Cacao diseases: a global perspective from an industry point of view

ABSTRACT Diseases of cacao, Theobroma cacao, account for losses of more than 30% of the potential crop. These losses have caused a steady decline in production and a reduction in bean quality in almost all the cacao-producing areas in the world, especially in small-holder farms in Latin America and West Africa. The most significant diseases are witches' broom, caused by Moniliophthora perniciosa, which occurs mainly in South America; frosty pod rot, caused by M. roreri, which occurs mainly in Central and northern South America; and black pod disease, caused by several species of Phytophthora, which are distributed throughout the tropics. In view of the threat that these diseases pose to the sustainability of the cacao crop, Mars Inc. and their industry partners have funded collaborative research involving cacao research institutes and governmental and nongovernmental agencies. The objective of this global initiative is to develop short- to medium-term, low-cost, environmentally friendly disease-management strategies until disease tolerant varieties are widely available. These include good farming practices, biological control and the rational or minimal use of chemicals that could be used for integrated pest management (IPM). Farmer field schools are used to get these technologies to growers. This paper describes some of the key collaborative partners and projects that are underway in South America and West Africa.     

Frosty pod of cacao: a disease with a limited geographic range but unlimited potential for damage

ABSTRACT Moniliophthora roreri, the cause of frosty pod rot (FP), is a specialized fungal pathogen (family Marasmiaceae) that invades only actively growing pods of cacao, Theobroma cacao, and related species of Theobroma and Herrania. FP damages pods and the commercially important seeds that some of these species produce. M. roreri was confined to northwestern South America until the 1950s. Its appearance in Panama in 1956 signaled a change in its geographic distribution. Now, it is found in 11 countries in tropical America. The fungus is currently in an active dispersal phase, possibly due to an increase in human-mediated spread. FP is more destructive than black pod (Phytophthora spp.) and more dangerous and difficult to control than witches' broom, caused by Moniliophthora (Crinipellis) perniciosa. The aggressiveness of M. roreri, its capacity to survive different environmental conditions, its rapid natural dispersal, its propensity for man-mediated dispersal, and the susceptibility of most commercial cacao genotypes, all indicate that FP presents a substantial threat to cacao cultivation worldwide.     

Cacao diseases: important threats to chocolate production worldwide

ABSTRACT Theobroma cacao, cacao, is an ancient, neotropical domesticate. It is now grown throughout the humid, lowland tropics and is the basis of a multibillion dollar confectionary trade. Diverse diseases impact production of the crop. They reduce yields by ca. 20%, but could cause far greater losses if certain highly damaging diseases were to become more widely distributed. Among the most potentially dangerous of these diseases are frosty pod, caused by Moniliophthora roreri, and witches' broom, caused by M. perniciosa (previously Crinipellis perniciosa). These two diseases occur only in the Western Hemisphere, and severe losses would follow their introduction to West Africa and Asia, where ca. 86% of all cacao production occurs. Elsewhere, Cacao swollen shoot virus and the damaging black pod agent, Phytophthora megakarya, are found in Western Africa; whereas vascular streak dieback, caused by Oncobasidium theobromae, is present only in Asia. Breeding programs are challenged by minimal resistance to some of the diseases. Progress that has been made is threatened by the "emergence" of other serious diseases, such as Ceratocystis wilt (Ceratocystis cacaofunesta). During this symposium, new insights are discussed on the biology, origins, pathology and phylogeny of the pathogens; as well as the biological, chemical and genetic management of the diseases that they cause.     

Relationships Between Black Pod and Witches'-Broom Diseases in Theobroma cacao

ABSTRACT Field observations were conducted from 1998 to 2001 at the International Cocoa Genebank, Trinidad, to evaluate 57 cacao clones for resistance to black pod (BP) and witches'-broom (WB) diseases (caused by Phytophthora sp. and Crinipellis perniciosa, respectively). Each month ripe pods were harvested and the number of healthy and diseased was recorded. The number of brooms on vegetative shoots was recorded three times a year on selected branches. Twenty-three clones showed less than 10% of infection for both BP and WB on pods. Among those, eight clones showed an absence of brooms on the observed branches: IMC 6, MAN 15/60 [BRA], PA 67 [PER], PA 195 [PER], PA 218 [PER], PA 296 [PER], PA 303 [PER], and POUND 32/A [POU]. Broad-sense heritability was estimated at 0.38 and 0.57 for WB disease on pods and shoots, respectively, and at 0.51 for BP disease. Genetic correlation between WB disease on pods and on shoots was low and estimated at 0.39, whereas the correlation between WB and BP diseases on pods was 0.48. To choose putative parents for breeding schemes, it is suggested that clones are first assessed for their level of resistance to WB on shoots, and the most promising individuals are screened for BP with a detached pods test. Further studies are needed to confirm whether the level of resistance to WB on pods can be predicted using an early test on seedlings.     

Cacao diseases-the trilogy revisited

ABSTRACT This paper reviews the significant advances by the diseases themselves, as well as by the scientists, in the intervening period since the disease trilogy was first delimited in 1989. The impact of these diseases, black pod, witches' broom, and frosty pod rot, has increased dramatically. In addition, there have been radical changes in the taxonomic profiles of these pathogens, which have been based on both traditional (morphological, cytological) and modern (molecular) approaches. Black pod is caused by a complex of Phytophthora species, in which P. palmivora still is the most important worldwide. However, recent invasion of the principal cacao-growing countries of West Africa by the more virulent P. megakarya has been cause for concern. The latter evolved in the ancient forests straddling the Cameroon-Nigerian border as a primary coloniser of fallen fruit. Conversely, frosty pod rot, caused by Moniliophthora roreri, and witches' broom, caused by M. (Crinipellis) perniciosa, both neotropical diseases, are hemibiotrophic, coevolved pathogens. Respectively, M. roreri arose on Theobroma gileri in submontane forests on the north-western slopes of the Andes, whereas M. perniciosa developed as a complex of pathotypes with a considerably wider geographic and host range within South America; the cacao pathotype evolved on that host in the Amazon basin. The inter-relationships of these vicariant species and their recent spread are discussed, together with control strategies.     

Rapid Screening of Cacao Genotypes for Field Resistance to Phytophthora palmivora Using Leaves, Twigs and Roots

Black pod, caused by Phytophthora spp. is one of the most important diseases of cacao occurring worldwide. Losses due to black pod caused by P. palmivora are still moderate in Côte d'Ivoire but P. megakarya causes high losses in Ghana and other Central African countries. Variation in field attack has been observed between cacao genotypes, but evaluation of pod losses is unsuitable for obtaining rapid progress in breeding. Results of inoculation tests using young detached leaves, twigs and roots, obtained from field and nursery plants, are presented here and compared to field resistance of similar genotypes observed over a 10-year period. Nine different Upper Amazon Forastero genotypes were tested together with progenies obtained by crossing these with the susceptible check IFC5 (Amelonado genotype). Rank correlations between the early screening tests and the level of field attack were positive and mostly significant (r=0.58–0.95). The coefficient of correlation was slightly higher for leaves (r=0.88) and roots (r=0.89) than for twigs (r=0.76). Also, resistance of the different plant organs was correlated (r=0.6–0.9). Resistance of the Upper Amazon parents was well correlated with the resistance of their cross progenies (r=0.7–0.9), suggesting that resistance is highly heritable. Resistance of leaves and twigs from the nursery was better correlated with field resistance than resistance of leaves and twigs from the field, which might result from more uniform growing conditions in the nursery. Inoculation of leaves appears the most suitable early screening method for black pod resistance. Application of this test in breeding more resistant cacao cultivars is discussed.     

Black pod: diverse pathogens with a global impact on cocoa yield

ABSTRACT Pathogens of the Straminipile genus Phytophthora cause significant disease losses to global cocoa production. P. megakarya causes significant pod rot and losses due to canker in West Africa, whereas P. capsici and P. citrophthora cause pod rots in Central and South America. The global and highly damaging P. palmivora attacks all parts of the cocoa tree at all stages of the growing cycle. This pathogen causes 20 to 30% pod losses through black pod rot, and kills up to 10% of trees annually through stem cankers. P. palmivora has a complex disease cycle involving several sources of primary inoculum and several modes of dissemination of secondary inoculum. This results in explosive epidemics during favorable environmental conditions. The spread of regional pathogens must be prevented by effective quarantine barriers. Resistance to all these Phytophthora species is typically low in commercial cocoa genotypes. Disease losses can be reduced through integrated management practices that include pruning and shade management, leaf mulching, regular and complete harvesting, sanitation and pod case disposal, appropriate fertilizer application and targeted fungicide use. Packaging these options to improve uptake by smallholders presents a major challenge for the industry.     

A disease and production index (DPI) for selection of cacao (Theobroma cacao) clones highly productive and tolerant to pod rot diseases

Frosty pod rot (FPR) (Moniliophthora roreri), along with black pod rot (Phytophthora species) and witches’ broom disease (Moniliophthora perniciosa) constitute the main phytosanitary problems limiting cacao (Theobroma cacao) production causing severe yield losses. One of the main sought after methods of pod rot management is the selection of tolerant cacao genotypes. Typically, the selection is carried out through the quantification of the percentage of diseased pods (PDP). However, PDP does not consider the relative productivity, or production potential (PT) of the genotype. Production potential can vary among cacao genotypes. Consequently, genotypes with similar PT can have similar or vastly different disease tolerance levels as measured by PDP. The disease and production index (DPI) was developed to integrate a genotype's tolerance to M. roreri and other diseases as measured by PDP, with its PT. Here, we evaluated the number of healthy pods, number of diseased pods, and weight of fresh seed for 29 clones grown in replicated five-tree plots over 4 years. The data obtained was used to calculate PDP and DPI for each clone for three different disease combinations: frosty pod rot alone, pod rots other than frosty pod rot, and the combination of all pod rots. Multivariate analysis verified that DPI discriminated between clones based on productivity and disease tolerance. Surprisingly, there was a close ranking of clones between resistance to FPR and resistance to all other pod rots. The DPI can be used in breeding programmes focused on the selection of high yielding disease-tolerant cacao genotypes.     

Molecular characterization of fungal endophytic morphospecies isolated from stems and pods of Theobroma cacao

Endophytic fungi were isolated from healthy stems and pods of cacao ( Theobroma cacao ) trees in natural forest ecosystems and agroecosystems in Latin America and West Africa. These fungi were collected for screening as a potential source of biocontrol agents for the basidiomycetous pathogens of cacao in South and Central America, Moniliophthora roreri (frosty pod rot) and Moniliophthora perniciosa (witches' broom). Many of these isolates were morphologically unidentifiable as they failed to form fruiting structures in culture, or only produced arthrosporic stages. Affinities with basidiomycetes were suspected for many of these based on colony morphology. Fifty-nine of these morphologically unidentifiable isolates were selected for molecular identification by DNA extraction and sequence analysis of nuclear ribosomal DNA (rDNA). The large subunit (LSU) was chosen for initial sequencing because this region has been used most often for molecular systematics of basidiomycete fungi, and comprehensive LSU datasets were already available for sequence analyses. Results confirmed that the majority of the isolates tested belonged to the Basidiomycota, particularly to corticoid and polyporoid taxa. With LSU data alone, identification of the isolates was resolved at varying taxonomic levels (all to order, most to family, and many to genus). Some of the isolates came from rarely isolated genera, such as Byssomerulius , whilst the most commonly isolated basidiomycetous endophyte was a member of the cosmopolitan genus Coprinellus (Agaricales). The role of these fungi within the host and their potential as biological control agents are discussed.     

Phylogeny of the frosty pod rot pathogen of cocoa

Morphological, cytological and molecular evidence is presented which confirms that the frosty pod rot pathogen of cocoa, formerly classified as the mitosporic fungus Moniliophthora roreri (Deuteromycota), belongs to the hymenomycetous genus Crinipellis (Basidiomycota) and that two varieties should now be recognized: Crinipellis roreri var. roreri and the new variety C. roreri var. gileri . The latter was collected on Theobroma gileri , an endemic tree of submontane forests in north-west Ecuador, and can be distinguished from Ecuadorian and Peruvian isolates from cocoa ( T. cacao ) on the basis of spore morphology, incompatibility and nucleotide sequence data. As with var. roreri , meiosis is shown to occur within the dispersive and infective spore stage of var. gileri and these meiospores are interpreted to represent a much modified probasidium. In addition, in a field inoculation experiment, an isolate from T. gileri proved to be noninfective to cocoa pods when compared with positive control strains isolated from T. cacao in western Ecuador and T. bicolor in eastern Ecuador. It is concluded that var. gileri is the vestigial progenitor of the frosty pod rot pathogen of cocoa, with a host range and distribution restricted to T. gileri in the mesic forests of north-west South America.     

Ceratocystis wilt of cacao-a disease of increasing importance

ABSTRACT Ceratocystis cacaofunesta (formerly C. fimbriata) causes a lethal wilt disease of cacao (Theobroma cacao) in the Caribbean and Central and South America. Recent studies employing phylogenetics, intersterility, and host range separate the cacao pathogen from other strains of the C. fimbriata complex. Ceratocystis wilt has been managed through genetic resistance, but the disease is an emerging problem in Bahia, Brazil, where it was recently introduced. Genetic studies indicate that populations of the fungus in Costa Rica, Colombia, and Bahia may have been introduced on cacao cuttings; whereas populations in Rond?nia, Brazil, and western Ecuador appear to be native. The fungal genotype present in Bahia is similar to those found in Rond?nia and may have been introduced on propagative material with witches' broom resistance.     

Activity of Bacillus thuringiensis toxins against cocoa pod borer larvae

Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of cocoa pod borer cause the pods of the cocoa tree to ripen prematurely. They are difficult to control with conventional measures. Preliminary assays identified five toxins that were more active than others. In two subsequent bioassays the activity of selected toxins was determined more accurately. Three Cryl proteins with relatively little homology were all found to be toxic, opening perspectives for controlling cocoa pod borer by expression of Cry proteins in transgenic plants.     

Phytophthora resistance in cacao (Theobroma cacao): Influence of pod morphological characteristics

Twelve diverse cacao ( Theobroma cacao ) genotypes were assessed for pod resistance to Phytophthora palmivora at the penetration and post-penetration stages of infection using two inoculation methods. Correlation analysis between a number of pod characteristics (stomatal frequency, stomatal pore length, surface wax, thickness of exocarp/endocarp, hardness of exocarp/mesocarp, moisture content) and resistance indicated a strong relationship between resistance to lesion establishment (lesion frequency) and the joint effect of stomatal frequency and pore length. The epidermal impressions of the pod surfaces bearing germinating zoospores of P. palmivora provided evidence that penetration occurs through stomata, epidermal hair base, scar and by direct penetration. A poor correlation was obtained between the pod characteristics studied and post-penetration resistance, suggesting that this resistance, assessed by lesion size, is not governed by morphological or physical characteristics of the pod, but probably by biochemical factors. The importance of these findings in breeding of cacao for resistance to P. palmivora is discussed.     

Isolation of actinomycetes and endospore-forming bacteria from the cacao pod surface and their antagonistic activity against the witches’ broom and black pod pathogens

In this study, actinomycetes and endospore-forming bacteria were isolated from the surface of cacao pods. The activity of these microorganisms againstCrinipellis perniciosa andPhytophthora palmivora, causal agents of witches’ broom and black pod diseases of cacao, respectively, was investigated. A total of 336 isolates of actinomycetes and endosporeforming bacteria were tested on a detached pod assay againstC. perniciosa. The screening procedure used proved to be fast and inexpensive, allowing the selection of five actinomycetes as the most promising isolates for the biocontrol ofC. perniciosa. Under laboratory conditions the actinomycetes were able to inhibit 100% ofC. perniciosa basidiospore germination. However, under field conditions the selected actinomycetes were unable to protect cacao pods against both pathogens. In these experiments, inhibition ofC. perniciosa ranged from 6% to 21% in relation to the control, whereas there was no inhibition of black pod caused byP. palmivora. Formulations need to be improved in order to enhance the activity of the actinomycetes against cacao pathogens in the field. Molecular identification of the selected isolates showed that they are species of the genusStreptomyces.     

麦瘟病研究新进展

麦瘟病是1985年在南美洲出现的一种小麦真菌病害,目前已成为南美洲的主要小麦病害之一。在麦瘟病发病严重区域该病害可导致小麦减产高达100%,抗麦瘟病的小麦资源和基因少,且麦瘟病菌对甲氧基丙烯酸酯(QoIs)类杀菌剂具有较强的耐受性,监测、延缓、抑制其传播对有效控制麦瘟病意义重大。2016年和2018年发生了两次重要的麦瘟病扩散事件,受到广泛关注,两次扩散事件导致麦瘟病分别蔓延至亚洲孟加拉国和非洲赞比亚,麦瘟病的持续蔓延对全球小麦生产安全带来严重威胁。我国科学家与世界同行一道,在病害监测、小麦抗病资源和基因发掘、抗病品种的培育、病原菌生物学等方面的研究均取得了进展。本文从麦瘟病的传播历史、防控方法、国际国内开展麦瘟病相关研究工作进展等方面对麦瘟病进行综述;同时,也为我国应对麦瘟病威胁提供了策略、提出了应对建议。     

Biodiversity and biogeography of the cacao (Theobroma cacao) pathogen Moniliophthora roreri in tropical America

Moniliophthora roreri , the cause of moniliasis or frosty pod rot, occurs on the neotropical rainforest genera Theobroma and Herrania . While this basidiomycete has had devastating effects on the cacao tree ( T. cacao ) in tropical America, where it is confined, little is known of its biogeography and intraspecific genetic variability. Here, AFLP and ISSR profiles of 94 isolates of M. roreri from across its geographic range in Central/South America were analyzed. The study provided limited evidence to support the hypothesis that M. roreri is capable of sexual reproduction. The highest levels of genetic diversity occurred in Colombia and not in Ecuador as originally believed. The fungus was broadly divided into five genetic groups. Two of these have a wide geographic range: Bolívar group (north of Santander in Colombia, eastern Venezuela, peripheral Ecuador, Peru), and Co-West group (western Colombia, central Ecuador, Central America). The other groups are all apparently endemic to Colombia (Co-East and Co-Central groups) or north-western Ecuador ( Gileri group). We speculate that central/north-eastern Colombia may represent the centre of origin for M. roreri . Sequence data from the internal transcribed spacer region of the nuclear rDNA repeat were congruent with the AFLP/ISSR results, dividing M. roreri into two broad groups: the Orientalis group, comprising most isolates from the Co-East, Co-Central and Bolívar groups, and the Occidentalis group, comprising isolates from the Co-West and Gileri groups. The spread of M. roreri into new areas and countries mediated by human activity is discussed.     

Foliar resistance of cacao (Theobroma cacao) to Phytophthora palmivora as an indicator of pod resistance in the field: interaction of cacao genotype, leaf age and duration of incubation

The effects were studied of four leaf development stages (LDS) and three durations of incubation (DI) on the accuracy of leaf-disc tests on eight cacao (cocoa) clones (C) for predicting field resistance to phytophthora pod rot caused by Phytophthora palmivora . The clones were known to possess different general combining abilities (GCA) for pod resistance in the field, evaluated monthly at harvest over a 9-year period. Disease severity (DS) was affected strongly by C, DI and LDS, with increasing levels of significance. Two- and three-way interaction effects were smaller than the clone effect, but still significant. Clone effects were most significant for LDS3 (i.e. leaves 50–60 days old) and for DI5 and DI7 (observations made 5 and 7 days after inoculation, respectively). Coefficients of rank correlation between DS and field results were significant for seven of the 12 treatments, with highest values obtained again for treatments LDS3/DI5 ( r = 0·87) and LSD3/DI7 ( r = 0·93). Pooling of data for different LDS and DI treatments did not further improve the correlation with field results. However, these correlations were improved (from an average of 0·74 to 0·88) when the GCA values for field resistance were based on weekly observations, carried out in one year, including losses of pods and cherelles. It was concluded that, when carried out in a standardized manner and under optimal conditions, the leaf-disc test may explain 75–90% of the genetic variation for field resistance of cacao genotypes to P. palmivora .     

Of mushrooms and chocolate trees: aetiology and phylogeny of witches' broom and frosty pod diseases of cacao

The troubled history of the two major diseases of the chocolate tree (Theobroma cacao) in South America, witches' broom and frosty pod, is reviewed, concentrating on critical aspects of the aetiology as well as the phylogeny of the causal agents. Both diseases are caused by sister species within the genus Moniliophthora, belonging to the Marasmiaceae family of mushrooms. The witches' broom pathogen, Moniliophthora perniciosa, evolved on the Amazonian side of the Andes and induces brooms not only in cacao and its relatives in the genera Theobroma and Herrania (Malvaceae), but also in species in the plant families Bignoniaceae, Malpighiaceae and Solanaceae, on which the mushrooms (basidiomata) are produced. Moniliophthora roreri, the type species of the genus, evolved as a pod pathogen on endemic Theobroma species on the western side of the northern Andean Cordillera. Because Moniliophthora was described originally as the asexual form of an unknown basidiomycete, the generic diagnosis is amended here to accommodate species with agaricoid basidiomata. In addition, the new variety M. roreri var. gileri is designated for the morphotype occurring on Theobroma gileri, in northwest Ecuador. Cytology studies indicate that the supposed conidia of M. roreri are, in fact, sexual spores (meiospores) and it is posited that the fruiting structure represents a much‐modified mushroom. Finally, based on preliminary data from pathogenicity testing, it is hypothesized that the true causal agent of both diseases is an as yet unidentified infectious agent vectored into the host by the fungus.     

Diversity and pathogenicity of the Ceratocystidaceae associated with cacao agroforests in Cameroon

Knowledge of the diversity and ecology of plant pathogenic fungi in cacao agroforests and surrounding natural ecosystems can inform the development of sustainable management strategies for new cacao disease outbreaks. This study investigated the occurrence of fungi related to the Ceratocystidaceae and their nitidulid beetle vectors in cacao agroforests in Cameroon, under diverse agroecological conditions. The fungi and their vectors were collected from artificially induced stem wounds on cacao and associated shade trees. Collections were also made from abandoned cacao pod husks and other tree wounds within and around plantations. Fungal isolates were identified using DNA sequence‐based phylogenies and morphological comparisons, and two representatives of each species were evaluated for pathogenicity on cacao. Five species of Ceratocystidaceae were recovered, including Huntiella chlamydoformis sp. nov., H. pycnanthi sp. nov. and H. moniliformis, as well as Thielaviopsis cerberus and T. ethacetica. The incidence of these fungi appeared to be influenced by the prevailing agroecological conditions. Nitidulid beetles in the genus Brachypeplus were found to be their most common insect associates on cacao. Both T. ethacetica and H. pycnanthi produced extensive lesions after inoculation on branches of mature cacao trees, while T. ethacetica also caused pod rot. Although their impact remains unknown, fungi in the Ceratocystidaceae and their nitidulid beetle vectors are common and probably contribute to the parasitic pressure in Cameroonian cacao agrosystems.     

On-farm selection for quality and resistance to pest/diseases of cocoa in Sulawesi: (ii) quality and performance of selections against Phytophthora pod rot and vascular-streak dieback

The cocoa industry in Sulawesi, the main region of cocoa production in Indonesia, is threatened by destructive diseases, including vascular-streak dieback (VSD) caused by the basidiomycete Oncobasidium theobromae and stem canker and Phytophthora pod rot (PPR) or black pod, caused by Phytophthora palmivora. Using the considerable genetic diversity of cocoa on farms, host resistance was identified and tested with the participation of farmers. Forty-nine local and international cocoa selections with promising resistance characteristics (as well as susceptible controls) were side-grafted onto mature cocoa in a replicated trial with single-tree plots. Developing grafts were assessed in the dry season for severity of VSD infection, scored from 0 (no infection) to 4 (graft death). All of the 49 clones in the trial became infected with VSD in at least some replicates. Average severity varied from 0.2 to 1.6. Potential VSD-resistance was found in eight clones, including DRC 15, KA2 106 and a local Sulawesi selection, VSD2Ldg. Some of the most susceptible clones were local Sulawesi selections from areas with a history of little or no VSD. Thirty-four pod-bearing clones were evaluated over a 2-year period for yield, quality and resistance to natural infections of PPR. Cumulative PPR incidence for all clones was 22% but varied from 8.6 to 43% among clones. Clones with less than 15% PPR incidence were designated as resistant, including DRC 16 and local Sulawesi selections, Aryadi 1, Aryadi 3 and VSD1Ldg. Scavina 12 was moderately resistant in the trial with a PPR incidence of 23%. Cumulative incidences of the mirid, Helopeltis spp., determined in the same evaluation period, indicated that DRC16 was the most susceptible clone with an incidence of 52% in ripe pods and 23% in immature pods. In comparison, KKM4 showed evidence of resistance to Helopeltis spp., with incidences of 34 and 0.8% in ripe and immature pods, respectively. The impact of diseases and pests (including cocoa pod borer) on bean losses and bean quality varied between clones but generally the bean size (or bean count) was affected more than the fat content or shell content.