater * Kocide 10 at 40.5g/9litres of water * Copper Sulphate plus lime (Bordeaux mixture)
90.00gCu2S04 + 36glimein9Iitresofwater.
Control of CSSV is through * the removal of infected trees * elimination of mealybug vectors * use of tolerant clones
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Har-vesting In Nigeria, there are two pod production sea
sons: the main season, July to December and the light crop season- January to April,. Harvesting should be done twice a year: once for the main crop season and at least one for the light crop season. To ensure the production of quality beans, it is essential that only mature ripe pods are harvested and processed promptly.
Tools required for pod harvesting are sharp cutlass for plucking those pods which are within easy reach on the cocoa trees. Harvesting knife with short and long handles are required for harvesting ripe pods well above ground level, and pods from the top most part of the tree respectively. In pod harvesting the following precautions should be taken very seriously.
1. harvest with very sharp knives so as to avoid damage to the bark of the trees;
2. do not climb cocoa tree to harvest in order to avoid rubbing off flower cushions which are source of future pods;
3. ripe pods must not be pulled off by hand because this may result in damage to the cushions or provide a hiding place for insect pests;
4. after harvesting, all good fermentable pods should be taken to the processing area without delay
5. it is very essential to break the pods for fennentation soon after harvesting in or-
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der to prevent the onset of beans germinating with in pods or fennentation which wi ll be incomplete.
Fermentation: Fem1entation is one of the most important
operations in the preparation of cocoa beans for the market. As a rule, maximum return is obtained only from properly fem1ented and clean cocoa. It is therefore necessary to ferment cocoa beans in order to: l. get the proper taste, colour and flavour as
sociated with cocoa products;
2. kill the embryo and stop germination;
3. remove pulp or mucilage so that the beans may dry properly; and
4. loosen the skin from the cotyledon thereby allowing easy and proper de-shelling dur-. . mg processmg.
For further information on fermentation procedure and types, contact the CRIN station nearest to you.
Drying of Cocoa: Production of good quality cocoa depends,
not only on proper fermentation, but also on correct drying methods. Two drying methods commonly used are sun drying and artificial drying.
Sun drying is simple, cheap and very effective for most farmers who usually have small cocoa holding. Drying is done on concrete slabs o r raised plat forms. The area selected should be well
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cemented with adequate drainage round it. Measures should be taken to keep off the encroachment of domestic animals.
After being fully fermented, the beans are spread as thinly as possible to avoid damage to the beans for sun drying. During the process of drying, all foreign matters and malformed beans are removed. Uniform drying is ensured by separating the beans to prevent sticking together.
As an alternative to concrete slabs, raised platforms can be constructed to dry cocoa beans. Materials required can be obtained around the farm. The height could be 50cm to 1 OOcm. Slatted mats are spread on the platform for drying the beans. In good sunny weather, it takes less than two weeks to dry the beans properly.
In the absence oflong sunny periods, artificial drying may have to be used. Consult the C RIN
office near you for more details.
Storage of Cocoa Cocoa beans should be properly dried (i.e.
having a moisture content of7 percent) before storage. Well-dried beans will crack when squeezed between the fingers. Another approach which is more accurate is to cut through the sampled beans with a knife and, if properly dry, the cotyledon will separate easily. In storing cocoa beans the following care must be taken to ensure quality produce: 1. Store the dry beans in clean basket or new
sacks and make sure that the containers are kept off the ground and in weather- proof surroundings. Old sacks which have been used for storing grains or other foodstuffs should not be used as they are likely to har-
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bour insects which may attack the beans. 2. Cocoa should not be stored near maize, to
bacco, or other foodstuffs and should be kept from smoke as this will produce smokysmelting beans.
Marketing: Stored produce should be sold to the buyers
or export finns as soon as possible. Prices are fixed for the year and there is no advantage in keeping cocoa in the house where it is liable to deteriorate in quality.
SUMMARY POINTS.
* Prepare land in good time
* Plant improved variety from proven sources
* Transplant at correct time.
* Mulch young trees
* Harvest regularly
* Maintain a weed free farm
* Prune plants regularly
* Control pests and diseases
* Ferment and dry Cocoa beans properly
* Store clean dry beans appropriately
* Market the beans early.
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