Article

Neglected pollinators: Can enhanced pollination services improve cocoa yields? A review

September 2017
Agriculture Ecosystems & Environment 247(1):137-148

DOI:10.1016/j.agee.2017.05.021

Authors:

Manuel Toledo-Hernández

Instituto Tecnológico Vale

Thomas C. Wanger

Westlake University

Teja Tscharntke

University of Göttingen

The negative effects of climate change on cocoa production are often enhanced through agricultural intensification, while research institutions and enterprises try to minimize yield gaps with production strategies mitigating climate risk. Ecological intensification is such a production strategy, whereby yield increase is promoted through reduced agrochemical inputs and increased regulating ecosystem services such as pollination. However, we still know little about cocoa pollination ecology and services, although they appear to be key to understand yield functions. Here, we provide an extensive literature review on cocoa pollination focusing on three main aspects: non-plant (external) and plant regulated (internal) factors affecting pollination, pollinator agents, and ecological intensification management for enhancing pollination success and yield. Pollination services by many arthropod groups such as ants, bees, and parasitic wasps, and not only ceratopogonids, may be a way to increase cocoa productivity and secure smallholders income, but their role is unknown. Several environmental and socioeconomic factors can blur potential pollination benefits. Current knowledge gaps preclude our understanding of how to (i) identify the major pollinator species, (ii) disentangle the direct or indirect role of ants in pollination, (iii) design effective habitat improvements for pollination (by litter and shade management), and (iv) quantify the yield gaps due to pollination limitation. Optimizing cocoa pollination alone appears to be a powerful ecological tool to increase the yield of smallholders, but experimental research is required to validate these results in a realistic setting. In general, industry, governments and smallholders need to develop more joined efforts to ecological production strategies. In particular, farm-base management innovations based on robust scientific evidence must be designed to meet the increasing demand for chocolate and to mitigate cocoa yield gaps. This review suggests that diversified systems and associated ecosystem services, such as pollination, can help to achieve such goals.

Global chocolate supply is limited by low pollination and high temperatures

Article

Full-text available

Feb 2025

Cocoa (Theobroma cacao L.) provides livelihoods for 5 million smallholder farmers, but the factors limiting cocoa yield are poorly understood. We present a global analysis of pollination, cocoa tree, plantation, and climate factors affecting cocoa yield, with experimental data from three major cocoa-producing countries: Brazil, Ghana and Indonesia. Hand-pollination increased yield by 20%, showing cocoa yield is limited by pollination, but not nutrients. Leaf litter and large cacao trees, measures of soil resource availability and access, increased yield by 9-19%. Cooler temperatures by 7 °C during the hot season increased yield by up to 31%, indicating substantial risks from climate warming. Agricultural production that enhances cocoa pollinator abundance, protects soils, and mitigates climate risks will be the most effective way to secure global cocoa production and support livelihoods into the future.

Environmental Conservation Tropical forests and cocoa production: synergies and threats in the chocolate market

Article

Full-text available

Jan 2025

Cocoa is an important agricultural product that plays a crucial role in local communities in South America. In Brazil, it is traditionally grown in agroforestry systems, which are more sustainable and contribute to biodiversity conservation. However, the recent expansion of intensive monocultures in tropical forests poses significant threats to this activity. Using historical data on land use and cocoa productivity at the municipality level from Brazil's primary cocoa-producing states, we show that maintaining and restoring forest cover are positively correlated with cocoa productivity, particularly in areas with less anthropogenic disturbance. This highlights the dependence of cocoa production on ecosystem services. Recent data reveal that in municipalities where local agriculture is less reliant on cocoa, only larger farms have benefitted from increased forest cover, probably due to their greater dependence on fragments of natural habitat for ecosystem services. In municipalities that are more reliant on cocoa, the effects of forest cover were not detected, while strong negative effects of forest fragmentation were observed in both small-and large-scale farms. We emphasize the importance of preserving natural forests near cocoa plantations to optimize productivity in Amazon and Atlantic Forest agroforestry, especially in deforested areas.

Environmental Conservation Tropical forests and cocoa production: synergies and threats in the chocolate market

Article

Full-text available

Jan 2025
ENVIRON CONSERV

Ecology of entomological communities in cocoa flowers (Theobroma cacao L.) in the shade-grown system: harmonic interactions in pollination

Article

Full-text available

Oct 2024
AGROFOREST SYST

Theobroma cacao L. is a crop of global importance, whose various aspects are studied annually. However, the ecology of pollination, including the mechanisms of interaction between floral visitors and cacao, still lacks substantial understanding. This study aimed to inventory the entomological community in the shade-grown system, to assess their behaviour and ecological roles in flower interactions. Cocoa flowers and their visitors were observed during the period of floral receptivity after anthesis. Four insect visiting periods were evaluated: 6:00 am–09:00 am, 9:00 am–12:00 am, 12:00 am–3:00 pm and 3:00 pm–6:00 pm. Behaviour was observed to determine ecological roles. The most common communities of visitors to cocoa flowers were Hymenoptera (57%), Hemiptera (18%), Diptera (17%) and Coleoptera (8%). Principal Component Analysis (PCA) classified behaviour of foraging, especially among dipterans, which spent more time inside the flowers and, as they moved around, came into contact with the floral reproductive structures, becoming effective pollination agents during the period (I). The most common visitors to cocoa flowers in the shade were ants, aphids and flies with more active behaviours during the day, suggesting that the flowers' pollination mechanism may be less specialized, but with a diversity of active and efficient visitors to ensure reproduction of the plant. Forcipomyia sp. flies were frequent pollinators, while ants Crematogaster acuta were the most abundant and constant visitors, despite the long foraging period, mutualism with hemipterans was more evident. Cocoa production management strategies need to be rethought to maintain beneficial insects that are essential for pollination ecology.

Small Amazonian stingless bees: an opportunity for targeted cocoa pollination

Article

Full-text available

Aug 2024

Cocoa (Theobroma cacao) is a multi-billion-dollar business. This tropical crop strongly depends on animal pollination for fruit development and seed production. The lack or inefficiency of natural pollinators in cocoa plantations has driven farmers to search for alternatives, such as laborious pollination by hand. A so far untested alternative, which has received increasing attention during the past couple of years, is targeted crop pollination through managed social bees. However, owing to the smallness of the flowers of T. cacao as well as structural barriers that impede large insects to access the stigma, only tiny bees may be a viable option for targeted cocoa pollination. In the present study, we asked whether small stingless bees (Apidae, Meliponini) could come into consideration as managed cocoa crop-pollinators, especially in shadowy agroforests. Among the 188 meliponine species native to the Brazilian Amazon region, which comprises an important portion of the center of origin of T. cacao, we selected 52 species based on morphological criteria (intertegular distance ≤ 1.4 mm; body length: 2.2-6.0 mm). Important for cocoa production, some of these Meliponini have an ample geographic distribution, occurring both in the center of origin of T. cacao and beyond (centers of cocoa production in Brazil: Para: 35 spp., Bahia: 10 spp.). Presumably all species may be active at illuminance levels below those found in heavily shaded cocoa plantations, at least at times when anthers show full dehiscence and during maximum receptivity of the stigma. The bees' potential to forage under reduced light regimes is corroborated by the finding that between 20 and 60% of the naturally exploited food sources are understory vegetation, including herbs, subshrubs, shrubs, and lianas. Many of the selected Meliponini build their nests, at least facultatively, in tree cavities, which facilitates their transfer to rational hives and, hence, the use of managed colonies in directed crop pollination. Important next steps for validating the potential of these small stingless bees in targeted cocoa pollination should comprise detailed studies on their foraging behavior and olfactory learning capacities.

Birds and bats enhance yields in Afrotropical cacao agroforests only under high shade

Preprint

Full-text available

Jan 2024

Sub-Saharan Africa produces most of the Earth’s cacao. Although pests cause losses of hundreds of millions annually, the role of cacao pest suppressors remains unknown. We used an exclusion experiment to prevent access of bats and birds to cacao trees and quantified how their absence affected arthropod communities, herbivory, and crop yield. Overall, Mealybugs and other hemipteran pests were more abundant in exclosures. Under heavy shade (90%), cacao trees with vertebrate exclosures had 3.9 times fewer flowers and 3.2 times fewer large pods than control trees, corresponding to losses on average of

478 ha-1y-1. Under low shade cover (10%) however, the opposite pattern was evident: exclosures trees had 5.2 times more flowers and 3.7 times more large pods than control trees, corresponding to savings on average of

796 ha-1y-1. Our study demonstrates that the enormous potential of African bats and birds as pest suppressors is dependent on shade tree management.

3D pollination biology using micro‐computed tomography and geometric morphometrics in Theobroma cacao

Article

Full-text available

Oct 2023

Premise Imaging technologies that capture three‐dimensional (3D) variation in floral morphology at micro‐ and nano‐resolutions are increasingly accessible. In herkogamous flowers, such as those of Theobroma cacao , structural barriers between anthers and stigmas represent bottlenecks that restrict pollinator size and access to reproductive organs. To study the unresolved pollination biology of cacao, we present a novel application of micro‐computed tomography (micro‐CT) using floral dimensions to quantify pollinator functional size limits. Methods We generated micro‐CT data sets from field‐collected flowers and museum specimens of potential pollinators. To compare floral variation, we used 3D Slicer to place landmarks on the surface models and performed a geometric morphometric (GMM) analysis using geomorph R. We identified the petal side door (an opening between the petal hoods and filament) as the main bottleneck for pollinator access. We compared its mean dimensions with proposed pollinators to identify viable candidates. Results We identified three levels of likelihood for putative pollinators based on the number of morphological (body) dimensions that fit through the petal side door. We also found floral reward microstructures whose presence and location were previously unclear. Discussion Using micro‐CT and GMM to study the 3D pollination biology of cacao provides new evidence for predicting unknown pollinators. Incorporating geometry and floral rewards will strengthen plant–pollinator trait matching models for cacao and other species.

Hand pollination under shade trees triples cocoa yield in Brazil's agroforests

Article

May 2023
AGR ECOSYST ENVIRON

Agricultural diversification can enhance climate resilience, biodiversity conservation, and livelihood in global farming systems. Diverse agroforestry systems with cocoa have been shown to provide all these benefits, but the often-lower yields compared to monocultures limit agroforestry adoption by smallholder farmers. Cocoa yield is pollination-limited, and here, we quantified the effect of hand pollination in cocoa on fruit set, fruit abortion or cherelle wilt, pest and diseases, and number of mature fruits. Experiments were conducted in Bahia, Brazil, along a shade gradient from low [10-30%] to high [70-100%] canopy cover and with cocoa trees grafted with high-yielding varieties. We found on average 331% fruit set, and 300% mature fruit increase (i.e. ripe pods) per tree by enhancing pollination by hand as little as 10% of the flowers/tree, compared to the control (i.e. with only natural pollination). Fruit set, fruit losses, and mature fruit development linked to hand pollination was higher in low compared to highly shaded cocoa areas. We found 31% higher fruit set and 37% higher number of mature fruits in grafted than un-grafted trees. Further, when comparing efforts invested in hand pollination, minimum labor (~5 min/tree to pollinate 10-30% of the flowers/tree) led to a 871% fruit set and a 750% mature fruit increase under low canopy cover, and intermediate labor (~15 min/tree to pollinate 40-60% flowers/tree) to a 629% fruit set under high canopy cover. As ~5-15 min/tree hand pollination can substantially enhance fruit set and number of mature fruits in low as well as high shade management, we recommend performing hand pollination particularly in agroforests under 40-50% canopy cover to create win-win opportunities for high productivity and climate resilience. Future research should focus on the wide range of agroforestry, tree grafting and innovation strategies in all major production regions to capture the long-term variability of hand pollination as a basis to scale-up hand pollination for sustainable cocoa production globally.

Resolving the identity and breeding habitats of cryptic dipteran cacao flower visitors in a Neotropical cacao agroforestry system

Article

Full-text available

Mar 2023
BASIC APPL ECOL

Determining the main pollinators and the factors that control their abundance is a prerequisite for improving the production of many crops, including the globally important cash crop cacao (Theobroma cacao L.). Yet, the identity and the breeding habitats of cacao pollinators remain controversial since they are very difficult to identify morphologically due to their small size. It is known that tiny midges are involved in cacao pollination, but their diversity and ecology remain obscure. Here, we combined the collection of flower visitors, the use of emergence traps, and DNA barcoding to assess the diversity of dipteran cacao flower visitors and link them to five candidate breeding habitats in an agroforestry system in central Nicaragua. We detected 59 lineages of dipteran flower visitors, including Cecidomyiidae, Ceratopogonidae, Chironomidae, and Sciaridae, suggesting that dipteran cacao pollinator diversity may be much higher than previously assumed. Five lineages could be genetically traced back to specific breeding habitats. We conclude that the presented approach can be a promising tool to reliably delineate potential pollinator species and their breeding habitats, which can inform management strategies to promote cacao pollination.

Hand Pollination Under Shade Trees Triples Cocoa Yield in Brazil's Agroforests

Article

Jan 2023

Birds and bats enhance yields in Afrotropical cacao agroforests only under high tree-level shade cover

Article

Full-text available

Apr 2023
AGR ECOSYST ENVIRON

Central/West Africa is one of the most biodiverse regions on earth and one of the largest producers of cacao, producing about 68.4 % of the world's chocolate. Here, cacao pests and diseases can cause losses of

761 million annually. However, no studies from Africa have quantified the role of flying vertebrates as pest suppressors in cacao plantations. We used an exclusion experiment to prevent access of bats and birds to cacao trees for 12 months and quantified how their absence affected arthropod communities, herbivory, and cacao crop yield. Overall, important pests such as mealybugs and other hemipterans were more abundant in exclosures (9 and 1.6 times increase, respectively), despite potential multitrophic interactions with simultaneously increasing predatory arthropods such as spiders and mantis. Under heavy shade (90 %), cacao trees with flying vertebrate exclosures had 3.9 times fewer flowers and 3.2 times fewer large pods than control trees, corresponding to estimated losses on average of

478 ha⁻¹y⁻¹. Under low tree-level shade cover (10 %) however, the opposite pattern was evident: exclosure trees had 5.2 times more flowers and 3.7 times more large pods than control trees, corresponding to estimated savings on average of $796 ha⁻¹y⁻¹. We demonstrate that the enormous potential of African flying vertebrates as pest suppressors in cacao plantations is dependent on local shade tree management and only economically relevant above 50 % of shade. Despite higher productivity at low shade levels, our findings encourage African policymakers and farmers to adopt more high shade cacao agroforestry systems to maximize pest suppression services provided by bats and birds.

Tropical Forests and Cocoa Production: Synergies and Threats in the Chocolate Market

Article

Full-text available

Jan 2022

Cacao flower visitation: Low pollen deposition, low fruit set and dominance of herbivores

Article

Full-text available

Apr 2022

Pollination services of cacao are crucial for global chocolate production, yet remain critically understudied, particularly in regions of origin of the species. Notably, uncertainties remain concerning the identity of cacao pollinators, the influence of landscape (forest distance) and management (shade cover) on flower visitation and the role of pollen deposition in limiting fruit set. Here, we aimed to improve understanding of cacao pollination by studying limiting factors of fruit set in Peru, part of the centre of origin of cacao. Flower visitors were sampled with sticky insect glue in 20 cacao agroforests in two biogeographically distinct regions of Peru, across gradients of shade cover and forest distance. Further, we assessed pollen quantities and compared fruit set between naturally and manually pollinated flowers. The most abundant flower visitors were aphids, ants and thrips in the north and thrips, midges and parasitoid wasps in the south of Peru. We present some evidence of increasing visitation rates from medium to high shade (40%–95% canopy closure) in the dry north, and opposite patterns in the semi‐humid south, during the wet season. Natural pollination resulted in remarkably low fruit set rates (2%), and very low pollen deposition. After hand pollination, fruit set more than tripled (7%), but was still low. The diversity and high relative abundances of herbivore flower visitors limit our ability to draw conclusions on the functional role of different flower visitors. The remarkably low fruit set of naturally and even hand pollinated flowers indicates that other unaddressed factors limit cacao fruit production. Such factors could be, amongst others, a lack of effective pollinators, genetic incompatibility or resource limitation. Revealing efficient pollinator species and other causes of low fruit set rates is therefore key to establish location‐specific management strategies and develop high yielding native cacao agroforestry systems in regions of origin of cacao.

Cocoa pollination, biodiversity-friendly production, and the global market

Preprint

Full-text available

Dec 2021

Production of cocoa, the third largest trade commodity globally has experienced climate related yield stagnation since 2016, forcing farmers to expand production in forested habitats and to shift from nature friendly agroforestry systems to intensive monocultures. The goal for future large-scale cocoa production combines high yields with biodiversity friendly management into a climate adapted smart agroforestry system (SAS). As pollination limitation is a key driver of global production, we use data of more than 150,000 cocoa farms and results of hand pollination experiments to show that manually enhancing cocoa pollination (hereafter manual pollination) can produce SAS. Manual pollination can triple farm yields and double farmers annual profit in the major producer countries Ivory Coast, Ghana, and Indonesia, and can increase global cocoa supplies by up to 13%. We propose a win win scenario to mitigate negative long term price and socioeconomic effects, whereby manual pollination compensates only for yield losses resulting from climate and disease related decreases in production area and conversion of monocultures into agroforestry systems. Our results highlight that yields in biodiversity friendly and climate adapted SAS can be similar to yields currently only achieved in monocultures. Adoption of manual pollination could be achieved through wider implementation of ecocertification standards, carbon markets, and zero deforestation pledges.

Fostering pollination through agroforestry: A global review

Article

Aug 2023
AGR ECOSYST ENVIRON

Cross-pollination with native genotypes improves fruit set and yield quality of Peruvian cacao

Article

Jul 2023
AGR ECOSYST ENVIRON

XXX download here: https://authors.elsevier.com/a/1hTtNcA-Inxce XXXX The cacao tree (Theobroma cacao) is a billion-dollar crop species of which the yields are greatly constrained by, amongst others, pollination limitation. Manual pollen supplementation has been proposed to counter pollination deficits, thus improving yield quantity and potentially also quality, as the origin of the pollen can be controlled. In native cacao, low self-and cross-compatibility rates and the interaction with abiotic growth conditions are expected to limit manual pollination benefits. Here we compared supplementation of self-pollen with cross-pollen of five native genotypes selected for their sensorial quality as pollen donors. Simultaneously, we assessed how temperature, relative air humidity and soil water content influenced fruit set and evaluated qualitative differences between pollen-supplemented and open pollinated fruits. Success of manual self-pollination was very low (0.5 %) but increased 3-8-fold in cross-pollination experiments. Cross-pollination success rates depended on the genotype of the pollen donor, irrespective of genetic distance between pollen donor and recipient. Further, seed weight and premium seed content was higher in fruits resulting from pollen-supplemented than from open-pollinated flowers. Fruit set was also affected by the interaction of temperature and relative humidity, but not by soil water content. Together, our findings suggest that reproductive traits of native cacao systems are constrained by genetic compatibility and some abiotic factors. Even though manual pollen supplementation with native genotypes can clearly benefit both fruit quantity and quality, it is labor intensive and hence costly to implement. Natural cross-pollination by planting compatible genotypes selected for sensorial quality could simultaneously avoid high costs and improve fruit quality, potentially resulting in net economic gains for smallholder farmers.

Managing insect services and disservices in cocoa agroforestry systems

Article

Full-text available

Mar 2023
AGROFOREST SYST

Ecological role of insects in cocoa agroforestry systems is a key component of biodiversity that generally underlines what insects do in cocoa agroforestry systems. Although insects are often under-appreciated and viewed by many cocoa farmers as a nuisance and pests, they provide a diversity of ecosystem services in cocoa agroforestry systems. Farm management practices affect the role and function of these insects, and consequently the ecosystem services and disservices they provide. This paper reviews the importance of insects in cocoa agroforestry systems and examines five major ecosystem service that insects provide. It also highlights farm management practices that affect ecosystem services and disservices provided by insects in cocoa agroforestry systems. The paper further summarizes some of the major and minor insect pest species that can be found in cocoa agroforestry systems, the damages they cause, as well as their management strategies. The conclusion provides insight on how to conserve valuable ecosystem services provided by insects in cocoa agroforestry systems, suggests innovative farm management practices to reduce disservices provided by some insect pest species, and offers recommendations for future research.

Farmers’ knowledge and practices on pollination and insecticide use in cocoa farming in Ghana

Article

Aug 2022

Although evidence of the limiting role of pollination in cocoa production is mounting, concern about the potential harm of insecticides to pollinators is also increasing. However, effort at examining farmer knowledge and practices on pollination and insecticide use aimed at promoting cocoa pollination is limited. This study assessed farmers' knowledge and practices on pollination and insecticide usage in four cocoa-growing communities (two organic and two conventional) in the Eastern region of Ghana. Data from interviewing cocoa farmers (200) with a structured questionnaire were analysed using various statistical techniques. Less than 50% of the farmers had knowledge of pollination and its influence on yield. Only 1% of the respondents identified midges as pollinators of cocoa, while 11% and 19.5% identified honey bees and ants as pollinator agents, respectively. Less than 50% of respondents believed insecticide application might impact on beneficial insects, including pollinators. Farmers’ responses were highly influenced by farming system, educational background, farmer groups and extension officers. Our findings show that educating smallholder farmers on pollination and judicious insecticide use is crucial in improving long-term cocoa yields. These findings have implications for pest management policies and farmer sensitization on the impact of indiscriminate insecticide application on the environment and pollinators. KEYWORDS: Cocoa farming, cocoa, pollination, farming systems, insecticides, midges, Ghana.

Landscape forest cover and regional context shape the conservation value of shaded cocoa agroforests for bees and social wasps

Article

Full-text available

Nov 2024
LANDSCAPE ECOL

Context The expansion of agricultural lands threatens biodiversity maintenance across the tropics. Although some agroforestry systems may be biodiversity-friendly, their conservation value likely depends on the landscape and regional contexts in which they are embedded—a poorly tested hypothesis. Objectives We assessed the conservation value of shaded cocoa agroforests for bees and social wasps, and evaluated whether such value depends on the remaining forest cover at the landscape and/or regional scales. Methods Using a paired design, we compared α- (species number) and β-diversity of each taxon between cocoa agroforests and neighbouring rainforests in 30 landscapes from three regions with different deforestation levels from the Brazilian Atlantic Forest. We assessed whether the species number ratio (cocoa/forest) and β-diversity related to landscape-scale forest cover, and whether such a relationship differed among regions (interacting effect). Results Cocoa agroforests held more bee and wasp species than forests, and β-diversity between habitats was moderate (bees) to high (wasps). Bees’ species number ratio peaked at the intermediate-deforested region, and β-diversity decreased with increasing forest cover, indicating that both land uses shared more species in more forested landscapes, especially in the high- and intermediate-deforested regions. Yet, for social wasps, β-diversity varied only within regions, with habitats sharing more species in the low-deforested region. Conclusions Our findings highlight that the conservation value of shaded cocoa agroforests for bees and social wasps depends on local and regional landscape forest cover. With cocoa agroforest being highly permeable matrix which increases with higher forest cover especially for bees in high- and intermediate-deforested regions.

The Role of Big Data and CNNs in Cocoa Disease Management

Book

Full-text available

Jul 2024

Atianashie Miracle A.

The Role of Big Data and CNNs in Cocoa Disease Management is a comprehensive book that explores the integration of advanced technologies in agriculture, focusing on cocoa farming. It is an important work exploring how Big Data analytics and Convolutional Neural Networks (CNNs) can revolutionize how cocoa diseases are detected, managed, and prevented. The book is structured to systematically explore cocoa farmers' challenges, including pest infestations, diseases, environmental concerns, and market volatility. It then introduces the transformative potential of Big Data and CNNs in addressing these issues. With a narrative enriched by real-world case studies and practical applications, it provides readers with insights into the successful implementation of technology in the field. Targeted at a diverse readership, including cocoa farmers, agronomists, researchers, students, policymakers, technology developers, and innovators, the book is an invaluable resource for those seeking practical solutions to enhance crop yield and disease management, as well as for those interested in the intersection of agriculture and cutting-edge technology. The author, Miracle A. Atianashie, offers a forward-looking discussion on future trends and potential innovations in agriculture technology, inviting readers to contemplate the evolving trajectory of the sector. As a guide and source of inspiration, "The Role of Big Data and CNNs in Cocoa Disease Management" should be read sequentially, as each chapter builds upon the previous, crafting a coherent narrative that deepens the reader's understanding of the subject matter.

Animal‐pollinated crops and cultivars—A quantitative assessment of pollinator dependence values and evaluation of methodological approaches

Article

Full-text available

Apr 2024
J APPL ECOL

Crop pollinator dependence (PD) values are key when assessing a pollinator's contribution to agriculture, guiding management plans and policies for sustainable crop production. However, the available global compilations of crops PD are outdated and neglect variability between related crops and accessions (variety/cultivar), as well as pollen limitation (PL), that is the production lost due to inadequate pollen receipt. Here, we obtained quantitative PD values for animal‐pollinated crops and their accessions, using data from available pollination experiments worldwide. We also tested pollination methodologies to assess their impact on PD values and to define suitable methodological guidelines for future pollination studies. We provide a list of continuous PD values for 141 crops, including 317 accessions and 37 crops not listed in previous assessments. We found that, globally, 74% of animal‐pollinated crops are highly dependent on pollinators, and more than 40% of their production is associated with animal pollination. Pollen limitation was detected in 51% of the dataset entries, indicating that estimates calculated with open pollination studies underestimate crop pollinator dependence and, therefore, do not represent the true contribution of pollinators to food production. Synthesis and applications: Commonly applied methods for assessing PD values can lead to underestimations. Future studies evaluating pollinator dependence levels of crops and their accessions (i.e. potential pollinator contribution) should consider the possibility of pollen limitation in the study site, incorporating hand pollen supplementation (to open flower), open pollination, and pollinator exclusion treatments, preferably using the whole plant or branch as the unit of assessment. The PD values provided here, from studies that allow the incorporation of the concept of pollen limitation, enable more accurate quantifications of pollinator contribution to crop production. These PD values are an invaluable baseline and a requirement for future accurate evaluations of the value of pollinators for food security, supporting pollinator‐friendly practices in agroecosystems.

Avoidance of tree-site mismatching of modelled cacao production systems across climatic zones: Roots for multifunctionality

Article

Apr 2024
AGR SYST

CONTEXT: Protective roles of shade trees for climate-resilient cacao appear to depend on tree-site matching. Agroforestry practices involve a wide range of context-specific management options, which can be complex and pose challenges due to tradeoffs. OBJECTIVE: To assess the benefits and drawbacks, across a range of contexts, of various cacao-based land use systems on multifunctionality and economic performance. METHODS: We used the process-based Water, Nutrient and Light Capture in agroforestry systems (WaNuLCAS) model to assess the performance of five cacao-based land use systems (cacao monoculture, cacao + annual crops, cacao + fruit tree, cacao + fast-growing tree, and cacao + slow-growing tree), in three climate regimes (tropical rainforest, monsoon, and savannah), two soil textures, and two sources of data for cacao root length density (W Africa and Indonesia, respectively). Several metrics quantified the performance of each land use system, including the Land Equivalent Ratio for production (LERP),multifunctionality (LERM), Net Present Value (NPV), Return to Labour (RtL), and Benefit-Cost Ratio (BCR). RESULTS AND CONCLUSIONS: Simulated cacao production per tree, positively or negatively influenced by intercrops, responded to the number of days cacao grew under water-limited conditions. High cacao root density supported higher LERP values (an average of 1.15 versus 0.95 in other cases). In the savanna, the LERP difference between cacao with high root density and those with low root density became 0.27. Among agroforestry systems, cacao + annual crops had the highest LERP of 1.13, followed by cacao + slow-growing trees (1.09), while the lowest outcome (0.98) was for cacao + fruit trees. These values were higher in rainforest climates, and lowest for savanna. Soil texture had no effect on the average LERP across other main factors. Tree-based agroforestry had a higher time-averaged carbon stock than monocultures or systems with annual crops. However, their effects on other environmental performance aspects, averaged over a 20-year life cycle, were modest, and variation in LERM was small. Economic performance indicators diverged, with the highest NPV were for cacao + annual crops or cacao + fruit trees, the highest BCR was for cacao + fruit trees, and the highest RtL was for cacao + fruit trees followed by cacao + slow-growing trees. SIGNIFICANCE: Our study highlights that the potential benefits of cacao-based agroforestry practices depend on strong root development by the cacao trees. In selecting for high yields in monocultures, the benefits of intercropping may be forfeited, especially in drier climates with the lower values for root length density measured in W Africa.

A phylogenetic framework to study desirable traits in the wild relatives of Theobroma cacao (Malvaceae)

Article

Full-text available

Feb 2024

Crop wild relatives (CWRs) of cultivated species may provide a source of genetic variation that can contribute to improving product quantity and quality. To adequately use these potential resources, it is useful to understand how CWRs are related to the cultivated species and to each other to determine how key crop traits have evolved and discover potentially usable genetic information. The chocolate industry is expanding and yet is under threat from a variety of causes, including pathogens and climate change. Theobroma cacao L. (Malvaceae), the source of chocolate, is a representative of the tribe Theobromateae that consists of four genera and c. 40 species that began to diversify over 25 million years ago. The great diversity within the tribe suggests that its representatives could exhibit advantageous agronomic traits. In this study, we present the most taxonomically comprehensive phylogeny of Theobromateae to date. DNA sequence data from WRKY genes were assembled into a matrix that included 56 morphological characters and analyzed using a Bayesian approach. The inclusion of a morphological data set increased resolution and support for some branches of the phylogenetic tree. The evolutionary trajectory of selected morphological characters was reconstructed onto the phylogeny. This phylogeny provides a framework for the study of morphological and physiological trait evolution, which can facilitate the search for agronomically relevant traits.

Coupling remote sensing and eDNA to monitor environmental impact: A pilot to quantify the environmental benefits of sustainable agriculture in the Brazilian Amazon

Article

Full-text available

Feb 2024
PLOS ONE

Monitoring is essential to ensure that environmental goals are being achieved, including those of sustainable agriculture. Growing interest in environmental monitoring provides an opportunity to improve monitoring practices. Approaches that directly monitor land cover change and biodiversity annually by coupling the wall-to-wall coverage from remote sensing and the site-specific community composition from environmental DNA (eDNA) can provide timely, relevant results for parties interested in the success of sustainable agricultural practices. To ensure that the measured impacts are due to the environmental projects and not exogenous factors, sites where projects have been implemented should be benchmarked against counterfactuals (no project) and control (natural habitat) sites. Results can then be used to calculate diverse sets of indicators customized to monitor different projects. Here, we report on our experience developing and applying one such approach to assess the impact of shaded cocoa projects implemented by the Instituto de Manejo e Certificação Florestal e Agrícola (IMAFLORA) near São Félix do Xingu, in Pará, Brazil. We used the Continuous Degradation Detection (CODED) and LandTrendr algorithms to create a remote sensing-based assessment of forest disturbance and regeneration, estimate carbon sequestration, and changes in essential habitats. We coupled these remote sensing methods with eDNA analyses using arthropod-targeted primers by collecting soil samples from intervention and counterfactual pasture field sites and a control secondary forest. We used a custom set of indicators from the pilot application of a coupled monitoring framework called TerraBio. Our results suggest that, due to IMAFLORA’s shaded cocoa projects, over 400 acres were restored in the intervention area and the community composition of arthropods in shaded cocoa is closer to second-growth forests than that of pastures. In reviewing the coupled approach, we found multiple aspects worked well, and we conclude by presenting multiple lessons learned.

Los insectos y la polinización: un servicio ecosistémico vital

Article

Full-text available

Jun 2023

Isabel Kilian

Los insectos son el grupo de animales más diverso del mundo y son capaces de proporcionar diferentes servicios ecosistémicos, entre ellos la polinización. Durante este proceso, los insectos suelen visitar las flores en busca de alimento (polen y néctar) o alguna otra recompensa (generalmente aceites y esencias) y terminan transportando el polen de una antera de una flor al estigma de otra facilitando la fertilización y reproducción de las Angiospermas. En los ecosistemas agrícolas, cerca del 75% de las plantas con importancia económica mundial, entre ellas frutales, nueces, café, cacao e vainilla dependen directamente de la polinización, siendo los himenópteros (abejas, avispas y hormigas), los dípteros (mosquitos y moscas) y los coleópteros (escarabajos) las ordenes que incluyen la mayoría de especies polinizadoras. A pesar de su papel esencial en este proceso, la diversidad de muchos insectos es ampliamente desconocida al igual que su función como agentes de polinización, con relación a su eficiencia, fidelidad floral, frecuencias y/o rutas adecuadas de visitas a las flores. Un agravante adicional en la falta de información en muchos grupos de insectos polinizadores, son las presiones antropogénicas actuales como los cambios en el uso del suelo, las prácticas agrícolas y el cambio climático. Así, muchas especies de insectos pueden desaparecer incluso antes que información básica sobre ellos pueda ser generada.

Factores asociados a la polinización del cultivo de cacao (Theobroma cacao L.)

Article

Full-text available

Jul 2023

Introducción. La polinización es importante en gran parte de los sistemas productivos mundiales, tal es el caso del cultivo de cacao (Theobroma cacao L.), el cual depende de la actividad de los insectos para su polinización. Objetivo. Recopilar las investigaciones más relevantes que incluyen los factores determinantes en la polinización del cultivo de cacao. Desarrollo. El presente trabajo fue realizado entre 2021 y 2022, con una búsqueda exhaustiva de bibliografía relacionada con la polinización y polinizadores del cultivo de cacao, en artículos científicos, en español, inglés y portugués. La información de obtuvo a partir de bases de datos, repositorios de universidades, revistas de investigación y bibliotecas agropecuarias digitales. La polinización del cultivo de cacao se atribuye a dípteros de la familia Ceratopogonidae, del género Forcipomyia sp, que se observan con mayor abundancia en época lluviosa. La presencia del insecto se ha relacionado con materiales en descomposición presentes en la cobertura del suelo, por su hábito reproductivo, por lo que se considera importante proporcionar refugios con humedad para que las larvas del polinizador puedan desarrollarse. Conclusiones. Comprender las dinámicas de polinización del cacao y los factores que la afectan es esencial para conservar y aumentar los rendimientos de los cultivos, así como los ingresos de los agricultores del mundo. Además, en el cultivo de cacao existen factores bióticos, como la presencia de polinizadores, clones utilizados y arreglos forestales, y factores abióticos, como la precipitación, temperatura, radiación y la cobertura del suelo, que marcan una pauta inicial a tener en cuenta en los sistemas productivos.

Birds and bats enhance cacao yield despite suppressing arthropod mesopredation

Article

Full-text available

May 2023
ECOL APPL

Bird‐ and bat‐mediated biocontrol benefits the productivity of tropical commodity crops such as cacao, but the ecological interactions driving these ecosystem services remain poorly understood. Whereas birds and bats prey on herbivorous arthropods, they may also prey on arthropod mesopredators such as ants, with poorly understood consequences for pest biocontrol. We used a full‐factorial experiment excluding birds, bats, and ants to assess their effects on (a) the abundance of multiple arthropod groups; (b) predation pressure on arthropods evaluated through artificial sentinel caterpillars; and (c) cacao yield over 1 year in shaded agroforestry systems of native cacao varieties in Peru. Birds and bats increased cacao yield by 118%, which translates in smallholder benefits of ca. US $959 ha⁻¹ year⁻¹. Birds and bats decreased predation by ants and other arthropods, but contributed to the control of phytophagous taxa such as aphids and mealybugs. By contrast, ant presence increased the abundance of these sap‐sucking insects, with negative impacts for cacao yield. Notably, high abundances of the dominant ant Nylanderia sp., known to attend sap‐sucking insects, were associated with lower cacao yield along a distance gradient from the closest forest edge. According to these results, arthropod predation by birds and bats, rather than mesopredation by arthropods, was most responsible for increases in cacao yield. Moving forward, detailed research about their trophic interactions will be necessary to identify the cause of such benefits. Retaining and restoring the large benefits of birds and bats as well as minimizing disservices by other taxa in cacao agroforests can benefit from management schemes that prioritize preservation of shade trees and adjacent forests within agroforestry landscapes.

Pollinator Dependence values of animal-pollinated crops – an updated compilation and discussion on methodological approaches

Preprint

Full-text available

Mar 2023

Pollinator dependence (PD) of a crop is a key estimate for assessing nature’s contribution to agriculture. However, currently available global compilations of crops PD are outdated and neglect variability between accessions (variety/cultivar) and information on pollen deposition limitation. Here we provide an updated list of PD values for 116 pollinator-dependent crops, including 284 crop accessions and 33 crops not listed in previous assessments. We found that, globally, 80% (instead of less than 50% indicated in previous works) of animal-pollinated crops depend highly on pollinators. Pollen deposition limitation was detected in 52% of the dataset entries, indicating that the pollinator community in those cases was insufficient to fully provide the pollination service. Given that most published studies on the PD of crops are solely based on natural pollination levels, the contribution of pollinators to most crops is underestimated. Pollen supplementation treatments should hence be incorporated into future studies. This study provides valuable data for future evaluations of the pollinator’s importance for human well-being as well as guidelines for future crop pollination studies.

Modelo de gestión estratégica para el posicionamiento comercial en el mercado internacional del cacao Amazonas, Perú

Article

Apr 2019

Esta investigación propone un modelo de gestión estratégica que permita mejorar el posicionamiento comercial en el mercado internacional del cacao Amazonas Perú, la investigación fue descriptiva propositiva. Se utilizaron datos de encuestas originales en 100 fincas cacaoteras en las provincias de Bagua y Utcubamba en la Región Amazonas, que caracterizaron el cultivo de cacao y las principales variables socioeconómicas. Además se aplicó una entrevista a los gerentes de las organizaciones de productores y al Director de la Mesa Técnica Regional de Cacao con la finalidad de diagnosticar el mercado objetivo. Para el análisis interno y externo se utilizó la matriz FODA. Con estos datos se construyó un vector de crecimiento de oportunidades con ayuda de la Matriz Ansoff. Finalmente, las opciones estratégicas identificadas se sistematizaron en un modelo de gestión. El modelo generado propone estrategias de penetración en los mercados, desarrollo de productos y mercados y diversificación, que coadyuvarán al futuro desarrollo de las organizaciones productoras de cacao.

North America

Chapter

Oct 2022

Since AR5, climate-change impacts have become more frequent, intense and have affected many millions of people from every region and sector across North America (Canada, USA and Mexico). Accelerating climate-change hazards pose significant risks to the well-being of North American populations and the natural, managed and human systems on which they depend (high confidence1). Addressing these risks has been made more urgent by delays due to misinformation about climate science that has sowed uncertainty and impeded recognition of risk (high confidence). {14.2, 14.3} Without limiting warming to 1.5°C, key risks to North America are expected to intensify rapidly by mid-century (high confidence). These risks will result in irreversible changes to ecosystems, mounting damages to infrastructure and housing, stress on economic sectors, disruption of livelihoods, and issues with mental and physical health, leisure and safety. Immediate, widespread and coordinated implementation of adaptation measures aimed at reducing risks and focused on equity have the greatest potential to maintain and improve the quality of life for North Americans, ensure sustainable livelihoods and protect the long-term biodiversity, and ecological and economic productivity, in North America (high confidence). Enhanced sharing of resources and tools for adaptation across economic, social, cultural and national entities enables more effective short- and long-term responses to climate change. {14.2, 14.4, 14.5, 14.6, 14.7}

NUMBER OF POLLEN GRAINS, OVULES AND POLLEN-OVULE RATIO IN CACAO CLONES

Article

Aug 2022

Ceratopogonidae: their role in pollination and fertilization at various technological levels of Theobroma cacao L. production

Article

Full-text available

Aug 2022

The goal of this study was to evaluate the role of pollinators on the pollination, fertilization and fruit set process in three technological production levels and three reproduction substrates, determinants in cocoa yield. Two pollination techniques (natural and assisted) were compared and as a control, flowers were isolated with antiaphid. Twenty-seven observation units were formed, with three biological replicates. A known number of flowers were evaluated 6, 14, 21 and 36 days after the opening of each flower on marked branches. The number of active flowers, pollinated, fertilized and fruits formed was recorded. Pollinators present in experimental units were collected using yellow sticky cards, then taken to the lab and identified. Pollination occurred up to three days after opening, the flower that remained with the ovary swollen and attached to the branch/stem was considered pollinated. Fertilization was recorded fourteen days after flower opening, fruit set begins after fertilization, an event that was quantified twenty-one days after flower opening. The systems studied did not influence the percentage of pollination, fertilization and fruit formation. However, the substrates did influence pollination, fertilization and fruit set. The assisted pollination technique is significantly superior to natural pollination. The same species of Ceratopogonidae were reported at all three levels and substrates, with genera Forcipomyia and Dasyhelea being the most abundant.

Cacao farming for peace building and rural development. Socioeconomic Programme: Report 4 GROW Colombia Project.

Technical Report

Full-text available

Mar 2022

The Matthew effect: Common species become more common and rare ones become more rare in response to artificial light at night

Article

Full-text available

Feb 2022

Artificial light at night (ALAN) has been and still is rapidly spreading, and has become an important component of global change. Although numerous studies have tested its potential biological and ecological impacts on animals, very few studies have tested whether it affects alien and native plants differently. Furthermore, common plant species, and particularly common alien species, are often found to benefit more from additional resources than rare native and rare alien species. Whether this is also the case with regard to increasing light due to ALAN is still unknown. Here, we tested how ALAN affected the performance of common and rare alien and native plant species in Germany directly, and indirectly via flying insects. We grew five common alien, six rare alien, five common native and four rare native plant species under four combinations of two ALAN (no ALAN vs ALAN) and two insect‐exclusion (no exclusion vs exclusion) treatments, and compared their biomass production. We found that common plant species, irrespective of their origin, produced significantly more biomass than rare species, and that this was particularly true under ALAN. Furthermore, alien species tended to show a slightly stronger positive response to ALAN than native species did (p = 0.079). Our study shows that common plant species benefited more from ALAN than rare ones. This might lead to competitive exclusion of rare species, which could have cascading impacts on other trophic levels and thus have important community‐wide consequences, when ALAN becomes more widespread. In addition, the slightly more positive response of alien species indicates that ALAN might increase the risk of alien plant invasions.

Balancing litterfall and decomposition in cacao agroforestry systems

Article

Full-text available

Apr 2022
PLANT SOIL

Backgrounds and aims Litter protects the underlying soil, depending on litterfall and decomposition, but dynamics of the standing litter stock in agroforestry systems remain poorly understood. We aimed to unravel effects of litter quality, temporal patterns, microclimate, and a possible home-field advantage (HFA) on standing litter dynamics across a land-use gradient. Methods We quantified litterfall, the standing litter stock, and microclimate during a year in (remnant) forest, cacao-based simple and complex agroforestry, cacao monocultures, and annual crops in a cacao producing area in Indonesia. We conducted a reciprocal litter transfer experiment, and tested decomposition rates of pruning residues. Standing litter stocks during the year were estimated from monthly litterfall and decomposition rates. Results Variation in litter quality influenced decomposition rates more strongly than variation in microclimate or HFA. Lower litter quality in complex agroforestry and in the cacao monoculture decreased the decay rate compared to simple agroforestry systems; mean litter residence time was over a year. Mixing high- and low-quality material in pruning residues modified the decomposition rate, soil C and N changes, offering options for targeted management of soil protection and nutrient release. Conclusions The seasonal patterns of litterfall and relatively slow decomposition rates supported permanence of the litter layer in all cacao production systems, protecting the underlying soil.

Biodiversity Conservation Potential of Forests and Trees On Farms In the Agricultural–Forest Mosaic Landscape of Catacamas, Honduras

Preprint

Full-text available

Dec 2021

Biodiversity decline in the tropics requires the implementation of comprehensive landscape management where agricultural systems are necessarily an integral element of biodiversity conservation. This study evaluates the potential for biodiversity conservation within an intensive livestock-agricultural-forest mosaic landscape in Catacamas, Honduras. Tree sampling was performed in 448 plots set up within different forest and agricultural land uses: secondary forests, agroforestry coffee plantations, agriculture, pastures, live fences and riparian forest. All trees with a minimum diameter at breast height of 10 cm were identified and measured. We characterized their tree structure and diversity, and compared tree diversity between the different uses. The results indicate a high degree of tree species diversity: 375 species identified, belonging to 74 families among the 15,096 trees inventoried across 84.2 hectares, including many rare species (40% of the species registered three individuals or fewer). Biodiversity indices for agroforestry coffee were found equivalent to those for natural secondary forests in the Catacamas landscape. Combining biodiversity conservation and agricultural production is possible in human-pressured tropical landscapes through tree cover maintenance. Enrichment practices combining local producers and technical knowledge may improve tree diversity in agricultural landscapes by prioritizing a mix of forest and introduced tree species (rare and with multiple uses).

Trait-dependent responses of birds and bats to season and dry forest distance in tropical agroforestry

Article

Feb 2022
AGR ECOSYST ENVIRON

Agricultural expansion and intensification increasingly threaten birds and bats, especially insectivorous species from the tropics. Cacao agroforests in tropical rainforest areas have been shown to support higher bird and bat biodiversity than other land-use systems, but their suitability for tropical dry forest biodiversity remains unclear. We present the first assessment of bird and bat diversity patterns in cacao agroforests inside tropical dry forest landscapes. We investigated the response of bird and bat species richness and abundance to forest distance and season across 12 smallholder, organic cacao agroforests and adjacent tropical dry forests in the Peruvian lowlands of Piura. We found that insectivorous bird abundance and species richness increased with forest distance in the dry but not in the rainy season, indicating the value of cacao agroforests for these birds when resources are scarce in forests. In the case of bats, we observed more species in agroforests with increasing forest distance independent of season, and the abundance of insectivorous species increased along the gradient. Other dietary groups and forest specialists of both taxa did not vary notably across the forest distance gradient. Our findings point to the relevance of cacao agroforests as alternative habitats for insectivorous birds and bats in tropical dry forest landscapes, especially during the dry season. We suggest that the maintenance of wildlife friendly cacao agroforests, parallel to dry forest conservation and restoration, creates win-win situations for both the conservation of tropical dry forest fauna and the maintenance of related ecosystem services from which cacao smallholders may benefit.

Hand pollination of global crops – A systematic review

Article

Aug 2021
BASIC APPL ECOL

Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production.

Spatial analysis of drought vulnerability in cocoa agroforestry systems across the Ghana-Togo border

Article

Full-text available

Feb 2025

Extreme events like droughts frequently affect West Africa, known as the world’s centre for cocoa production. In Ghana and Togo, these extreme events negatively affect water supplies and agricultural land productivity, especially for cocoa. This study aims to create a cocoa drought vulnerability map that offers a clearer perspective of drought effects over the transboundary territory between Ghana and Togo, where substantial amounts of cocoa are produced. The vulnerability map used 16 criteria categorised under three (3) vulnerability components Exposure [4], Sensitivity [6], and Adaptive Capacity [6]. The study used the Intergovernmental Panel on Climate Change (IPCC) vulnerability framework and the Analytical Hierarchy Process (AHP) to normalise the criteria. Results showed that over 70% of the cocoa cultivation area in the study area is moderately to highly vulnerable to drought, while less than 30% is classified as very low and low. The most susceptible areas are located on the Togolese side, extending from the central to the northern region, compared to Ghana. These findings are relevant to support drought resilience strategies in the cocoa sector aiming to prioritise interventions and maximise cocoa productivity per drought vulnerability category zone.

Identifying Cocoa Pollinators: A Deep Learning Dataset

Preprint

Full-text available

Dec 2024

Cocoa is a multi-billion-dollar industry but research on improving yields through pollination remains limited. New embedded hardware and AI-based data analysis is advancing information on cocoa flower visitors, their identity and implications for yields. We present the first cocoa flower visitor dataset containing 5,792 images of Ceratopogonidae, Formicidae, Aphididae, Araneae, and Encyrtidae, and 1,082 background cocoa flower images. This dataset was curated from 23 million images collected over two years by embedded cameras in cocoa plantations in Hainan province, China. We exemplify the use of the dataset with different sizes of YOLOv8 models and by progressively increasing the background image ratio in the training set to identify the best-performing model. The medium-sized YOLOv8 model achieved the best results with 8% background images (F1 Score of 0.71, mAP50 of 0.70). Overall, this dataset is useful to compare the performance of deep learning model architectures on images with low contrast images and difficult detection targets. The data can support future efforts to advance sustainable cocoa production through pollination monitoring projects.

Valuing Pollination as an Ecosystem Services: The Case of Hand Pollination for Cocoa Production in Ghana

Article

Full-text available

Dec 2024

The promotion of cocoa farm productivity has necessitated the intensification of input use with ensuing loss of natural pollinators. Ghana Cocoa Board’s (COCOBOD) remedy to declining pollinator population is addressed in the rolling out of hand pollination in the 2016/17 crop year. Applying contingent valuation on field data covering 608 farmers in five cocoa growing regions, we estimate the value of pollinator services to the cocoa industry in Ghana and farmers willingness to pay for the service. We find that cocoa farmers in Ghana are willing to pay for hand pollination to improve on their farm yields. Farmers averagely value pollinator services at

1.3 per acre of land. Extrapolated to cover all cultivated cocoa lands for 2017/18 crop year, the value of pollinator services to Ghana’s cocoa industry is averagely

6.1 million per annum. Hand pollination can improve cocoa farms yields given the statistically significant mean difference in yields between hand-pollinated and non-hand-pollinated farms. Having established the loss to the cocoa industry from pollinator decline and the need for effective pollination to support crop productivity, it is imperative for COCOBOD to ramp up strategies at preserving cocoa farm ecology to safe guard the industry.

Systematic mapping of global research on arthropods associated with cacao agroecosystem: trends and gaps

Article

Full-text available

Sep 2024
ARTHROPOD-PLANT INTE

Arthropods are crucial for sustaining global cacao cultivation, contributing to diverse ecological functions within the cacao agroecosystem. Despite their importance, there’s a lack of comprehensive documentation on factors influencing arthropod presence, ecosystem services, impact, management, and conservation across cacao cultivation systems. To bridge this gap, our study aimed to consolidate existing knowledge by systematically mapping global scientific articles on arthropods associated with cacao cultivation. Using advanced text mining and structural topic modeling, we identified eight thematic categories in 552 articles, with 69.6% published between 2000 and 2023. Geographically, studies were concentrated in America (38.2%), Africa (34.6%), and Asia (20.8%). Publications showed a surge across most topics, providing updated insights into their distribution. Research in America focused on beetles, parasitoid hymenopterans, ants, pollinating dipterans, and arachnids. Conversely, substantial publications addressed pest arthropods, including hemipterans in Africa, the Cocoa Pod Borer in Asia, and other pests in America and Africa. Through our systematic analysis, we uncovered key topics shedding light on arthropod biology and ecological interactions, highlighting the importance of agroforestry systems for conserving diversity and promoting ecosystem services like pollination and biological control. The study outlines research trends and gaps within each topic, serving as a valuable resource for professionals and policymakers, facilitating further investigations into arthropods in the cacao agroecosystem.

Nitrogen, phosphorus and potassium nutrition effects on flowering and reproduction in an F1 segregating population of the Theobroma cacao L. CCN-51 cultivar

Article

Sep 2024
SCI HORTIC-AMSTERDAM

Cacao (Theobroma cacao L.) is a globally significant perennial crop primarily cultivated in tropical regions, where it provides employment to millions of people. Crop productivity is chronically low, and it is imperative to have good information on the cacao plant nutrient demands to maximize yield. The objective of this study was to assess the effects of nitrogen (N), phosphorus (P), and potassium (K) availability on flowering time, flowering intensity, pollen viability, and fruiting of cacao (Theobroma cacao L.). An F1 segregating population of the CCN-51 cultivar was studied, as this is a well-defined commercially important hybrid cultivar, and because the vast majority of cacao is grown from hybrid seeds. Using a lysimeter setup, young seedlings were grown from the age of 9 months with different levels of N, P, and K loads. Low N, P, and K doses significantly delayed flowering time and reduced the number of flower cushions and flowering intensity. At the highest N dose, flowering intensity was lower than at intermediate N doses. Pollen viability and germination, on the other hand, were not affected by changes in N, P, and K input concentrations. Flowering intensity was the same on the trunk and canopy of a given tree, regardless of the treatment. Nitrogen availability played an important role in natural fruit set in this first year of fruiting, with increasing N resulting in increasing natural fruit set. This study shows the importance of N, P and K optimization for cacao reproduction. Optimizing nutrient availability could have a great impact on its productivity and yield.

Floral biology and flower visitors of cocoa (Theobroma cacao L.) in the upper Magdalena Valley, Colombia

Article

Apr 2024
FLORA

Employing agricultural extension delivery services for improving cocoa bean quality

Article

Full-text available

Mar 2024

Agricultural extension services are supposed to provide farmers with the know-how and abilities they need to boost productivity, and create premium cocoa beans. In this study, a sample of 384 farmers participated and data collected was analysed using descriptive statistics. The findings reveal that demonstration farms (72.92%) are very effective for disseminating innovations to cocoa farmers. Farmers believe that agricultural extension services play a favourable role in improving the quality of cocoa (Mean = 3.93). Household size, years of farming, off-farm activities, access to credit and access to technical assistance statistically influence cocoa farmers’ choice of extension delivery methods (p < 0.05). Cocoa farmers perceive that agricultural extension services exert positive influence on various aspects of cocoa production (Mean = 3.96). The farmers ranked insufficient knowledge and awareness about the benefits of adopting agricultural extension methods for cocoa bean quality enhancement as their most critical constraint (Mean rank: 1.26). Based on the findings, there should be a concerted effort to promote the establishment of demonstration farms within cocoa-growing regions to serve as practical learning hubs where farmers can observe and learn about new techniques for improving their cocoa bean quality.

Pangenomic exploration of Theobroma cacao : New Insights into Gene Content Diversity and Selection During Domestication

Preprint

Full-text available

Nov 2023

The Cacao tree ( Theobroma cacao L.) is a major cash crop and an important source of income for millions of farmers across Africa, Asia and Latin America. However, cacao farmers and producing countries are facing multiple challenges including pest and disease management, sustainable production under threat of climate changes and diversification of cocoa flavor profiles. Addressing these challenging requires a deeper understanding of the existing genetic diversity of the species. Yet, very little is known about the intraspecific gene content variation. In this study, we used the genome of 216 accessions of T. cacao (including 185 newly re-sequenced) covering a broad genetic diversity of the species to construct the first pan-genome of the cacao tree. As a result, we predicted a total of 30,489 pan-genes, enriching the reference Criollo genome with 1,407 new genes. Our analysis revealed that only a small fraction of these genes (9.2%) is dispensable, being absent in some individuals. However, these genes could represent a valuable resource for breeding efforts aimed at improving disease resistance in the species. We used this new pangenome resource to gain insights into how diversification and domestication processes have influenced genomic variability within the species. Notably, we observed a significant loss of genes within the domesticated Criollo genetic group. Furthermore, we found evidences suggesting that domestication processes have had an impact on the vigor and disease tolerance of Criollo accessions. In summary, our research has contributed to a better understanding of the cacao tree’s genome diversity. These findings offer new avenues for biological discovery and breeding, ultimately addressing the challenges faced by cacao farmers and producing countries.

Tree diversity in a tropical agricultural-forest mosaic landscape in Honduras

Article

Full-text available

Nov 2022

Biodiversity decline in the tropics requires the implementation of comprehensive landscape management where agricultural systems are necessarily an integral element of biodiversity conservation. This study evaluates the potential for taxonomic biodiversity conservation within an intensive livestock-agricultural-forest mosaic landscape in Catacamas, Honduras. Tree sampling was performed in 448 plots set up within different forest and agricultural land uses: secondary forests, agroforestry coffee plantations, agriculture, pastures, live fences and riparian forest. All trees with a minimum diameter at breast height of 10 cm were identified and measured. We characterized their tree structure and diversity, and compared tree diversity between the different uses. The results indicate a high degree of tree species diversity: 375 species identified, belonging to 74 families among the 15,096 trees inventoried across 84.2 hectares, including many rare species (40% of the species registered three individuals or fewer). Biodiversity indices for agroforestry coffee were found equivalent to those for natural secondary forests in the Catacamas landscape. Combining biodiversity conservation and agricultural production is possible in human-pressured tropical landscapes through tree cover maintenance. Enrichment practices combining local producers and technical knowledge may improve tree diversity in agricultural landscapes by prioritizing a mix of forest and introduced tree species (rare and with multiple uses).

Assessment of a Cocoa-Based Agroforestry System in the Southwest of Colombia

Article

Full-text available

Aug 2022

Cocoa-based agroforests play an important role in farmer livelihood and the global environment; however, despite these facts, their low yields and tree aging put at risk their fate. This project investigated the carbon storage potential, productivity, and economics of different agroforestry arrangements of cocoa (Theobroma cacao) with Melina (Gmelina arborea) trees, in the southwest of Colombia. We established the experiment under a Randomized Complete Blocks design with seven treatments and three repetitions. Different allometric models were tested. Allometric models were made for G. arborea trees with dbh, ranging between 30.24 and 50.11 cm. The total carbon accumulation fluctuated between 49.2 (Treatment 4) and 88.5 t ha−1 (Treatment 2), soil organic matter (SOM) ranged between 9 and 17%, bulk density decreased from 0.83 to 0.77 g cm−3. Cocoa yield ranged between 311 kg ha−1 year−1 (Treatment 7, traditional farm) and 922 kg ha−1 year−1 (Treatment 6). Treatment 6 showed the best performance with a net present value (NPV) of COP 1,446,467 (US $337.6), an internal rate of return (IRR) of 42%, and a cost-benefit ratio (B/C) of 1.67%. The benefits of AFS were also evidenced in some of the physical and chemical soil properties. Despite local marginality, these cocoa agroforest arrangements are a viable alternative to improve the traditional (local) cocoa systems because cacao agroforest arrangements increased cacao yield and carbon storage becoming a suitable alternative to improve traditional systems.

Feasibility of Mechanical Pollination in Tree Fruit and Nut Crops: A Review

Article

Full-text available

May 2022

Pollination is essential for the production of most fruit and nut crops, yet it is often a limiting factor for both yield and product quality. Mechanical pollination (MP) systems offer the potential to increase productivity of a broad range of horticultural fruit and nut crops, and to manage the risk of reliance on current insect pollination services. To date, commercial MP systems have been developed for only a few crops (e.g., kiwifruit and date palm), suggesting that innovation in the use of MP systems has been stymied. Here, we review published and ‘grey’ literature to investigate the feasibility of MP systems of economically important tree fruit and nut crops. This review found that, whilst MP systems are a commercial reality for a wider range of fruit crops (e.g., sweet cherry) than nut crops (e.g., almond), promising results have been achieved at the experimental scale. Further we identified that the key barriers for progressing MP systems more widely include knowledge gaps in pollination biology, particularly of emerging fruit and nut species that are grown outside their native distributions, and access to proprietorial knowledge gained by commercial operators. What continues to remain unclear is detailed knowledge of the commercial development of MP systems and therefore, the opportunities to apply this knowledge to other tree crops where effective pollination limits yield and quality.

Reproductive ecology of white cacao (Theobroma bicolor Humb. & Bonpl.) in Ecuador, western Amazonia: floral visitors and the impact of fungus and mistletoe on fruit production

Article

Sep 2021
Rev Bras Botânica

Theobroma bicolor is widely distributed in the Neotropics with great potential for economic use. However, very little is available in literature about its pollinators and reproductive ecology in comparison to what is available about its economically more important relative T. cacao. We studied aspects of the floral biology, reproductive phenology and biotic restrictions to the reproduction of the species. We measured, observed and monitored flowers and described their morphology, breeding system, receptivity times of the stigma and peaks of flower and fruit production. During 20 consecutive days, we collected floral visitors of 135 ± 45 flowers per day. We also calculated the damage in fruit production generated by the mistletoe (Oryctanthus cf. alveolatus) and the fungus (Moniliophthora roreri). We found that flower stigma was more receptive between 6:00-10:00 and flowers last up to three days on the tree, which is less time than what has been reported elsewhere. We collected 211 insects from 68 different morphotypes, but five of these represented 49.8% of the total; specimens of Ceratopogonidae, Chironimidae and Sciaridae were the most abundant and could be pollinators of the species. The flowering of T. bicolor showed a positive correlation (r > 0.75) with the months with higher temperature and solar radiation. We recorded an average per tree of 7 ± 5 fruits. We found a drastic loss of 84% of fruits in the plants infested by the mistletoe O. cf. alveolatus and of 29% when infested by the fungus M. roreri. The results of this study serve as a basis to generate local management practices.

Sexual Reproduction of cacao

Technical Report

Full-text available

Apr 2010

The Central American Cacao Project (PCC) at CATIE (Tropical Agricultural Research and Higher Education Center) aims to increase the productivity, diversity and financial and environmental value of the cacao plantations of at least 6,000 Central American families. Working closely with cacao farming families, the Project creates alliances with other partners in the region in order to enhance the social interactions, competitiveness and business capacity of the producers’ organizations and improve the living conditions of their members. The Project promotes efforts to increase the knowledge and skills of farming families and students at agricultural schools, technical colleges and agronomy faculties, for the sustainable production of cacao. The Project also offers equal opportunities as well as economic, social and cultural responsibilities for men and women in all its spheres of action.

Carbon stocks and cocoa yields in agroforestry systems of Central America

Article

Full-text available

Jan 2013

The cocoa tree (Theobroma cacao L.) is cultivated typically in agroforestry systems in close association with a rich list of tree species and other useful plants on the same plot. Cocoa based agroforestry systems are credited for stocking significant amounts of carbon and hence have the potential to mitigate climate change. Since cocoa yields decrease non-linearly with increasing shade, a need is to design optimal cocoa agroforestry systems with high yields and high carbon stocks. We estimated the carbon stocked in a network of 229 permanent sample plots in cacao-based agroforestry systems and natural forests in five Central American countries. Carbon stocks were fractioned by both system compartments (aboveground, roots, soil, litter, dead wood – fine and coarse, and total) and tree use/form (cocoa, timber, fruit, bananas, shade and ornamentals, and palms). Cocoa plantations were assigned to a five-class typology and tested for independence with growing region using contingency analysis. Most Central American cocoa plantations had mixed or productive shade canopies. Only 4% of cocoa plantations were full sun or rustic (cocoa under thinned natural forest). Cocoa tree density was low (548 ± 192 trees ha−1). Total carbon (soil + biomass + dead biomass) was 117 ± 47 Mg ha−1, with 51 Mg ha−1 in the soil and 49 Mg ha−1 (42% of total carbon) in aboveground biomass (cocoa and canopy trees). Cocoa trees accumulated 9 Mg C ha−1 (18% of carbon in aboveground biomass). Timber and fruit trees stored 65% of aboveground carbon. The annual rate of accumulation of carbon in aboveground biomass ranged between 1.3 and 2.6 Mg C ha−1 y−1. Trade-offs between carbon levels and yields were explored qualitatively using functional relationships documented in the scientific and technical literature, and expert knowledge. We argue that it is possible to design cocoa-based AFS with good yields (cocoa and shade canopy) and high carbon stock levels. The botanical composition of the shade canopy provides a large set of morphological and functional traits that can be used to optimize shade canopy design. Our results offer Central American cocoa producers a rigorous estimate of carbon stocks in their cocoa plantations. This knowledge may help them to certify and sell their cocoa, timber, fruits and other goods to niche markets with good prices. Our results will also assist governments and the private sector in (i) designing better legal, institutional and policy frameworks, local and national, promoting an agriculture with trees and (ii) contributing to the development of the national monitoring, reporting and verification systems required by the international community to access funding and payment for ecosystem services.

OVERCOMING THE MAIN LIMITING FACTORS OF CACAO PRODUCTION IN CENTRAL AMERICA THROUGH THE USE OF IMPROVED CLONES DEVELOPED AT CATIE

Conference Paper

Full-text available

Sep 2009

REFERENCE: Phillips-Mora, W.; Castillo, J.; Arciniegas, A.; Mata, A.; Sánchez, A.; Leandro, M.; Astorga, C.; Motamayor, J.; Guyton, B.; Seguine, E.; Schnell, R. 2009. Overcoming the main limiting factors of cacao production in Central America through the use of improved clones developed at CATIE. ABSTRACT Cacao cultivation has been an important component of Central American culture and commerce since pre-Columbian times. However, during the last decades of the 20 th century, cacao production declined considerably in this region due to the dramatic impact of pod diseases, the low yield-potential of the plantations, and the frequent periods of low prices. An expansion of the activity is currently underway encouraged by the improvement of international and local prices and the increased interest in the markets for Trinitario cacaos, which are prevalent in Central America. Success of these renovated efforts will depend on the ability to overcome the main biotic factors limiting cacao production: the incidence of frosty pod rot (FPR, Moniliophthora roreri) and to a lesser extent, black pod disease (BPD, Phytophthora palmivora), and the necessity to renovate/rehabilitate the unproductive and susceptible plantations using improved varieties. Clones resistant to FPR and/or BPD were identified in the International Cacao Genebank (IC3) by using artificial inoculation techniques developed at CATIE. They were incorporated in a breeding strategy initiated at CATIE in the late 1990's to generate superior clones and hybrid families possessing disease resistance, high-yield and good quality. This effort has been supported by the World Cocoa Foundation, USDA-ARS, and CFC/Bioversity. The first outstanding clones were recently released for farmer observation and eventual use in six Central American countries through a regional cacao project (PCC), which is executed by CATIE and supported by NORAD (Norway) and farmer organizations. A comprehensive characterization/evaluation of the released clones was previously performed by using different agronomic, morphological, and phytopathological parameters. Self-and cross-compatibility were also determined. The results were complemented with a quality study supported by Guittard Chocolate Co. The establishment of 30 hectares of clonal gardens and 6 hectares of experimental field trials are part of the regional strategy in progress.

Abundance and diversity of flower visitors on wild and cultivated cacao (Theobroma cacao L.) in Bolivia

Article

Full-text available

Feb 2018
AGROFOREST SYST

Despite the economic importance of Theobroma cacao, surprisingly little is known about its pollination ecology. Ceratopogonid midges are considered to be the main pollinators, but the limited available evidence on the sexual reproduction is based almost exclusively on cultivated cacao and knowledge is nonexistent for wild populations. We documented flower visitors in wild and cultivated plants by applying glue on 2237 flowers of wild and cultivated cacao trees in Bolivia to trap floral visitors. We caught 631 insects belonging to seven orders, corresponding to a mean capture rate of 0.3 insects per flower. The most abundant and diverse insect order on both cacao types was Hymenoptera, represented mainly by small parasitoids. Hymenoptera were more abundant on wild cacao, whereas species richness was higher on cultivated cacao. The abundance and species richness of Diptera were not significantly different between wild and cultivated cacao. However, species composition and proportion of Diptera species differed between both wild and cultivated cacao. Ceratopogonidae were only represented by 13 individuals belonging to seven species. Cacao pollen was carried by only a single specimen of Encyrtidae. We were thus unable to identify actual pollinators. We found significant differences among the visitor assemblages between wild and cultivated cacao, which suggest that midges alone were probably too rare to act as main or even sole pollinators of cacao in our study region. Potential additional pollinators would be small Diptera (e.g., Chloropidae and Phoridae) and Hymenoptera (e.g., Eulophidae and Platygastridae).

Composición florística y estructura de cacaotales y parches de bosque en Waslala, Nicaragua

Article

Full-text available

Jan 2013

We studied the botanical and structural composition of the woody vegetation present in 36 cocoa-AFS and four forest patches located on the Nicaraguan Atlantic slope. We set up a 1000 square meter plot (20x50 m) where we identified, counted and measured all trees with dbh ≥ 10 cm and we used a semi-structured interview process with 36 producers to investigate cacao agronomic management and the use and management of shade trees. Cacao plant density was 660 trees ha-1; the cocoa-AFS had a total of 521 individuals (145 trees ha-1) in 35 families, 57 genera and 70 species on 3.6 ha. Musaceae were the most abundant species (182 stems ha-1) followed by Cordia alliodora (22 trees ha-1), Bactris gasipaes (20 individuals ha-1) and Ryania speciosa (17 plants ha-1). In the forest patches we counted 869 trees (2173 trees ha-1) in 47 families, 80 genera and 90 species. The most abundant and common species in the forest plots were Ryania speciosa (173 plants ha-1), Piper aduncum (143 trees ha-1) and Parkinsonia aculeata (83 trees ha-1). The diversity of woody species associated with cacao lower than the tree diversity recorded in forest patches, although it is within the ranges measured in other Central American cocoa orchards. The horizontal structure of the tree vegetation in cocoa-AFS was markedly different from that of forest patches. Up to 25% of the tree species inventoried in forest patches were recorded for the cocoa-AFS. We suggest promoting the diversification of the cacao orchards and other areas of the farm with fruit trees and valuable timber trees and we recommend providing technical assistance to producers about the selection of species for shade, management of natural regeneration and the design and management of shade in cacao orchards.

Vulnerability to climate change of cocoa in West Africa: Patterns, opportunities and limits to adaptation

Article

Full-text available

Mar 2016
SCI TOTAL ENVIRON

The West African cocoa belt, reaching from Sierra Leone to southern Cameroon, is the origin of about 70% of the world's cocoa (Theobroma cacao), which in turn is the basis of the livelihoods of about two million farmers. We analyze cocoa's vulnerability to climate change in the West African cocoa belt, based on climate projections for the 2050s of 19 Global Circulation Models under the Intergovernmental Panel on Climate Change intermediate emissions scenario RCP 6.0. We use a combination of a statistical model of climatic suitability (Maxent) and the analysis of individual, potentially limiting climate variables. We find that: 1) contrary to expectation, maximum dry season temperatures are projected to become as or more limiting for cocoa as dry season water availability; 2) to reduce the vulnerability of cocoa to excessive dry season temperatures, the systematic use of adaptation strategies like shade trees in cocoa farms will be necessary, in reversal of the current trend of shade reduction; 3) there is a strong differentiation of climate vulnerability within the cocoa belt, with the most vulnerable areas near the forest-savanna transition in Nigeria and eastern Côte d'Ivoire, and the least vulnerable areas in the southern parts of Cameroon, Ghana, Côte d'Ivoire and Liberia; 4) this spatial differentiation of climate vulnerability may lead to future shifts in cocoa production within the region, with the opportunity of partially compensating losses and gains, but also the risk of local production expansion leading to new deforestation. We conclude that adaptation strategies for cocoa in West Africa need to focus at several levels, from the consideration of tolerance to high temperatures in cocoa breeding programs, the promotion of shade trees in cocoa farms, to policies incentivizing the intensification of cocoa production on existing farms where future climate conditions permit and the establishment of new farms in already deforested areas.

Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms

Article

Full-text available

Jan 2016
SCIENCE

More-diverse pollinators improve crop yields It is known that increased pollinator diversity can improve the yield of agricultural crops. However, how best to both produce food and maintain diversity is still debated. Garibaldi et al. show that on small farms, which provide food for the most vulnerable populations globally, pollinator diversity can significantly increase productivity. Thus, the management of crops and surrounding areas for ecological health is likely to benefit both wild pollinator populations and farmers. Science , this issue p. 388

Postharvest practices and farmers’ perception of cocoa bean quality in Cameroon

Article

Full-text available

Dec 2015

After the closure of Cameroon’s National Produce Marketing Board in 1990, rigorous measures no longer existed to control production of quality cocoa. This study assesses farmers’ knowledge of postharvest practices that could influence cocoa bean quality (CBQ), their perception of quality cocoa and the factors that hinder good farming and postharvest practices (GFPHP). We also make suggestions on how quality control can be incorporated in the production chain to improve on CBQ produced. In a cross-sectional, purposive study in Fako Division, South West Region of Cameroon, 100 farmers were enrolled from 10 villages (10 from each village) which make up the major production area in Agro-ecological Zone IV of Cameroon. Farmers were administered a semi-structured questionnaire in the language they best understood. Cocoa farming in this area is a tradition and our results show that 97 % of farmers are males and acquired farming practices mainly through their family member (43 %) and/or friends (34 %). Farms are self-owned, 76 and 85 %, respectively, are less than 5Ha and have been cultivated for more than 20 years. Only 10 % of farmers could perceive quality cocoa using physical characterization. Although more than 95 % of farmers knew GFPHP, only 48 % undertake these practices. Farmers’ focus was on bean weight and not on CBQ and 64 % of farmers think quality has little impact on the price. Most farmers (71 %) sell to “buyam-sellams” who care little about quality. The proportion of respondents who acquired knowledge through formal learning was significantly higher than those who did so from informal learning with regards to both good cocoa production practice (p = 0.036) and appreciation of quality attributes (p = 0.043). Subsidizing inputs, access to credits, creating cooperatives, regulating price of cocoa and training on postharvest management in decreasing order could enhance practices that will ensure quality cocoa production. GFPHP is important in the production of quality cocoa. Left alone, farmers will not pay attention to these quality attributes especially as premium quality is not rewarded. Organizing farmers into cooperatives will reduce the link between farmers and companies exporting cocoa and alleviate most bottlenecks in the sector.

Pollinator Management And Insecticide Usage Within Cocoa Agroecosystem In Ghana

Article

Full-text available

Jan 2013

Ghana being a leading cocoa producer, depends heavily on pesticides although the crop is strictly entomophilous, primarily pollinated by ceratopogonid midges. This study in Ghana, investigated impact of confidor 200SL (Imidacloprid) and aqueous neem seed extract (ANSE) insecticides on abundance of pollinators and fruit-set in cocoa Three pollinator sampling methods (motorized aspirator, pan and McPhail traps) were used. Results show significantly more abundant midges on ANSE treated farms compared to confidor treated farms, 2 (t = 4.34; df = 69; P < 0.001) and 60 – 120 (t = 1.85; df = 39; P < 0.041) days after spraying insecticides (DASI). Midge population recovered within 30 DASI under both insecticide treatments culminating in comparable abundance over this period. Fruit-sets within 30 DASI were however significantly higher indicating that fruit-set is affected though midge population recovered. Although both insecticides were deleterious to the midges, ANSE was lesser and therefore preferred to confidor. This result show both insecticides did not discriminate against beneficial insects, hence it will be important to consider a more comprehensive approach to the study of managing insect fauna complex within cocoa agroecosystem.

Dynamics of insect pollinators as influenced by Cocoa Production systems in Ghana

Article

Full-text available

Jul 2011

Cocoa is strictly entomophilous but studies on the influence of the ecosystem on insect pollinators in cocoa production systems are limited. The abundance of cocoa pollinators and pod-set of cocoa as influenced by a gradient of farm distances from natural forest and proportion of plantain/banana clusters in or adjacent to cocoa farms were therefore investigated. Cocoa pollinators trapped were predominantly ceratopogonid midges hence, analyses were based on their population. Variation in farm distance to forest did neither influence ceratopogonid midge abundance nor cocoa pod-set. However, we found a positive relationship between pollinator abundance and pod set and the proportion of plantain/banana intercropped with cocoa. The results suggest appropriate cocoa intercrop can enhance cocoa pollination, and the current farming system in Ghana can conveniently accommodate such interventions without significant changes in farm practices.

The occurrence of insects and moulds in stored cocoa beans at South Sulawesi

Article

Full-text available

Jan 1999

Surveys on postharvest handling and technology processing of cocoa beans at farmer, trader and exporter levels in South Sulawesi were conducted together with investigations on moisture content, pest infestation (insect and mould) and quality characteristics in terms of reducing sugar, free amino acid and free fatty acid content. Surveys were conducted during dry (July 1997) and wet seasons (February 1998) in three regencies (Pinrang, Polewali-Mamasa and Luwu) and Ujung Pandang, South Sulawesi province. Interviews were carried out during surveys in the dry season. Number of respondents from farmers, trailers and exporters was 38, 15 and 5, respectively. In each season, number of samples taken from farmers, traders and exporters was 9, 21 and 15, respectively. In general, farmers, traders and exporters did not carry out postharvest handling and technology processing properly. MoistureÂ content of cocoa beans collected from farmers, traders and exporters were higher than the tolerable limit recommended by SNI (7.5%). Moisture content of cocoa beans collected during the wet season was higher than in the dry season. Insects were found on cocoa beans collected from traders and exporters. Species composition and the presence of each insect species were varied among the two seasons, but the predominant species was Tribolium castaneum. At trader level the percentage of insect-damaged beans during the wet season was higher than that during the dry season, while at exporter level it was lower. During the two seasons the percentage of mouldy beans at farmer level was lower than the tolerable limit recommended by SNI (4%), while those from some samples at trader and exporter levels were higher than 4%, but based on the direct plating method, all of the samples at trader and exporter levels were mouldy. Species composition and the percentage of beans infected by each mould species at farmer, trader and exporter levels during the two seasons were varied. The percentage of mouldy beans increased at trader and exporter levels. The predominant moulds were Aspergillus flaws, Eurotium amstelodami, E. chevalieri and Penicillium citrinum. The predominant mould at farmer level during wet season was Saccharomyces cerevisiae (yeast). Reducing sugar and free amino acid content of cocoa beans collected during the dry season was higher than those collected during the wet season, either at farmer, trader or exporter levels. Free fatty acid content of cocoa beans tends to be higher during the wet season than the dry season at the three levels. Keywords: Stored products pests/Postharvest handling/Technology processing/Moisture content/In- sect/Mould/Reducing sugars/Free amino acids/Free fatty acids/Cocoa/South Sulawesi.

Insect assemblage and the pollination system in cocoa ecosystems

Article

Full-text available

Mar 2013

Objective: An insect survey was carried out in ten farm plots to determine whether there are other tropical pollinators of cocoa which are either unidentified or undescribed, and hence review the pollination system of the crop. Methodology and results: Ten homogenous farmer managed farm plots were selected. For three consecutive years, a study was carried out to determine the insect species richness and relative abundance in the farm plots during flowering seasons (April to October). It was also to determine which of the insects were pollinators or contributed to the process of pollination of cocoa. Trees used were selected based on availability of flowers. About 2,721 insects belonging to 36 species and 7 orders were recorded. Insect species of the orders viz: Hymenoptera, Diptera, Orthoptera, and Coleoptera were common to all the ten farm plots. These were found on cocoa trees, and on the ground among the cocoa leaf litter. The rest were predominantly aerial or flying insects. The results of focal patch observation indicated that more than half of insect species resident in the cocoa ecosystem did not visit the cocoa flowers. Those which visited did not carry any pollen. Only the ceratopogonid midges (Diptera) showed higher pollinator importance. They were therefore classified as effective pollinators, and hence could be beneficial to the productivity of cocoa. None of the crawling insects ever carried pollen to the stigma. The study showed that the cocoa ecosystem could support diverse insect communities; however, the evolution of the floral structure of cocoa restricts access to all but few pollinators. Cocoa therefore has a specialized pollination system. Conclusion and application: The study showed that though the cocoa ecosystem could support diverse insect communities the cocoa tree itself has a specialized pollination system. The results therefore suggest that cocoa farmers should be encouraged to incorporate pollinator-friendly practices for sustainable cocoa production.

Biodiversity is affected by changes in management intensity of cocoa-based agroforests

Article

Full-text available

Dec 2014

In the humid tropics, the rapid rate of deforestation has resulted in a race to protect remaining forest patches that are increasingly isolated within a rapidly expanding agricultural matrix. In these landscapes, a significant area consists of complex agro-forestry systems with high structural and functional plant diversity, providing critical resources for biodiversity conservation, such as food and habitat. Although not a substitute for natural forests, these anthropogenic habitats are gaining increasing conservation value as deforestation progresses. Shaded tree crops, such as cocoa, provide habitats for numerous forest dependent species of high conservation value and play a largely undocumented role in providing other ecological services. Following previous work on the botanical composition and structural complexity of cocoa agroforests in Talamanca (Costa Rica), we assessed if differences in the vegetation composition and structure of 36 cocoa agroforests could affect the wild diversity of small mammals, amphibians, reptiles, soil and litter macro-invertebrates and epiphytes found on cocoa trees and associated plants. Results show that Alpha-diversity is not affected by changes in vegetation structure and composition, except for amphibians and epiphytes found on cocoa trees. However, five taxa among eight showed distinct species composition patterns when compared among cocoa-based agroforestry clusters and with forest control. We showed that beta-diversity assessment enhances our understanding of the effect of management intensification on species composition and on habitat quality. The proper design of the shade component in these AFS will certainly play a key role in segregating wild species hosted in these systems and will open a new field of research for the intensification of both cocoa and associated productions in these highly diverse systems.

Diversification practices reduce organic to conventional yield gap

Article

Full-text available

Jan 2015
Proc Biol Sci

Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. How organic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (±3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9 ± 4% and 8 ± 5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions.

Structure and Stability of Cocoa Flowers and Their Response to Pollination

Article

Full-text available

Mar 2014
JB

This study investigated the position of staminodes around the style of cocoa flowers and the stability of cocoa flowers relative to pollination and seasonality. Cocoa flowers were categorized into converging, ≤1.20 mm; parallel, 1.21-2.40 mm, and splay ≥2.41 mm, depending on the distance between the staminode and style. Some flowers were hand pollinated while others were not and were excluded from insect visitors. Proportions of flowers of converging (56.0%), parallel (37.5%), and splay (6.5%) remained similar along the vertical plane of cocoa trees. Although pollination rates of flowers with splay staminodes were the lowest, the overall pollination success of cocoa trees was not significantly affected because of the small proportion of splay flowers.The stability of the cocoa flowers depended on both the season and pollination. During the dry season, unpollinated flowers of cocoa trees showed a flower-stability ratio of 72% on the second day, while the flower-stability ratio was 94% in the wet season. Pollinated (senescent) flowers had a stability ratio of 95% after 5 days during the wet season, but all pollinated flowers dropped after 5 days in the dry season, indicating that seasonal factors, such as water stress, can have dramatic effects on cocoa yields.

Agronomic performance of 27 cocoa progenies and plant selection based on productivity, self-compatibility and disease resistance

Article

Full-text available

Aug 2013

The objective of the present work was to evaluate 27 progenies of cocoa crosses considering the agronomic traits and select F1 plants within superior crosses. The experiment was installed in March 2005, in the Experimental Station Joaquim Bahiana (ESJOB), in Itajuipe, Bahia. The area of the experiment is of approximately 3 ha, with a total of 3240 plants. Thirteen evaluations of vegetative brooms, five of cushion brooms and 15 of number of pods per plant were accomplished. Thirty pollinations were made for each selected plant to test for self-compatibility. The production, based on the number of pods per plant, and resistance to witcheś broom indicated CEPEC 94 x CCN 10, RB 39 x CCN 51 and CCN 10 x VB 1151 as superior progenies. All selections tested were self-compatible. The analyses of progenies and individual tree data, associated to visual field observations, allowed the selection of 17 plants which were included in a network of regional tests to determine the phenotypic stability.

OVERCOMING THE MAIN LIMITING FACTORS OF CACAO PRODUCTION IN CENTRAL AMERICA THROUGH THE USE OF IMPROVED CLONES DEVELOPED AT CATIE

Article

Full-text available

Cacao cultivation has been an important component of Central American culture and commerce since pre-Columbian times. However, during the last decades of the 20 th century, cacao production declined considerably in this region due to the dramatic impact of pod diseases, the low yield-potential of the plantations, and the frequent periods of low prices. An expansion of the activity is currently underway encouraged by the improvement of international and local prices and the increased interest in the markets for Trinitario cacaos, which are prevalent in Central America. Success of these renovated efforts will depend on the ability to overcome the main biotic factors limiting cacao production: the incidence of frosty pod rot (FPR, Moniliophthora roreri) and to a lesser extent, black pod disease (BPD, Phytophthora palmivora), and the necessity to renovate/rehabilitate the unproductive and susceptible plantations using improved varieties. Clones resistant to FPR and/or BPD were identified in the International Cacao Genebank (IC3) by using artificial inoculation techniques developed at CATIE. They were incorporated in a breeding strategy initiated at CATIE in the late 1990's to generate superior clones and hybrid families possessing disease resistance, high-yield and good quality. This effort has been supported by the World Cocoa Foundation, USDA-ARS, and CFC/Bioversity. The first outstanding clones were recently released for farmer observation and eventual use in six Central American countries through a regional cacao project (PCC), which is executed by CATIE and supported by NORAD (Norway) and farmer organizations. A comprehensive characterization/evaluation of the released clones was previously performed by using different agronomic, morphological, and phytopathological parameters. Self-and cross-compatibility were also determined. The results were complemented with a quality study supported by Guittard Chocolate Co. The establishment of 30 hectares of clonal gardens and 6 hectares of experimental field trials are part of the regional strategy in progress.

Cocoa shortfall: Pollination curbs climate risk to cocoa

Article

Full-text available

Jul 2014

Thomas C. Wanger

A meta-analysis of crop yield under climate change and adaptation

Article

Full-text available

Mar 2014
Nat. Clim. Change.

Feeding a growing global population in a changing climate presents a significant challenge to society. The projected yields of crops under a range of agricultural and climatic scenarios are needed to assess food security prospects. Previous meta-analyses have summarized climate change impacts and adaptive potential as a function of temperature, but have not examined uncertainty, the timing of impacts, or the quantitative effectiveness of adaptation. Here we develop a new data set of more than 1,700 published simulations to evaluate yield impacts of climate change and adaptation. Without adaptation, losses in aggregate production are expected for wheat, rice and maize in both temperate and tropical regions by 2 °C of local warming. Crop-level adaptations increase simulated yields by an average of 7–15%, with adaptations more effective for wheat and rice than maize. Yield losses are greater in magnitude for the second half of the century than for the first. Consensus on yield decreases in the second half of the century is stronger in tropical than temperate regions, yet even moderate warming may reduce temperate crop yields in many locations. Although less is known about interannual variability than mean yields, the available data indicate that increases in yield variability are likely.

The Role of Trees in Agroecology and Sustainable Agriculture in the Tropics

Article

Full-text available

May 2014

Leakey RRB

Shifting agriculture in the tropics has been replaced by sedentary smallholder farming on a few hectares of degraded land. To address low yields and low income both, the soil fertility, the agroecosystem functions, and the source of income can be restored by diversification with nitrogen-fixing trees and the cultivation of indigenous tree species that produce nutritious and marketable products. Biodiversity conservation studies indicate that mature cash crop systems, such as cacao and coffee with shade trees, provide wildlife habitat that supports natural predators, which, in turn, reduce the numbers of herbivores and pathogens. This review offers suggestions on how to examine these agroecological processes in more detail for the most effective rehabilitation of degraded land. Evidence from agroforestry indicates that in this way, productive and environmentally friendly farming systems that provide food and nutritional security, as well as poverty alleviation, can be achieved in harmony with wildlife. Expected final online publication date for the Annual Review of Phytopathology Volume 52 is August 04, 2014. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.

Interaction complexity matters: Disentangling services and disservices of ant communities driving yield in tropical agroecosystems

Article

Full-text available

Jan 2014
Proc Biol Sci

Owing to complex direct and indirect effects, impacts of higher trophic levels on plants is poorly understood. In tropical agroecosystems, ants interact with crop mutualists and antagonists, but little is known about how this integrates into the final ecosystem service, crop yield. We combined ant exclusion and introduction of invasive and native-dominant species in cacao agroecosystems to test whether (i) ant exclusion reduces yield, (ii) dominant species maximize certain intermediate ecosystem services (e.g. control of specific pests) rather than yield, which depends on several, cascading intermediate services and (iii) even, species-rich ant communities result in highest yields. Ants provided services, including reduced leaf herbivory and fruit pest damage and indirect pollination facilitation, but also disservices, such as increased mealybug density, phytopathogen dissemination and indirect pest damage enhancement. Yields were highest with unmanipulated, species-rich, even communities, whereas ant exclusion decreased yield by 27%. Introduction of an invasive-dominant ant decreased species density and evenness and resulted in 34% lower yields, whereas introduction of a non-invasive-dominant species resulted in similar species density and yields as in the unmanipulated control. Species traits and ant community structure affect services and disservices for agriculture in surprisingly complex ways, with species-rich and even communities promoting highest yield.

Gene flow and genetic diversity in cultivated and wild cacao (Theobroma cacao) in Bolivia

Article

Full-text available

Oct 2013
AM J BOT

Premise of the study: The role of pollen flow within and between cultivated and wild tropical crop species is little known. To study the pollen flow of cacao, we estimated the degree of self-pollination and pollen dispersal distances as well as gene flow between wild and cultivated cacao (Theobroma cacao L.). Methods: We studied pollen flow and genetic diversity of cultivated and wild cacao populations by genotyping 143 wild and 86 cultivated mature plants and 374 seedlings raised from 19 wild and 25 cultivated trees at nine microsatellite loci. Key results: A principal component analysis distinguished wild and cultivated cacao trees, supporting the notion that Bolivia harbors truly wild cacao populations. Cultivated cacao had a higher level of genetic diversity than wild cacao, presumably reflecting the varied origin of cultivated plants. Both cacao types had high outcrossing rates, but the paternity analysis revealed 7-14% self-pollination in wild and cultivated cacao. Despite the tiny size of the pollinators, pollen was transported distances up to 3 km; wild cacao showed longer distances (mean = 922 m) than cultivated cacao (826 m). Our data revealed that 16-20% of pollination events occurred between cultivated and wild populations. Conclusions: We found evidence of self-pollination in both wild and cultivated cacao. Pollination distances are larger than those typically reported in tropical understory tree species. The relatively high pollen exchange from cultivated to wild cacao compromises genetic identity of wild populations, calling for the protection of extensive natural forest tracts to protect wild cacao in Bolivia.

Cacao Yield in Different Planting Densities

Article

Full-text available

Nov 2009
BRAZ ARCH BIOL TECHN

The effect of six planting densities on cacao yield of a commercial hybrid mixture as well as the interaction of planting densities with the years were investigated. Crop data collected over a 14-year period (1977-1990) showed that it was possible to optimise the regional cacao yields by implementing high planting densities (2500 and 1736 trees ha-1). This was however only true for the first half of the crop period. In the second half, low planting density (1059 trees ha-1) attained the best yields. This change in the ranking of planting densities over the years confirmed the presence of density-year interaction. Alternatives to achieve high productivity in high planting density systems were presented and discussed.

Cacao Cultivation and the Conservation of Biological Diversity

Article

Full-text available

May 2000

Cacao (Theobroma cacao) is a crop of the humid lowland tropics produced largely by small-scale producers and often on farms with a canopy of shade trees. Where a diverse shaded canopy is used, cacao farms support higher levels of biological diversity than most other tropical crops. A host of viral and fungal diseases, loss of soil fertility, and numerous socioeconomic problems facing producers, often makes cacao production locally unsustainable. Continued clearing of new lands threatens biodiversity. Moreover, new frontiers for cacao expansion are rapidly disappearing. Such problems can be addressed by increasing the long-term productivity of existing cacao farms and restoring abandoned lands. Improved shade management offers guidance along this path. Institutions involved with cocoa should establish collaborations with groups concerned with development, environmental protection, and most importantly producers themselves to pursue a program of research, extension and policy initiatives focused on the ecologically and economically sustainable cacao production on farms with a diverse shade canopy.

Botanical composition and structure of cocoa orchards and forest patches in Waslala, Nicaragua

Article

Full-text available

Jan 2013

Floristic composition and structure of cacao orchards and forest patches in Waslala, nicaragua We studied the botanical and structural composition of the woody vegetation present in 36 cocoa-AFS and four forest patches located on the Nicaraguan Atlantic slope. We set up a 1000 square meter plot (20x50 m) where we identified, counted and measured all trees with dbh ≥ 10 cm and we used a semi-structured interview process with 36 producers to investigate cacao agronomic management and the use and management of shade trees. Cacao plant density was 660 trees ha -1 ; the cocoa-AFS had a total of 521 individuals (145 trees ha -1) in 35 families, 57 genera and 70 species on 3.6 ha. Musaceae were the most abundant species (182 stems ha -1) followed by Cordia alliodora (22 trees ha -1), Bactris gasipaes (20 individuals ha -1) and Ryania speciosa (17 plants ha -1). In the forest patches we counted 869 trees (2173 trees ha -1) in 47 families, 80 genera and 90 species. The most abundant and common species in the forest plots were Ryania speciosa (173 plants ha -1), Piper aduncum (143 trees ha -1) and Parkinsonia aculeata (83 trees ha -1). The diversity of woody species associated with cacao lower than the tree diversity recorded in forest patches, although it is within the ranges measured in other Central American cocoa orchards. The horizontal structure of the tree vegetation in cocoa-AFS was markedly different from that of forest patches. Up to 25% of the tree species inventoried in forest patches were recorded for the cocoa-AFS. We suggest promoting the diversification of the cacao orchards and other areas of the farm with fruit trees and valuable timber trees and we recommend providing technical assistance to producers about the selection of species for shade, management of natural regeneration and the design and management of shade in cacao orchards.

Pollinators, pollination and cocoa production potential in agroforestry systems of Bocas del Toro, Panama

Article

Full-text available

Jan 2013

We analyzed the relationship of pollinating insects Ceratopogonidae (Atrichopogon, Dasyhelea, Forcipomyia) with shade canopy and land cover characteristics of cocoa agroforestry systems (AFS) for cocoa and cocoa production potential through the action of flowers pollinated naturally by pollinators. Pollinators were found in 60% of cocoa-AFS evaluated, with populations of 1800-19500 individuals ha-1. Insects in the genus Forcipomyia were the most important because of their greater abundance and positive relationship with the number of flowers pollinated/fertilized. Statistically significant and positive relationships were found between the abundance of pollinators with the density of cacao trees and the leaf litter cover and remains of decomposing fruit on the ground. The relationship was negative with the abundance of timber, musaceous, fruit and palm trees, and with the presence of stones, grass and bare soil. The negative relationship with canopy plants appears to be more influenced by excessive shade than by the abundance of plants per se. In cocoa-AFS with demonstrated presence pollinators, the percentage of flowers pollinated/fertilized was twice that of systems where they were not found (4% and 2% respectively). This confirms the importance of pollinators. Nevertheless, with only 2-4% of the flowers pollinated/fertilized thanks to pollinators, apparently cocoa production potential will not be good enough. The agroforestry management of the cocoa-AFS of Bocas del Toro must be improved to increase flowering and populations of insect pollinators.

Carbon stocks and cocoa yields in agroforestry systems of Central America

Article

Full-text available

Apr 2013
AGR ECOSYST ENVIRON

Dynamics of cocoa pollination: Tools and applications for surveying and monitoring cocoa pollinators

Article

Full-text available

Jun 2009
Int J Trop Insect Sci

Pollinators are important natural agents for fruit and seed formation in most tree crops and the use of appropriate sampling methods is fundamental in studying their population. A study to develop surveying and monitoring protocols for cocoa pollinators was undertaken in Ghana. Yellow, white and blue UV-bright painted pan traps (UVPPT), McPhail traps and motorized aspirators were used to sample pollinators of cocoa for 13 successive months, after 6 days assessment of the effectiveness of the traps and diurnal active period of the pollinators. The peak pollinating period of cocoa by ceratopogonid midges was between 07.00 and 12.00 h, as previously reported. All three methods were effective in sampling ceratopogonid midges with the UVPPT being the most efficient in terms of sampling effort. The number of ceratopogonid midges caught by the yellow-UVPPT was significantly higher than that by blue- and white-UVPPT. The diversity of midges caught could not be determined due to taxonomic difficulties, and thus all the three colours of UVPPT should be used until efficiency in terms of diversity is determined. It is reported here that the meliponine bee Liotrigona parvula Darchen visits cocoa flowers and thus their effectiveness in cocoa pollination should be investigated.

FLORAL NECTARIES AND TRICHOMES IN RELATION TO POLLINATION IN SOME SPECIES OF THEOBROMA AND HERRANIA (STERCULIACEAE)

Article

Apr 1984

Floral surfaces of two Theobroma spp. and one species of the allied genus Herrania (Sterculiaceae) were examined using scanning electron microscopy for reward system information of the pollinator-adaptation syndrome. These flowers are structurally complex and have sheltered reproductive parts indicating an elaborate insect-mediated pollination mechanism. Analysis of anther dehiscence, anthesis and pollen tube growth suggests a crepuscular pollination strategy. Suspected pollinators have been observed on floral parts of theobromas possessing stomate type nectaries and various shaped trichomes (blade of petal ligule and adaxial surface of petal hood). H. purpurea has elongate ligules devoid of stomates. Glandular clublike structures are found on the ovaries of all three spp. In numerous spp. of theobromas, except T. cacao, and two species of Herrania, a conspicuous ring of multicellular trichomes occurs at the adaxial base of the sepals. A possible function for the ring may be fragrance production because of its greatly reduced condition in the faintly scented T. cacao and the prevalence of pronounced fragrances in these other species.

Cacao cultivation and the conservation of biologicat diversity

Article

Jan 2000

Diel activity, frequency and visit duration of pollinators in focal plants: In situ automatic camera monitoring and data processing

Article

Feb 2017
Methods Ecol. Evol.

Ronny Steen

Data collection on interactions between organisms and their environment has traditionally been conducted by on‐site human observations, a time‐consuming enterprise that could explain the shortage of around‐the‐clock observations of free‐ranging wild animals. In this paper, I outline a time‐efficient procedure to collect data on flower‐visiting animals. The objectives were, first, to model diel activity rhythms by using cosine‐based mixed‐effects regression models (cosinor method) on data from an established automatic video monitoring system and, secondly, to test the use of a cheap off‐the‐shelf digital camera modified for automated monitoring of flower visitors. Two different model systems were studied: foraging bumblebees visiting focal white clovers, monitored around‐the‐clock (193 h) to model diel activity; and honeybees visiting thistles, monitored over a shorter period (5 h) to test the applicability and reliability of a new method for monitoring pollinators. The data were automatically entered and processed using R‐scripts after manual filtering of the images, obviating the need for manual data entry prior to analysis. For diel activity in bumblebees, the model that gave the best fit included the 24‐h fundamental period and one harmonic, a 12‐h period to modulate the signal, together with temperature. The bumblebees were exclusive diurnal, with activity starting about 5 h after sunrise, peaking sharply in the afternoon and ending about 1 h before sunset. In addition to time of day, activity also increased with temperature. The off‐the‐shelf digital camera , Canon PowerShot ® , with motion detection script, was triggered by every flower‐visiting honeybee. In addition to recorded visitor frequency and visitor duration, it enabled high‐resolution images, which could be important for species identification. Automatic camera recording is advantageous for close‐up monitoring, compared with continuous video recording, because the latter demands more time and effort in reviewing the material. It could be used to study a range of different species such as pollinators, on‐plant behaviour of herbivorous animals, cavity dwellers or cavity breeders. Moreover, the procedures for automatic data entry, data processing and statistical analysis for modelling diel activity rhythms could have great relevance for researchers using other types of camera monitoring systems operating 24 h per day.

COCOA AND TOTAL SYSTEM YIELDS OF ORGANIC AND CONVENTIONAL AGROFORESTRY VS. MONOCULTURE SYSTEMS IN A LONG-TERM FIELD TRIAL IN BOLIVIA

Article

Aug 2016

SUMMARY Cocoa ( Theobroma cacao L.) is produced in systems of varying complexity ranging from monoculture with temporary shade to highly diverse agroforests. Producers have to weigh high cocoa yields in the short to medium term in monocultures against higher total system yields in the short term and sustainable production systems in the long term in conjunction with ecosystem services in agroforestry systems (AFs). More long-term data on the comparative agronomic, economic and ecological performance of differently managed cocoa production systems is required to make sound recommendations to farmers. This paper describes the only long-term field trial worldwide comparing different cocoa production systems under conventional and organic management. The factors (i) crop diversity (monoculture vs. agroforestry), (ii) management practice (conventional vs. organic) and (iii) cultivar are being tested in a full-factorial, randomized complete block design with four replications. First, results showed significantly faster development of trunk circumferences in monocultures (+21%) compared to AFs. Cocoa yields were 47% lower in the organic compared to the conventional monoculture. In the AFs, however, the organic–conventional yield gap was less pronounced (−16%) and statistically insignificant. The cumulative yields of all products harvested were significantly higher in the AFs (+161%) compared to the monocultures. The productivity of cocoa by-crops in AFs may contribute to local food security and risk distribution in smallholder contexts.

Factors influencing quality variation in cocoa (Theobroma cacao) bean flavour profile - A review

Article

Jan 2016
FOOD RES INT

Effects of Foliar Applications of Selected Insecticides on Cocoa Pests and Pollinators

Article

Jan 1990

Abdul Ghani Ibrahim

The Ineffectiveness of the Stingless Bee Trigona jaty (Hymenoptera: Apidae: Meliponinae) as a Pollinator of Cocoa (Theobroma cacao L.)

Article

Apr 1981

Allen M. Young

The stingless bee Trigona jaty frequently visits cocoa (Theobroma cacao) flowers in Central America. In some plantations, it is common and collects much pollen throughout the year. Experiments were conducted in a plantation in northeastern Costa Rica to examine the role of T jaty as a pollinator of cocoa. The behaviour of a thriving colony was observed on two cocoa trees in a large screen cage and flower drop and fruit set were compared with those of two enclosed trees without bees in a similar cage. Flower drop and fruit set on branches exposed and protected from bees were also examined. It was concluded that T jaty is not an effective pollinator of cocoa because of its behaviour in removing excessive pollen which does not change even when the ratio of bees to flowers is low. Bees collect pollen peripherally from flowers, precluding any contact with the centrally-located stigma. The bees remove much pollen from cocoa flowers, an activity that perhaps reduces the attractiveness of flowers to other insects that might be effective pollinators.

Seasonal Differences in Abundance and Distribution of Cocoa-Pollinating Midges in Relation to Flowering and Fruit Set Between Shaded and Sunny Habitats of the La Lola Cocoa Farm in Costa Rica

Article

Dec 1983

Allen M. Young

Two of the most abundant midge species in the treatments, Forcipomyia youngi and F. quatei, the former a species new to science, were demonstrated to be effective cocoa pollinators. Absence of well developed shade cover in the sunny habitat intensifies the negative effect of the dry period on midge population dynamics while such an impact is less pronounced in the shaded habitat. Comparison of fruit set on individual cocoa Theobroma cacao trees near and away from places where midge densities were greatly increased fails to demonstrate statistically a positive correlation between increased pollinator abundance and fruit set, although the trend towards such a relationship is evident. The dry season may be a limiting factor of pollinating midge populations, particularly when shaded cover is not well developed, but use of rotting banana tree trunks greatly enhanced pollination. -from Author

THE OCCURRENCE OF INSECTS AND MOULDS IN STORED COCOA BEANS AT SOUTH SULAWESI

Article

Surveys on postharvest handling and technology processing of cocoa beans at farmer, trader and exporter levels in South Sulawesi were conducted together with investigations on moisture content, pest infestation (insect and mould) and quality characteristics in terms of reducing sugar, free amino acid and free fatty acid content. Surveys were conducted during dry (July 1997) and wet seasons (February 1998) in three regencies (Pinrang, Polewali-Mamasa and Luwu) and Ujung Pandang, South Sulawesi province. Interviews were carried out during surveys in the dry season. Number of respondents from farmers, trailers and exporters was 38, 15 and 5, respectively. In each season, number of samples taken from farmers, traders and exporters was 9, 21 and 15, respectively. In general, farmers, traders and exporters did not carry out postharvest handling and technology processing properly. Moisture content of cocoa beans collected from farmers, traders and exporters were higher than the tolerable limit recommended by SNI (7.5%). Moisture content of cocoa beans collected during the wet season was higher than in the dry season. Insects were found on cocoa beans collected from traders and exporters. Species composition and the presence of each insect species were varied among the two seasons, but the predominant species was Tribolium castaneum. At trader level the percentage of insect-damaged beans during the wet season was higher than that during the dry season, while at exporter level it was lower. During the two seasons the percentage of mouldy beans at farmer level was lower than the tolerable limit recommended by SNI (4%), while those from some samples at trader and exporter levels were higher than 4%, but based on the direct plating method, all of the samples at trader and exporter levels were mouldy. Species composition and the percentage of beans infected by each mould species at farmer, trader and exporter levels during the two seasons were varied. The percentage of mouldy beans increased at trader and exporter levels. The predominant moulds were Aspergillus flaws, Eurotium amstelodami, E. chevalieri and Penicillium citrinum. The predominant mould at farmer level during wet season was Saccharomyces cerevisiae (yeast). Reducing sugar and free amino acid content of cocoa beans collected during the dry season was higher than those collected during the wet season, either at farmer, trader or exporter levels. Free fatty acid content of cocoa beans tends to be higher during the wet season than the dry season at the three levels.

Effects of Shade Cover and Availability of Midge Breeding Sites on Pollinating Midge Populations and Fruit Set in Two Cocoa Farms

Article

Apr 1982

Allen M. Young

The abundance of several species of Forcipomyia midges (Diptera: Ceratopogonidae), known to be pollinators of cocoa Theobroma cacao increased markedly in one cocoa farm when discs of rotten banana stems were added to the ground-litter, but not in another. The increase in numbers of midge larvae and pupae associated with rotten banana stems occurred in a farm that had a shade cover consisting of an open canopy of bananas mixed with various wild trees, produced many cocoa flowers, and had a large number of midge species. The other farm had a uniform and homogenous shade cover of Hevea rubber trees, produced few cocoa flowers, and had only a few species of the midges.-from Author

Conserving Biodiversity Through Certification of Tropical Agroforestry Crops at Local and Landscape Scales

Article

Jan 2015

Voluntary sustainability standards and certification offer a promising mechanism to mitigate the severe negative impacts of agricultural expansion and intensification on tropical biodiversity. From a conservation standpoint, certification of tropical agroforestry crops, especially coffee and cocoa, is of particular interest given the potentially high biodiversity value of agroforestry systems and the substantial market penetration of coffee and cocoa certification in recent years. Here, we review experience with coffee and cocoa certification, summarize evidence on conservation impacts, and explore future needs. While there is much evidence that environmental criteria behind certification support biodiversity conservation, it is often unclear whether certification in fact promotes conservation-friendly farm management. Additionally, the farm-scale focus of current certification models may limit delivery of biodiversity conservation benefits, as maintenance of biodiversity depends on processes at larger landscape scales. To address this scale mismatch, we suggest that investment and innovation in certification over the next decade prioritize landscape conservation outcomes. This may be achieved by (i) linking existing certification mechanisms with broader landscape and ecosystem service management approaches and/or (ii) expanding current certification models to consider the landscape itself as the certified unit.This article is protected by copyright. All rights reserved.

Predicting the future climatic suitability for cocoa farming of the world's leading producer countries, Ghana and Côte d'Ivoire

Article

Aug 2013

Ghana and Côte d’Ivoire are the world’s leading cocoa (Thebroma cacao) producing countries; together they produce 53 % of the world’s cocoa. Cocoa contributes 7.5 % of the Gross Domestic Product (GDP) of Côte d’Ivoire and 3.4 % of that of Ghana and is an important cash crop for the rural population in the forest zones of these countries. If progressive climate change affected the climatic suitability for cocoa in West Africa, this would have implications for global cocoa output as well as the national economies and farmer livelihoods, with potential repercussions for forests and natural habitat as cocoa growing regions expand, shrink or shift. The objective of this paper is to present future climate scenarios for the main cocoa growing regions of Ghana and Côte d’Ivoire and to predict their impact on the relative suitability of these regions for growing cocoa. These analyses are intended to support the respective countries and supply chain actors in developing strategies for reducing the vulnerability of the cocoa sector to climate change. Based on the current distribution of cocoa growing areas and climate change predictions from 19 Global Circulation Models, we predict changes in relative climatic suitability for cocoa for 2050 using an adapted MAXENT model. According to the model, some current cocoa producing areas will become unsuitable (Lagunes and Sud-Comoe in Côte d’Ivoire) requiring crop change, while other areas will require adaptations in agronomic management, and in yet others the climatic suitability for growing cocoa will increase (Kwahu Plateu in Ghana and southwestern Côte d’Ivoire). We recommend the development of site-specific strategies to reduce the vulnerability of cocoa farmers and the sector to future climate change.

Global Food Security, Biodiversity Conservation and the Future of Agricultural Intensification

Article

Jul 2012
BIOL CONSERV

Under the current scenario of rapid human population increase, achieving efficient and productive agricultural land use while conserving biodiversity is a global challenge. There is an ongoing debate whether land for nature and for production should be segregated (land sparing) or integrated on the same land (land sharing, wildlife-friendly farming). While recent studies argue for agricultural intensification in a land sparing approach, we suggest here that it fails to account for real-world complexity. We argue that agriculture practiced under smallholder farmer-dominated landscapes and not large-scale farming, is currently the backbone of global food security in the developing world. Furthermore, contemporary food usage is inefficient with one third wasted and a further third used inefficiently to feed livestock and that conventional intensification causes often overlooked environmental costs. A major argument for wildlife friendly farming and agroecological intensification is that crucial ecosystem services are provided by “planned” and “associated” biodiversity, whereas the land sparing concept implies that biodiversity in agroecosystems is functionally negligible. However, loss of biological control can result in dramatic increases of pest densities, pollinator services affect a third of global human food supply, and inappropriate agricultural management can lead to environmental degradation. Hence, the true value of functional biodiversity on the farm is often inadequately acknowledged or understood, while conventional intensification tends to disrupt beneficial functions of biodiversity. In conclusion, linking agricultural intensification with biodiversity conservation and hunger reduction requires well-informed regional and targeted solutions, something which the land sparing vs sharing debate has failed to achieve so far.

Floral Nectaries and Trichomes in Relation to Pollination in Some Species of Theobroma and Herrania (Sterculiaceae)

Article

Apr 1984

Flowers are structurally complex and have sheltered reproductive parts indicating an elaborate insect-mediated pollination mechanism. Analysis of anther dehiscence, anthesis and pollen tube growth suggests a crepuscular pollination strategy. Suspected pollinators have been observed on floral parts of theobromas possessing stomate type nectaries and various shaped trichomes (blade of petal ligule and adaxial surface of petal hood). H. purpurea has elongate ligules devoid of stomates. In numerous spp. of theobromas, except T. cacao, and two species of Herrania, a conspicuous ring of multicellular trichomes occurs at the adaxial base of the sepals. A possible function for the ring may be fragrance production. -from Authors

Cherelle wilt of cacao: II. Wilt in relation to yield

Article

Sep 1960

A. D. McKELVIE

Experiments were carried out to study whether cherelle wilt is responsible for loss of yield in cacao. It was found that increasing or decreasing flower setting had no effect on yield as the crop was unrelated to the number of cherelles formed. Preventing setting till after the April ‘flush’ had no effect on yield. Variations in wilt between and within selections were studied, and it was concluded that yield is dependent on the nutrient status of the tree and independent of fluctuations in cherelle wilt.

Self and Cross-Fertilization in Plants. II. The Selection of Self Fertilization

Article

Sep 1992

David G. Lloyd

Presents a phenotypic model of the selection of self-fertilization that applies to any mode of self-pollination. A novel factor, seed discounting (loss of outcrossing maternal fitness accompanying an increase in self-fertilization) is introduced, and pollen discounting is reformulated. The model incorporates the effects of five principal factors - the cost of meiosis, inbreeding depression, reproductive assurance, and seed and pollen discounting. Either complete cross- or self-fertilization is selected, depending on the values of the parameters, but a number of additional factors can lead to intermediate frequencies of self-fertilization. Specific conditions for the selection of each mode of chasmogamous self-pollination and the effects of some special circumstances are derived by substituting the appropriate values of seed and pollen discounting in the general model. Geitonogamy and facilitated selfing are primarily nonadaptive by-products of mechanisms for outcrossing. Delayed selfing is most advantageous, but competing and prior selfing may be selected when structural constraints prevent delayed selfing or the prepotency of outcrossed pollen reduces seed discounting. The model predicts environmental modification of the frequency of self-fertilization and can explain the observed associations between frequent self-fertilization and both the annual habitat and poor conditions for cross-pollination. -Author

Cocoa Flower Diptera; Their Identity, Pollinating Activity and Breeding Sites

Article

Mar 1978

J. A. Winder

The Diptera associated with cocoa flowers throughout the world, their pollinating activity and known breeding sites are reviewed, and the disadvantages of using cages for assessing pollinating potential are discussed.

Entomology of the Cocoa Farm

Article

Nov 2003

Dennis Leston

planting before the first crop can be harvested. This review is therefore largely of entomo logical problems encountere d in Africa where the facts "are well-documented, thanks mainly to the outstanding work of scientist s associated with the West African Cocoa Research Institute" (19). In Cameroun and Cote d'Ivoire, cocoa is often a plantation crop but in

Ecological Intensification: Harnessing Ecosystem Services for Food Security

Article

Nov 2012
TRENDS ECOL EVOL

Rising demands for agricultural products will increase pressure to further intensify crop production, while negative environmental impacts have to be minimized. Ecological intensification entails the environmentally friendly replacement of anthropogenic inputs and/or enhancement of crop productivity, by including regulating and supporting ecosystem services management in agricultural practices. Effective ecological intensification requires an understanding of the relations between land use at different scales and the community composition of ecosystem service-providing organisms above and below ground, and the flow, stability, contribution to yield, and management costs of the multiple services delivered by these organisms. Research efforts and investments are particularly needed to reduce existing yield gaps by integrating context-appropriate bundles of ecosystem services into crop production systems.

The Economic Value of Ecological Services Provided by Insects

Article

Jan 2009

John E. Losey

In this article we focus on the vital ecological services provided by insects. We restrict our focus to services provided by “wild” insects; we do not include services from domesticated or mass-reared insect species. The four insect services for which we provide value estimates—dung burial, pest control, pollination, and wildlife nutrition—were chosen not because of their importance but because of the availability of data and an algorithm for their estimation. We base our estimations of the value of each service on projections of losses that would accrue if insects were not functioning at their current level. We estimate the annual value of these ecological services provided in the United States to be at least $57 billion, an amount that justifies greater investment in the conservation of these services.

The role of non-dipterous insects in the pollination of cocoa in Brazil

Article

Dec 1978
B ENTOMOL RES

J. A. Winder

Field collections in Bahia State, Brazil, of open cocoa flowers from an untreated plantation and one treated with insecticide and fungicide showed that Homoptera, including the cicadellid Xesrocephalus ancorifer Linnavuori, the aphidid Toxoptera aurantii (Boy.), and species of Pseudococcidae and Margarodidae (Coccoidea), constituted 96% of the total number of insects collected. In the untreated area, Wasmannia rochai Ford formed 22% of the ants collected and Brachymyrmex pictus Mayr, Crernatogaster ? parabiotica Forel,Iridomyrmex sp., Pheidole sp. and Solenopsis sp., a further 48%, whereas in the treated area, 47% were C. parabiotica, 14% W. rochai and 9% B. heeri Forel. There was evidence of a mosaic distribution pattern for the ant species. No cocoa pollen was found on any of the insects collected. Total pollination ranged between 7·4 and 8·1 % and effective pollination between 3·7 and 2·8 % in the treated and untreated areas, respectively. Approximately 76% of the pollen masses were stylar, with 38% of the ball type and 54% of the smear type, whereas the 16% stigmatic pollen masses consisted of 63% ball and 29% smear types; 44% of the stigmatic pollinations were effective, compared with only 33 % of the stylar ones. Some quadrats were more attractive to pollinators than others, and there was a significant positive correlation between percentage effective pollination and insolation, probably due to the favourable effect of sunshine on Forcipomyia activity.

Habitat differences in cocoa tree flowering, fruit-set, and pollinator availability in Costa Rica

Article

May 1986
J TROP ECOL

Allen M. Young

Phenological patterns of flowering and fruit-set were studied in cocoa trees ( Theobroma cacao ) (Sterculiaceae) at monthly intervals in two contrasting habitats in Costa Rica for a one-year period. One of these habitats, a well-maintained plantation, had irregular and broken shade cover { Erythrina trees in particular) while in the other habitat, a ‘cocoa forest’, cocoa trees were heavily shaded by Huara crepitans (Euphorbiaceae). ‘Matina’ variety cocoa trees of about the same age (50–60 years) were censused in both habitats. Cocoa-pollinating midge (Diptera: Ceratopogonidae and Cecidomyiidae) availability was estimated by sampling immature stages in experimentally-distributed ground-cover breeding substrates, comparing overall abundances and species numbers between the two habitats over three census dates (dry, mid-rainy, and late-rainy seasons), along with examination of fungal-rotted (diseased) cocoa pods both on trees and the ground. Although total flower production was much greater in the plantation habitat, total production of new pods was similar between habitats. Flowering followed a cyclic temporal pattern in the forest but not in the plantation. Sudden leaf drop of forest shade trees in the dry season probably triggered a cyclic response in which flowering peaked in the first half of the rainy season. There was an inverse relation for frequencies of mature cocoa pods killed by squirrels and pathogenic fungi ( Monilia roreri and Phytophthora ) between the two habitats: squirrel-killed pods were far more abundant in the plantation than in the forest, and the opposite for fungus-killed pods. Fungus-killed but otherwise intact pods, and not squirrel-killed pods rotting on trees, were a major breeding site for midges, particularly during the late rainy season. Ceratopogonidae were most abundant in the dry season and frequently encountered in cocoa pod husks and banana tree trunk sections in both habitats, and much more so in the forest habitat. The abandoned cocoa plantation (cocoa forest) supported a more diverse assemblage of pollinating midges than the plantation. In the plantation but not in the forest, a negative correlation was discovered between distance from shade trees and the numbers of pods on trees, suggesting greater pollinating activity by midges in cocoa trees beneath shade trees than away from them. The uniform dense shade cover in the adjacent forest probably obliterated such a pattern.

Neglected pollinators: Can enhanced pollination services improve cocoa yields? A review

Abstract

No full-text available

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