Cocoa-Based Agroforestry Production Systems

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Cocoa-Based Agroforestry Production
Systems
http://nationalzoo.si.edu/conservationandscience/migratorybirds/research/cacao/somarrib
a.cfm
Eduardo Somarriba
and John Beer
Historical Account: Cocoa in Talamanca and Bocas Del Toro
Cocoa was probably used by local amerindians before Spaniards attempted to settle in the
Colonial Talamanca region (which then included Bocas del Toro).
Cocoa was produced, and traded, during colonial times in Spanish settlements in the
Talamanca Region. However, agricultural settlement never lasted in the area due to intertribal wars, disputes among colonial authorities, and rebellions against Spanish ruling.
Major agricultural development started in 1860’s with the commercial production of
bananas.
Cocoa commercial plantations were established to replace banana plantations decimated
by banana’s Panama disease (Fusarium oxysporum). Cocoa plantations peaked in 1920’s.
Banana production ended in 1934 and moved to the Pacific Region of Costa Rica and
Panama. Cocoa was the most important commercial crop between 1940-1970. Banana
production was re-inititated in 1978 with new varieties resistant to Panama disease.
Cocoa plantations were converted to banana in the lowlands; most cocoa is now produced
in hilly areas.
Cocoa prices peaked in 1977-1978, but monilia (Moniliophthora roreri) appeared in 1979
and production dropped to nearly zero. Cocoa prices went down in 1980 and remained
low until 1993. Prices have increased between 1994-1998, from less than 1 US$/kg to
around 1.6 US$/kg. Management levels of cocoa plantations depend on price levels.
Cocoa production was promoted between 1982-1987 in both Costa Rica (Talamanca) and
Panama (Bocas del Toro) using allegedly more productive genotypes. The CATIE-GTZINRENARE agroforestry project started operations in 1986; shade management in cocoa
plantations was identified as a major research line.
Cocoa-Based Agroforestry Systems Researched In Talamanca
and Bocas Del Toro
Research design in 1986/1987 attempted to address several farm scenarios with cocoa as
the main crop: 1) farmers in fertile, lowlands interested in establishing new, well
managed cocoa plantations (cocoa production only, Talamanca); 2) some farmers were
interested in establishing new, well managed plantations combining cocoa and timber
production (Bocas del Toro); 3) shade regulation in existing farms as a means to increase
cocoa production required replacing un-productive, un-regulated shade by a new,
productive, easy to manage shade canopy; some farmers were willing to concentrate only
on cocoa, others were interested in both cocoa and timber production; and 4) plantain was
introduced in 1981 and became the major economic alternative for farms located in
lowlands, close to the local markets; diversified systems combining cocoa and plantain
can be attractive to them.
Five cacao-based agroforestry systems were selected for research: 1) leguminous tree
species (Gliricidia sepium, Erythrina poeppigiana or Inga edulis) used as mono-specific
shade in new cocoa plantations; 2) timber tree species (Cordia alliodora, Terminalia
ivorensis or Tabebuia rosea) used as mono-specific shade in new cocoa plantations; 3)
leguminous trees for shade conversion in existing cocoa plantations; 4) timber species
(same as above) for shade conversion in existing cocoa plantations; and 5) cocoaplantain-timber systems for intensive production.
Experiments of each type were established in private farms in collaboration with farmers.
Research included: three farms of type 1 experiments, two farms of type 2, two farms of
type 3, five farms of type 4, and two farms of type 5. In each farm, treatments (shade
species) were replicated 3-4 times; each experiment covered 1-2 ha. Research was
initiated in 1989-1990 and all experiments were monitored between 1989-1995. From
1995 to present only one experiment of types 1,2, and 5 are monitored; four farms with
type 4 experiments are presently monitored. Preliminary results have been published (see
reference list). In what follows we summarize results from research conducted in
Turrialba, Talamanca and Bocas del Toro.
What We Know
 Differential management (pruning or thinning) of radically different shade species
(service or timber producing) can result in similar cocoa production.
 In soils with medium to high natural fertility levels and with moderate chemical
inputs, differential management favors the use of timber species over the
traditional service, leguminous species when standard financial analyses are used.
 Crop losses due to fungal pathogens were not affected by the selection and
management of the shade species nor of the cocoa genotypes (a total of 12
interclonal crosses from the cocoa colection of CATIE, Turrialba, Costa Rica).
Loss due to pathogens are determined only by cultural practices in nearby farms,
which determines the availability of sources of innoculum. Losses levels varied
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between 35-75% depending on the local context of the experiment. In a given
location, losses were similar between shade species and between cocoa genotypes.
Major differences in cocoa production are determined by the selection of the
genotype. Adjusting losses to a zero level (which gives an idea of the productive
potential of the genotype), cocoa production per genotype varied between 700 –
2400 kg/ha/yr of dry cocoa beans under identical conditions.
Even larger variability in cocoa yields are observed at the plant level, opening the
possibility for the selection and vegetative reproduction of highly productive
genotypes. A large majority of the cocoa plants produce less than 1 kg/plant/yr,
thus limiting yields.
Pathogens are still an unresolved problem in cocoa production in Talamanca and
Bocas del Toro, specially, monilia. Witches-broom (Crinipelis perniciosa) is a
persistant threat. Pathogens cause less harvestable production and more costs.
Weed management is critical in newly established cocoa plantations. The
selection and management of the shade species can drastically reduce this
problem.
Introducing either leguminous or timber species in existing cocoa plantations is a
simple and cheap alternative to replace undesirable existing shade canopies.
Timber growth is excellent in both new and existing cocoa plantations in the
study region. Timber trees benefit from the medium to high natural soil fertility
levels of sites where cocoa in grown and year round water availability in the
Talamanca and Bocas del Toro region, Management of the cocoa (weed control,
fertilization, crown pruning, etc.) ameliorates from interspecific competition at
early eages, and low shade tree densities (70-280 trees/ha) delays intraspecific
competition.
The short rotation to produce commercial timber trees facilitates the incorporation
of small-medium farms in reforestation programmes. Financial performance of
most systems tested is satisfactory, specially when labor is cheap. Plantain, timber
trees and the use of short term crops as temporary shade (in new cocoa
plantations) improves the financial performance of cocoa plantations.
Soil organic material increases under shaded cocoa, even on soils with high initial
organic material content. Pruned leguminous shade trees have a greater effect than
unpruned timber trees.
Cocoa production is primarily determined by light levels when the same genetic
material is compared. The response to improved soil fertility is only realized
when shade levels are managed at relatively low levels (e.g. by tree pruning).
Fine root growth of cocoa occurs at the beguining of the rainy season while for
many tropical trees, including C. alliodora and E. poeppigiana, it occurs at the
end of the rainy season.
The use of leguminous shade trees, especially when they are regularily pruned,
accelerates nutrient cycling.
Litter production and net primary productivity of shaded cocoa plantations is
similar to that of natural tropical forest and is much greater than most tropical
agricultural systems.
C sequestering in shaded cocoa systems was 5 Mg/ha/yr over 10 years when sugar
cane fields were converted to cocoa plantations.
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These systems can be sustainable with little and even no external inputs
(indicators: net primary productivity, soil organic material, commercial
production).
What We Think We Know
 Enough information is available on cocoa agronomy (shade requirements) and
silviculture to design sound simple cocoa-based agroforestry production systems.
 Diversified systems perform financially better than cocoa monocrops. Companion
early crops must respond to local markets, access roads, etc.
 Timber species can be combined with leguminous species to ensure quick soil
cover and reduce weed infestation, reduce management costs and increase
financial performance.
 There is plenty of room for improving cocoa production by introducing pathogen
resistant, high yielding genotypes. Clonal materials seem more promising than
sexual plants.
 Cocoa plantations are suitable for small farmers in remote areas and buffer zones.
Dried cocoa beans can be stored without rotting, value per unit weight is high thus
facilitating transport to remote markets, forest-like structure enhances biodiversity
and smooths the gradient between protected areas and surrounding agricultural
areas.
 Tested genotypes are suitable for low shade levels (high yields). The yield level –
shade level – fertility level interaction may predict that this is correct when
natural soil fertility is high (like in our study sites), when fertilizers are added, or
when both hold true.
 Increased organic material inputs improve nutrient availability for trees and
cocoa.
 The presence of the shade trees reduces nutrient leaching from the system.
 The presence of mixed shade species accelerates litter decomposition and hence
nutrient cycling.
 How to manage a diverse shade canopy without reducing potential cocoa yields.
What We Do Not Know
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Performance of high yielding clones under small farm scenarios, with low
chemical inputs and higher shade levels.
Comparative advantages of using N-fixing and/or mulch producing leguminous
trees as shade over cocoa under low fertility soils when chemical fertilizers are
not available.
More diverse shade canopies can be designed by adding fruit species that satisfy
the following criteria: a) good shade characteristics, b) valuable for markets,
home consumption or biodiversity maintenance, c) produce nuts or non perishable
fruits that can be stored and profitably transported to distant markets.
Damage levels to cocoa plants (and effects on cocoa yields) during tree felling
and timber extraction.
Farmers rationale for shade canopy design and management.
Shape of the interaction: yield-shade-fertility-costs.
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How to manage shade trees within an integrated pest management programme in
order to reduce pest/disease incidence and/or pesticide applications.
The effect of increased soil organic material on biodiversity (e.g. soil flora and
fauna).
Whether it is preferable to have fast or slow decomposing litter (e.g. is fast
cycling of nutrients more important than protection of the soil surface?).
Economic (including externalities) contrasts of cocoa production under mixed
shade versus mono-specific shade strata.
Management regimes for fruit trees to enhance yields (home or commercial use)
that also improve cocoa yields (e.g. pruning regimes which have both objectives).
How important are cocoa plantations in buffer zones as a means of extending
protected areas and whether biodiversity conserved increases as a result.
Effects of shade levels on cocoa (bean) quality.
Effect of fast timber tree growth rates, when cultivated in cocoa plantations, on
timber quality.
Sustainability in Cocoa Production
1. Minimizing environmental degradation
Shaded cocoa plantations provide good soil cover after the establishment
phase (soil erosion may not be a prevalent ecological problem in most
plantations), pesticides and fungicides are of limited use in normal
operations (toxic pollutants are not a critical issue in cocoa producing
areas), herbicides are regularily used, inorganic fertilizers are seldom used
in remote areas; intensive cocoa cultivation requires 0.5-1.5 Mg/ha/yr.
Typical fertilizer amounts used in the experiments in Talamanca and
Bocas del Toro: 500 kg/ha/yr of commercial formulations. Environmental
degradation can be minimized by: 1) managing ground cover (selection of
shade species, companion crops, plantation densities, planting
arrangements) to reduce weed infestation and the use of herbicides; 2)
avoid intensive cultivation systems to reduce inorganic fertilizers; and 3)
choosing shade species that produce large quantities of organic material
(or by pruning regularly, force the trees to do this).
2. Maximizing biological diversity
Moderate cocoa yields (1 Mg/ha/yr) should be aimed at. Shade levels in
adult plantations must average 30%, with seasonal variations between 2050%. Tree canopies may include 100-150 trees/ha in adult plantations.
Tree species must be selected according to shading characteristics,
productive outputs, and environmental services required (e.g. perching
sites for birds, food for mammals, honey production, etc.). Diversification
of commercial components (species) should reduce the need to increase
cocoa yields by using more intensive management (e.g. agrochemicals).
Temporary crops add to biological diversity of the systems. A narrow
genetic base for cocoa is expected since only high-yielding clones (a
mixture of 7-10 clones) are recommended.
3. Long-term yields
Matching shade canopies (shade levels, botanical composition, pruning
and thinning regimes) to site characteristics (fertility levels,
socioeconomic conditions of the farmer) and appropriate cocoa genotypes
can result in acceptable, long-term yields (cocoa, timber, fruits,
environmental services, etc.).
4. Improved livelihoods of small-scale farmers
From the production side, adequately designed cocoa-based agroforestry
systems (above) con result in productive, ecologically sound production
systems. Prices, higher and less variable, need to be improved to motivate
farmers.
Recommendations
Implement new, on-farm research on the ecological, financial, agroforestry aspects of
cacao-based agroforestry prototypes in remote and buffer zone areas. A first draft of the
prototype is ready for further discussion and improvement. Project development and
funding should be addressed.
Design and implement, researcher-controlled, on-farm experiments focusing on the study
of the shade-fertility-yield interaction in cacao – based agroforestry systems.
Relevant Literature
ALPIZAR, L; H.W. FASSBENDER; J. HEUVELDOP; H. FOLSTER ; G. ENRIQUEZ,
1986. Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia
alliodora) and poró (Erythrina poeppigiana) in Costa Rica. I. Inventory of organic matter
and nutrients. Agroforestry Systems 4:175-189.
BEER, J. 1987. Advantages, disadvantages and desirable characteristics of shade trees for
coffee cacao and tea. Agroforestry Systems 5:3-13.
BEER, J. 1988. Litter production and nutrient cycling in coffee (Coffea arabica) or cacao
(Theobroma cacao) plantations with shade trees. Agroforestry Systems 7:103-114.
BEER, J. 19991. Implementing on-farm agroforestry research: lessons learned in
Talamanca, Costa Rica. Agroforestry Systems 15:229-243.
BEER, J; A. BONNEMANN; W. CHAVES; H.W. FASSBENDER; A.C. IMBACH; I.
MARTEL, 1990. Modelling agroforestry systems of cacao (Theobroma cacao) with
laurel (Cordia alliodora) or poro (Erythrina poeppigiana) in Costa Rica. V Productivity
indices, organic material models and sustainability over ten years. Agroforestry Systems
12:229-249.
BEER, J; MUSCHLER, R; SOMARRIBA, E; KASS, D (1997) Shade management in
coffee and cocoa plantations. Agroforestry Systems 38:139-164.
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