Cocoa-Based Agroforestry Production Systems

Eduardo Somarriba and John Beer

Historical Account: Cocoa in Talamanca and Bocas Del Toro

  1. Cocoa was probably used by local amerindians before Spaniards attempted to settle in the Colonial Talamanca region (which then included Bocas del Toro).
  2. 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 inter-tribal wars, disputes among colonial authorities, and rebellions against Spanish ruling.
  3. Major agricultural development started in 1860's with the commercial production of bananas.
  4. Cocoa commercial plantations were established to replace banana plantations decimated by banana's Panama disease (Fusarium oxysporum). Cocoa plantations peaked in 1920's.
  5. 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.
  6. 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.
  7. Cocoa production was promoted between 1982-1987 in both Costa Rica (Talamanca) and Panama (Bocas del Toro) using allegedly more productive genotypes. The CATIE-GTZ-INRENARE 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) cocoa-plantain-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

  1. Differential management (pruning or thinning) of radically different shade species (service or timber producing) can result in similar cocoa production.
  2. 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.
  3. 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 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.
  4. 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.
  5. 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.
  6. 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.
  7. Weed management is critical in newly established cocoa plantations. The selection and management of the shade species can drastically reduce this problem.
  8. Introducing either leguminous or timber species in existing cocoa plantations is a simple and cheap alternative to replace undesirable existing shade canopies.
  9. 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.
  10. 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.
  11. 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.
  12. 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).
  13. 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.
  14. The use of leguminous shade trees, especially when they are regularily pruned, accelerates nutrient cycling.
  15. 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.
  16. C sequestering in shaded cocoa systems was 5 Mg/ha/yr over 10 years when sugar cane fields were converted to cocoa plantations.
  17. 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

  1. Enough information is available on cocoa agronomy (shade requirements) and silviculture to design sound simple cocoa-based agroforestry production systems.
  2. Diversified systems perform financially better than cocoa monocrops. Companion early crops must respond to local markets, access roads, etc.
  3. Timber species can be combined with leguminous species to ensure quick soil cover and reduce weed infestation, reduce management costs and increase financial performance.
  4. There is plenty of room for improving cocoa production by introducing pathogen resistant, high yielding genotypes. Clonal materials seem more promising than sexual plants.
  5. 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.
  6. 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.
  7. Increased organic material inputs improve nutrient availability for trees and cocoa.
  8. The presence of the shade trees reduces nutrient leaching from the system.
  9. The presence of mixed shade species accelerates litter decomposition and hence nutrient cycling.
  10. How to manage a diverse shade canopy without reducing potential cocoa yields.

What We Do Not Know

  1. Performance of high yielding clones under small farm scenarios, with low chemical inputs and higher shade levels.
  2. 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.
  3. 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.
  4. Damage levels to cocoa plants (and effects on cocoa yields) during tree felling and timber extraction.
  5. Farmers rationale for shade canopy design and management.
  6. Shape of the interaction: yield-shade-fertility-costs.
  7. How to manage shade trees within an integrated pest management programme in order to reduce pest/disease incidence and/or pesticide applications.
  8. The effect of increased soil organic material on biodiversity (e.g. soil flora and fauna).
  9. 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?).
  10. Economic (including externalities) contrasts of cocoa production under mixed shade versus mono-specific shade strata.
  11. 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).
  12. How important are cocoa plantations in buffer zones as a means of extending protected areas and whether biodiversity conserved increases as a result.
  13. Effects of shade levels on cocoa (bean) quality.
  14. 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 20-50%. 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

  1. 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.
  2. 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.

CALVO, G; SOMARRIBA, E. (1998) Sombras leguminosas para cacaotales: costos y beneficios financieros. CATIE, Serie Técnica, Informe Técnico. (En preparacion).

CALVO, G; PLATEN, H von. 1996. Cacao - laurel - plátano: costos y beneficios financieros. CATIE, Serie Técnica, Informe Técnico #264. CATIE, Turrialba, Costa Rica. 53 p.

FASSBENDER, HW; J. BEER; J. HEUVELDOP; A. IMBACH; G. ENRIQUEZ; A. BONNEMANN, 1991. Ten year balances of organic matter and nutrients in agroforestry systems at CATIE, Costa Rica. Forest Ecology and Management, 45:173-183.

FASSBENDER, HW; L. ALPIZAR; J. HEUVELDOP; H. F?-LSTER; G. ENRIQUEZ, 1988. Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) and poro (Erythrina poeppigiana) in Costa Rica. III: Cycles of organic matter and nutrients. Agroforestry Systems 6: 49-62.

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HEUVELDOP, J; H.W. FASSBENDER; L. ALPIZAR; G. ENRIQUEZ; H. F?-LSTER. 1988. Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) and poro (Erythrina poeppigiana) in Costa Rica. II: Cacao and wood production, litter production and decomposition. Agroforestry Systems 6: 37-48.

IMBACH, AC; H.W. FASSBENDER; R. BOREL; J. BEER; A. kkBONNEMANN, 1989. Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) and cacao with poro (Erythrina poeppigiana) in Costa Rica. IV Water balances, nutrient imputs and leaching. Agroforestry Systems 8:267-287.

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