• Thoebroma cacao Family Sterculiaceae
• Economic Importance to Ghana
• Known in Ghana as the golden pod
• Production Between 1957 and 1966,
• 300,000 metric tons per annum valued at about
• Making Ghana the leading producer of cocoa in the
Economic importance of cocoa
• Revenue from cocoa was used to provide
• Free education,
• Free medicare
• Subsidy for housing and transport
• Road network Ghana from 1957 to 1966
• Population of 6 million people
How cocoa came and became
successful in Ghana.
• Origin : Amazon forests on the slopes of Andies
in South America (Brazil) and Central America.
• It grows as a small under storey tree, under tall
big trees in the Amazon forest.
• Natives call it food for the gods (Theobroma)
• Spanish (colonialists) (conquistadors) found that
the S/A natives prepared a festive food from dried
roasted and fried cocoa beans, maize and pepper.
• This native food was bitter to the Spaniards. The
Spaniards substituted milk and sugar for maize and
pepper and produced chocolate.
• There was a crave for the product in Europe and
chocolate business was developed.
• Raw materials needed to support the chocolate
• Spaniards and other Europeans attempted to grow
the crop in Europe, but the winter weather did not
permit the cultivation of cocoa in the cold European
• So the crop was taken to their tropical colonies.
• From S/A the Spaniards took cocoa to Fernando Po
now Cape Verde Islands.
• From Cape Verde, Tetteh Quarshie brought cocoa to
Ghana in 1879
Types of Cocoa
Cocoa color of
no of seeds
Type unripe pods ripe pods per pod
Criollo green or
(Criollos produce fine cocoa but non commercial because of disease
Trinitario Hybrid between criollos and forasteros. Combine the
two characters of criollos and forasteros
Subtypes of Forastero cocoa
1. Upper Amazon Forastero
• Self Incompatible, vigorous, some with resistant or
tolerance to black pod, and swollen shoot virus
• Eg. Nanays (Na), Parinaris(P) Scavinas (Sca), Iquitos
2. Lower Amazon Forastero
Self compatible, uniform bean size and slow growing,
intolerant to full exposure, sensitve to swollen shoot
eg Amelonado (Tete Quarshie cocoa)
The success of Amelonado in Ghana
1. Absence of Witches broom (Crinipellis perniciosa)
and seed rot (Monilia roreri ) diseases in W/A
2. Lower incidence of blackpod disease in W/A
compared to S/A
3. Amelonado is self fertile- No barrier to fruit set after
pollination. Farmers could plant unselected seeds
obtained from from nearby farmers.
• The slash and burn shifting cultivation practiced by
W/A farmers left tall forest trees to provide the
permanent shade required for the crop.
• Temporary food inter-crops of plantain and cocoyam
provided the temporal shade for the young seedlings.
• Abundant soil organic in the virgin forest in those
years supported the growth of Amelonado, which
reached full bearing after 8-10 years.
• Fermentation and Drying
• The small heap fermentation system practiced by the
W/A farmer was ideal to produce good well fermented
• The dry weather from mid-November to January
provided ideal weather for fermentation and drying of
• The uniform bean size of 1gm, the unique flavor after
fermentation favored processing into chocolate
6. Socio-economic factors
• Well organized market for purchasing dried cocoa
• Social Factors ( money for Christmas and end of year
• Prestige of a cocoa farmer ( farms as security for
• Farmers’ adequately motivated.
Basic Ecophysiology of Cocoa.
• The seed has no dormancy.
• Seeds become fully mature before pods become ripe.
• Therefore seeds from semi ripe pods can be used for
planting, but for fermentation and processing, seeds
must be harvested from ripe pods.
• Seeds may germinate in unharvested overripe pods.
• Seeds lose their viability very quickly on exposure.
For cultivation, fresh seeds from ripe pods are
used. Seeds germinate in overripe pods.
• Seeds are killed after 8 minutes at 40C ( intolerant
• Can be stored in Charcoal powder or sawdust at
30% moisture after sweatings are removed for 1013 weeks
• Removal of seed coat enhances germination
• Young seedlings require some shade for growth.
• Seedlings vary greatly in their shade requirements.
Lower Amazon forasteros are intolerant to full
exposure. Upper Amazon types like “scavinas”
tolerant to full exposure
• The seedling growth is orthotropic: with 3/8 phyllotaxy.
After 1-3 years the terminal bud of the seedling divide
to form 3-5 lateral branches called fans with ½
phyllotaxy. The process is called jorqueting.
• The point of branching is called jorquette.
• Just below the jorquette, a lateral bud shoots
up to continue the upward growth of the
seedling. Growth is thus in tiers (steps).
• Flowering starts soon after the first jorquette.
• The main stem is called chupon. Height of
cocoa is regulated by pruning chupons or
Growth of the adult tree
• Adult tree grows in flushes.
• Terminal buds on young branches produce
shoots simultaneously in response to rainfall
and soil moisture conditions especially after
period of drought.
• Mature tree is deciduous shedding old
leaves during the dry season. Massive leaf
litter could be found under cocoa plantations.
• Flowers are formed on the main trunk and on the
branches. This phenomenon is cauliflorous. The
flowers are perfect and pentamerous.
• ie. Calyx
• Ovary with 5 Sepals: Sepals fuse to form the pod.
• Unique, hormorphic, mulliallitic, sproplytically
• S1>S2=S3>S4>S5>S6 after pollination.
• Pollen tube grows but pollen nuclei unable to
Significance of incompatibility on cocoa production
50% ovule abortion
no fruit set
50% ovule abortion,
no fruit set
Basic ecophysiology ctd
• Cushions: Compressed branches on stem from where
• Pollination: Midges and Pysillides
• Cherelles: Young fruits below six weeks after
• Cherelle wilt: Dropping of young cherelles.
Physiological trimming mechanism to prevent overbearing.
• Pods: Mature after 5 months attached to the cushion
by the fruit stalk.
Stake, 2-4 seeds/hole,
nursery in June
• Permanent shade
Removal of basal fans,
when 2nd chupon is formed
Stop growth at 2nd jorquette
to shape trees
P205, Mg and K.
2 weeks regular
disease and quality
Effects of shade and fertilizer on cocoa
YIELD IN IB DRY COCOA PER ACRE
No Shade+No Fertilizer
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
YEARS AFTER 10 YEARS OF GROWTH
Fermentation and quality of cocoa
• During fermentation
• Mucilaginous sugary sweatings acted on by yeast and
converted to alcohol
• The process leads to rise in temperature
• Aerobic phase: alcohol converted to acetic acid and
carbon dioxide by acetone bacterial
• Bean color changes to purple brown due to enzyme
action on the anthocinines
• Chocolate flavor and aroma develope
Types of Fermentation Systems
1. The small heaps on banana leaves practice by
2. Tray fermentation developed at CRIG
- tray size 1mx1.5mx10cm
- Base of trays slated with palm fronds or net and
then staked together and covered with sacks.
3. Box fermentation
- Box sizes about 2m x1.5m x1m with drainage holes
-boxes arranged in 3 tiers. Beans loaded into the middle
box from the top after two days and then to the bottom
box after the next two days. Fermentation is
completed after the next 2 days
• Determined by undesirable types including
• Slaty beans as a result of improper
• Mouldy beans due to black pod disease
• Flat beans due to incompatibility factors
• Germinated beans due to over- ripeness
• Placenta due to negligence
• Acid cocoa due to genotype and large heap
Challenges posed by the Swollen Shoot disease
• CSSV - viral disease
Transmitted by mealybugs
- Virus endemic in forest trees
e.g. Cola chlamydanta , Bombax spp
by 1948, 38,000,000 trees removed.
The only control measure is to cut out diseased and
• Cocoa Research Institute of Ghana was
established to find solutions.
• Possnette visit to Trinidad.
(1) 100 upper Amazon pods ( prefix T)
4,000 plants grown from the 100 pods
• Six selections
(2) Cross with Amelenado – Tafo Hybrids