Cocoa Black Pod Research Articles

Knowledge and control of cocoa black pod disease and factors influencing the sourcing of planting material by smallholder farmers in Cross River State, Nigeria

ABSTRACT This study assessed the level of awareness and management of cocoa black pod disease and factors influencing the sourcing of planting materials by smallholder farmers in Cross River State, Nigeria. A questionnaire, designed to assess farmers’ knowledge and control measures, was administered to 200 cocoa farmers. The data collected were analyzed using descriptive statistics and a linear regression model to determine factors influencing planting material sourcing. The study revealed that the majority of farmers were small- or medium-scale, with a small household size, limiting the adoption of improved technology. A majority of smallholder farmers planted Amazon cocoa varieties while 21.4% of respondents did not know the variety of cocoa they planted. The majority of farmers used fungicides to control black pod disease, and respondents obtained cocoa planting materials from other farmers (71%) or from Cocoa Research Institute of Nigeria Stations and Agricultural Development Stations (29%). The study found that only three variables significantly predicted the source of cocoa planting materials: variety of cocoa planted, quantity of fungicide used per annum, and fungicide/harvest ratio. There is a need to extend agricultural development stations as well as increase extension services to help farmers getting improved cocoa varieties from authorized centers.

Sensitivity Analysis and Optimal Control of Cocoa Black Pod Disease Caused by Phytophora Margakarya

To address the critical threat black pod disease poses to global cocoa production and farmer income, this study developed a novel mathematical model that utilizes a system of ordinary differential equations to capture the interactions between various stages of cocoa pods (susceptible cherelles, young/mature pods, ripe pods) and their disease state (exposed, infected). Additionally, the model incorporates the dynamics of the disease-causing pathogen population. Employing Pontryagin's Maximum Principle, the model optimizes control strategies that minimize disease impact. This optimization identifies the efficient allocation of resources, timing of interventions, and deployment of control measures like infected pod removal, fungicides, and sanitation practices. The finding of the study reveals that control measure u3 which is rouging (pod removal) and any one of the remaining control measures is best for the treatment of cocoa black pod disease caused by Phytophora Megarkaya. These findings translate into valuable, data-driven recommendations for cocoa farmers and disease management professionals. By strategically combining infected pod removal, targeted fungicide use, and environmental management practices, farmers can significantly reduce disease severity, enhance cocoa production, and promote a more sustainable cocoa industry.

Anti-black pod disease activity of leaf extract of Carica papaya Linn

BackgroundTheobroma cacao (Cocoa) is a major foreign exchange earner for Ghana. Over the recent decades, there has been a consistent decline in cocoa production in the country. A major contributing factor is the cocoa black pod disease caused by Phytophthora species. Synthetic fungicides have been used to control the pathogens over the years. However, recent calls for organic cocoa devoid of residues from synthetic fungicides, which are known to pose several health challenges as well as a negative impact on the environment, have gained attention. Thus, inviting investigations into more environmentally friendly and sustainable alternatives to synthetic fungicides. ObjectiveThis study explored the inhibitory potential of crude extract from Carica papaya against cocoa black pod disease caused by Phytophthora spp. Material and methodsAn in-silico study was done using known phytochemicals from Carica papaya as ligands against a Phytophthora effector protein. Crude extracts were obtained from the plant materials using 70 % ethanol as the extraction solvent. The crude Green Leaf Extract (GLE), Aging Induced Chlorophyll Deficient Leaf Extract (AICDLE), and Matured Black Seed Extract (SDE) were tested in-vitro against pre-cultured P. palmivora and P. megakarya using the poison food technique. GLE was modulated with Delco, a synthetic fungicide, at different ratios which were tested in-vitro and in-vivo. ResultsA total of 16 ligands showed binding affinity higher or equal to the standard ligand, alliin, suggesting Carica papaya as a repository of anti-phytophthora agents. Assessment of crude extracts at concentrations 5–20 mg/ml showed fungistatic activity against P. palmivora and P. megakarya in-vitro. Modulation of GLE with Delco produced some combinations that made GLE fungicidal in-vitro against P. palmivora and P. megakarya with fractional inhibition concentration indices between 0.51 and 0.65, interpreted as partially synergistic. The in-vivo assessment of combination D (Delco and GLE in a 0.3 mg:3 mg per ml ratio) performed as well as Delco alone at the recommended dose of 5 mg/ml. Thus, combination D reduces the requirement for copper-based fungicide by over 90 %. ConclusionThis study shows Carica papaya in a new light as a potential material that could be formulated into a natural product-based fungicide for combating Phytophthora-induced black pod disease.

Optimal control of Cocoa Black pod disease: A multi-pronged approach

This study presents a novel approach to controlling cocoa black pod disease, caused by Phytophthora megakarya. Unlike previous methods, we employ a mathematical modeling framework based on Pontryagin’s Maximum Principle to optimize control strategies that minimize disease impact. The model incorporates the dynamics of healthy and infected pods while considering the combined effects of three key interventions: Infected pod removal, Targeted fungicide application and Promoting a healthy growing environment. Through numerical simulations, we identify the optimal timing and intensity for each intervention to minimize infected pods over time. This study highlights the following novelties: Synergistic effect of combined control which demonstrates that combining all three strategies is significantly more effective than relying on individual methods, Optimal strategies which involves dynamically adjusting control measures throughout the growing season to adapt to disease progression, Prompt action after disease detection proves crucial for successful control. These findings offer valuable data-driven recommendations for cocoa farmers and disease management professionals. By strategically implementing a combination of infected pod removal, targeted fungicide use, and environmental management, farmers can significantly reduce disease severity, enhance cocoa production, and promote a more sustainable cocoa industry.

The potential of Trichoderma asperellum organic extract and its emulsion to inhibit cocoa ( Theobroma cacao L.) black pod disease and induce biochemical defenses against Phytophthora megakarya

This work aimed to evaluate the potential of Trichoderma asperellum organic extract and its emulsion to control cocoa black pod disease caused by Phytophthora megakarya. Organic extract was obtained after fermentation of T. asperellum and its emulsion prepared by emulsification. The in vitro antimicrobial assays of organic extract and its emulsion were evaluated and the in situ tests were carried out on detached cocoa pods. T. asperellum inhibited the mycelia growth of P. megakarya at the rates of 52% and 100%, respectively, on dual culture and the cellophane plate. This antagonist produced lytic enzymes such as cellulase, amylase, lipase and protease. The organic extract contained alkaloid, flavonoid and phenol compounds. The emulsion obtained was stable. At 100 μg · ml -1, the extract and its formulation completely inhibited the mycelial growth of P. megakarya. Similarly, when infected detached cocoa pods were sprayed with extract or emulsion, there was a significant reduction of necrosis both for healing and prevention with the latter being the most efficient. For the preventive tests, the total inhibition was recorded at 3000 μg · ml -1 and 1000 μg · ml -1, respectively, with crude organic extract and its emulsion· For curative tests, total inhibition was obtained at 4000 μg · ml -1 and 3000 μg · ml -1, respectively, for preventive and curative tests. There was a significant and positive correlation between the content of biochemical markers and the reduction of necrosis on cocoa pods after treatment with the extract or its formulation. T. asperellum organic extract emulsion could be used as an alternative in the bio- protection of cocoa black pods disease.

Integrated Management of Black Pod (Phytophthora palmivora) Disease of Cocoa Through Fungicides and Cultural Practices in Southwestern Ethiopia

Black pod disease of cocoa (Theobroma cacao L.) caused by Phytophthora palmivora is the major constraint in cocoa production in southwestern Ethiopia. Therefore, integrated field management trials were conducted to evaluate the efficacy of different fungicides against a disease epidemic of cocoa black pod in southwestern Ethiopia. The field experiment was laid out in a randomized complete block design with seven treatments and three replications. The experiment was performed during the 2021 and 2022 main cropping seasons using five fungicides: Copper oxychloride (Koka blue 50 WG) combined with cultural practices, Agro-laxyl 63.5 WP (Metalaxyl + Mancozeb) combined with cultural practices, Progress 250 EC (Propiconazole 25%) combined with cultural practices, Ethiozeb 80% WP (Mancozeb) combined with cultural practices, More 720 WP (Mancozeb +Cymoxanil) combined with cultural practices, cultural practices alone and control without any cultural practices and fungicides spray for control of black pod infection. Cultural practices such as nutrient management, pruning, plant and field hygiene etc. were implemented in all treatments except control. The results of the experiment indicated that copper oxychloride (Koka blue 50 WG) combined with cultural practices significantly affected the cocoa black pod epidemics. When paired with cultural practices, copper oxychloride (Koka blue 50 WG) had a considerably greater impact on lowering disease severity (4.76) than the other treatments. Additionally, compared to control plots, the incidence of disease was reduced by more than 50% when cultural practices alone were used. This shows that in farms where black pod disease severity is low, the disease may be economically managed by implementing cultural measures alone. So, the the study's findings, black pod disease can be controlled in areas with a high disease incidence by combining the application of copper oxychloride (Koka blue 50 WG) with other cultural practices.

Mathematical Model for Spread and Control of Cocoa Black Pod Disease

Black pod disease is a major threat to cocoa production worldwide. A mathematical model for the spread of cacao black pod disease is presented in this article. The model takes into account several variables that influence the spread of the disease. A set of differential equations that are numerically solved using Runge-Kutta method embedded in MATLAB software are used to simulate the dynamics of disease transmission which form the basis of the model. Utilizing information from the literature and ecological observations from cocoa fields in West Africa, where black pod disease poses a serious threat to the production of cocoa, the model was verified. The model's outcomes highlight the significance of early detection and rapid intervention in mitigating the severity of cocoa black pod disease outbreaks. Moreover, it emphasizes the importance of adopting integrated disease management approaches that consider fungicide administration and removal of infected pods. The usefulness of mathematical modeling as a tool for understanding and managing cocoa black pod disease is illustrated by this study.

Screening of Trichoderma Isolates and Potential of Their Organic Extract to Control Phytophthora megakarya, the Causative Agent of Cocoa Black Pod Disease

The aim of this work was to isolate Trichoderma agents of cocoa trees and to select the best antagonists able to reduce cocoa black pod disease caused by Phytophthora megakarya. Sampling was carried out in the Western region of Cameroon, locality of Bafang. Trichoderma and P. megakarya isolates were made on PDA medium in a Petri dish. In vitro antagonist activity of Trichoderma was evaluated by dual culture and antibiosis tests, and the best isolates were selected. The production of hydrolytic enzymes by the best isolates was done in specific solid media. The antimicrobial effect of the crude organic extract extracted from the selected Trichoderma isolates was performed in vitro by poisoned method. Results showed that 12 Trichoderma spp were isolated. Based on the rating scale of Bell, 4 isolates were selected, namely IS4, IS7, IS9 and IS11. These isolates were found to produce non-volatile and volatiles compounds as well as hydrolytic enzymes (cellulase, amylase, lipase and protease); Their organic crude extract significantly inhibited the growth of mycelial of P. megakarya with IC7 as the best isolates. IS7 Trichoderma isolate significantly produced cellulase, amylase, lipase and protease and at 100μg/ml, its organic crude extract total inhibited the mycelial growth of P. megakarya. It could be suggested that, Trichoderma IS7 isolate should be further investigated as promising biocontrol agent to manage P. megakarya infection.

Adaptation strategies for the adverse effects of climate disruptions on coffee and cocoa trees productivity in Cameroon

The decline of Cameroon cocoa and coffee productions are increasingly designated as one of the negative consequences of climate change on plants development. The purpose of this study was to contribute to improving the productivity of cocoa and coffee trees, in their production areas, in Cameroon. Thus, 280 plots, located in three different agro-ecological zones, were monitored for five consecutive years (2014-2018). Meteorological data were also systematically collected at each site. Data analysis highlighted three classes of unstable meteorological profiles that reflect the non-recurrence of climatic events on the study sites. Multiple logistic regression analysis showed that the incidence of cocoa black pod disease and that of Arabica coffee berry disease increases with the quantity of rainfall and the number of rainy days. This increase rather induces a decrease in the attack rate of berry borer on the Robusta coffee trees. The results obtained made it possible to identify, by elucidating their respective roles, the climatic variables which have an effect on the productivity of cocoa and coffee trees. They have also led, for the first time, to the conceptualization of innovative technical processes, which can reduce the harmful effects of climatic disturbances on cocoa and coffee crops.

Early Cocoa Blackpod Pathogen Prediction with Machine Learning Ensemble Algorithm based on Climatic Parameters

Machine learning has been useful for prediction in the various sectors of the economy. The research work proposed an ensemble SA-CCT machine learning algorithm that gives early and accurate prediction of blackpod disease to farmers and agricultural extension officers in South-West, Nigeria. Since data mining put into consideration the types of pattern in a given dataset, the study considered the pattern in climatic dataset retrieved from Nigeria Meteorological agency (NIMET). The proposed model uses climatic parameters (Rainfall and Temperature) to predict the outbreak of blackpod disease. The ensemble SA-CCT model was formulated by hybridizing a linear algorithm Seasonal Auto Regressive Integrated Moving Average (SARIMA) and a nonlinear algorithm Compact Classification Tree (CCT), the implementation was done with python programming. The proposed SA-CCT model gives the following results after evaluation. Precision: 0.9429, Recall 0.9167, Mean Square Error: 0.2357, Accuracy: 0.9444

Phytophthora palmivora from Sulawesi and Java Islands, Indonesia, reveals high genotypic diversity and lack of population structure

Phytophthora palmivora is the causal agent of cocoa black pod disease, one of the primary diseases of cocoa in Indonesia. A better understanding of P. palmivora population genetics is needed to aid the development of relevant disease management strategies. This study is the first population genetic study of P. palmivora in Indonesia using microsatellite markers based on the alleles genotyping method. The microsatellite markers were used to determine the genotype of 44 P. palmivora isolates from Sulawesi (24) and Java (20) islands. The total number of observed multilocus genotypes (MLG) from both populations was 34. The genotypic diversity of P. palmivora from Sulawesi (2.90; 16.0; 0.938) and Java (2.76; 14.3; 0.930) islands was high as seen from Shannon's diversity index (H), Stoddart and Taylor's Index (G), and Simpson's Index (λ) respectively. Evenness and Nei's unbiased gene diversity exhibited similarly high levels from both populations. The linkage disequilibrium test indicated that sexual recombination occurred in the Java population (P = 0.312). Analysis of molecular variance (AMOVA) and Bayesian clustering revealed five genetic clusters, and isolates from both islands were evenly distributed across the five gene clusters. All genetic diversity was from within individuals. P. palmivora from Sulawesi and Java showed a high genotypic diversity but a lack of genetic differentiation among populations (Fst = 0.006). Both populations formed one highly diverse group. Minimum spanning network analysis showed no particular grouping of MLGs, and shared MLGs from both populations indicated long-distance migration of P. palmivora facilitated by human activities.

​Control Activity and Antibiotic Gene Detection of Endophytic Bacteria in Suppressing Cocoa Black Pod Disease (Phytophthora palmivora Butl.)

Background: Black pod rot disease of cocoa caused by (Phytophthora palmivora Butl.) is one of the major diseases on cocoa plantations worldwide. Many attempts have been made to prevent or reduce the infection of pathogens, but they have not provided optimum results. This study aims to detect antibiotic genes in endophytic bacteria that can suppress cocoa black pod disease. Methods: Eight endophytic bacteria were isolated from healthy cocoa pods and twigs that showed potentials in suppressing P. palmivora growth in vitro were used in suppressing of black pod rot disease in vivo tests. Antibiotic biosynthesis-related genes from eight endophytic bacterial isolates were confirmed by using PCR method, which includes phenazine-1-carboxylic (PCA), pyrrolnitrin (PRN), phenazine-1-carboxamide acid (PCN), pyoluteorin (PLT) and 2,4-diacetylphloroglucinol (DPAG/Phl). Result: The endophytic bacteria, 4RSI, 5BR B3 and 2RW B2 isolates showed the highest disease suppressing index to black pod rot disease in vivo, i.e., 70.27%, 70.08% and 56.64%. The isolates 5BR B3 and 2RW B2 DNA yielded PCR product by using PCA primers (1400 bp), PRN primers (700 bp) and DAPG primers (1600 bp), while the 5RSI isolate yield PCR product using PRN primers only. Endophytic bacterial isolates 5BRB3 and 2RW B2 provided partial disease suppression to pod rot disease by inhibit pathogen growth and antibiotic compounds production.

Parameter Estimation in a PDE Model for the Spatial Spread of Cocoa Black Pod Disease.

In this paper, we develop an epidemiological model with both environmental (primary infection from the environmental spores reservoir) and direct transmission (secondary infection from an infected host to a susceptible pod). This model simulates the spatiotemporal evolution of cocoa black pod disease caused by Phytophthora megakarya. Since reliable parameter estimation is a central issue for modeling realistic biological systems, we used a mechanistic-statistical approach to estimate model parameters from real observations of a specific cocoa plot. In addition, to refine numerical simulations of the pathosystem, data describing the shade intensity all over the plot were exploited and led to increased model predictions accuracy and also highlighted a higher number of infected pods located in areas of the plot with higher shading intensity. Recommendations in terms of promoting cocoa farming in systems with low shading intensity may be evident if these results are confirmed. Our results also highlight the importance of the environmental spore reservoir in black pod disease dynamics.

Endophytic fungi as potential biocontrol agents of Phytophthora palmivora in the cocoa plant

Abstract. Simamora AV, Hahuly MV, Henuk JBD. 2021. Endophytic fungi as potential biocontrol agents of Phytophthora palmivora in the cocoa plant. Biodiversitas 22: 2601-2609. In Indonesia, the cocoa tree is one of the essential cultivation crops for farmers. Despite the importance of cocoa cultivation in Indonesia's economy, the productivity of this crop has declined. Cocoa black pod disease caused by Phytophthora palmivora (Butl.) is one of the most severe diseases affecting this crop worldwide, with average annual losses above 40%. Instead of using manufactured chemicals, biological control is an effective and eco-friendly alternative control measure against plant pathogens. This work aimed to assess the potential of endophytic fungi isolated from healthy cocoa pods to control Phytophthora palmivora in vitro and in vivo. Endophytic fungal isolates were classified based on the morphological characteristics of their cultures and reproductive structures. All isolates found were tested to inhibit P. palmivora in the dual culture method, and the best 10 isolates were continued for detached pod assay. Then, the best five isolates (Aspergillus4, Aspergillus5, Aspergillus6, Fusarium6, Ramichloridium sp.) were evaluated for their capability to reduce P. palmivora in cocoa seedlings and in the field plants. Aspergillus, Fusarium, and Ramichloridium showed maximum activity against P. palmivora in dual culture, pod, and seedling assays. Nevertheless, when all these five isolates were applied in the field, they did not suppress the disease development.

Antifungal effect of the cumulative application of biostimulant and fertilizers on young cocoa fruits rot at Tafissou site, Centre-East of Côte d'Ivoire

The use of biostimulants as an alternative way to chemical, often toxic, remains one of the best approaches to control cocoa black pod disease caused by Phytophthora spp. This study has been carried out to evaluate the effect of biostimulant’s applications number and the cumulative action in case of applying previously fertilizers. The experimental design consisted of a Fischer block with six treatments (T01, T02, T1, T2, T3 and T4) and repeated three times. This design was replicated on two sites, one with previous fertilizer (DAE) and the other without previous fertilizer (DSE). Observations were made monthly on each test tree. The biostimulant Banzai was applied for 3 or 4 consecutive months depending on the treatment at each site. The data collected included the total number of cherelles produced and the number of rotten cherelles. From these, data were deduced the rates of healthy cherelles on which the Kruskal-Wallis test was applied to compare treatments between them and between sites. The results showed that four applications of the biostimulant with fertilizer provided better control than three applications without fertilizer. The results also showed that the majority of treatments at the DAE site were more effective than treatments at the DSE site. In conclusion, four applications Banzai coupled with fertilizer have achieved the best rates of healthy cherelles whatever the site. Regarding the cumulative effect of the previous fertilizer with Banzai, treatments of the site with the previous fertilizer were still better than the treatment site without fertilizer.

Management of Cocoa Black Pod Disease by Farmers in Edo State, Nigeria: The Role of Farmer Field School

The specific objectives of the study were to find the contribution of FFS training in control of the disease; examine the role of FFS in improving farmers’ competency in management of black pod disease, and determine the proportion of farmers that benefited from FFS training on management of black pod disease. A multi-stage sampling procedure was employed in selecting 76 FFS farmers and 74 other farmers, and various descriptive statistics and t-tests were used to analyze data. The results showed that FFS played a major role in improving FFS farmers’ competency in the management of black pod disease. The t-tests conducted showed significant differences in knowledge between FFS farmers and other farmers.

Assessing the effect of fungicide treatment on Cocoa black pod disease in Ghana: Insight from mathematical modeling

Black pod disease is caused by fungi of the species Phytophthora palmivora or Phytophthora megakarya. The disease causes darkening of affected areas of cocoa trees and/or fruits and leads to significant reduction in crop yields and decreases lifespan of the plant. This study presents a simple S_1S_2IT-type model with variable population size to assess the impact of fungicide treatment on the dynamics of the black pod disease. We do both theoretical studies and numerical simulations of the model. In particular, we analyze the existence of equilibrium points and their stability, simulate the model using data on reported black pod cases from Ghana. In addition, we perform sensitivity analysis of the basic reproduction number with respect to the model parameters. The results show that the top three parameters that govern the dynamics of the black pod disease are the treatment rate, transmission rate, and planting rate of new trees

Evaluation of the Epidemiological Factors Responsible for the Appearance of Phytophthora Palmivora and Phytophthora Megakarya, Causal Agent of Black Pods Disease in the Department of Méagui, Southwestern Côte D'ivoire

The cocoa black pod disease is caused by a fungus Phytophthora sp, which comprises two main species (Phytophthora palmivora and Phytophthora megakarya) commonly found in Ivorian cocoa plots and which cause significant damage. Despite numerous studies, this disease continues to spread and even more so Phytophthora megakarya, which did not exist in Côte d'Ivoire, is beginning to spread significantly. This study focused on the evaluation of the epidemiological factors responsible for the progression of Phytophthora megakarya and Phytophthora palmivora in the Department of Méagui, southwestern Cote d'Ivoire. To this end, a prospective survey was conducted in three cocoa plots in Méagui, which collected epidemiological data on

Antifungal Efficacy of Crude Aqueous Weed Extracts Against Pathogen of Cocoa Black Pod Rot

Black pod rot is the most economically important disease of cocoa in Malaysia which is mainly caused by a highly polyphagous Phytophthora species, called Phytophthora palmivora. The fungus could attack all parts of the cocoa plant organs and caused various diseases at any growth stage from seedling until the mature stages, especially during raining season. The application of synthetic fungicides has been widely recommended to manage the disease but their repeated use had led to other problems such as environmental, human health and development of fungicide resistance issues. This study isolated and identified Phytopththora isolate from a cocoa pod sample based on micro-morphological characters. Besides, the present investigation was undertaken to screen for the antifungal potency of different weed extracts against the Phytophthora pathogen using poisoned food technique. The fungal isolate was successfully recovered from pod tissues of clone PBC123 on 20% tomato juice agar culture (20T). Only one out of ten weed extracts tested showed a significant in vitro inhibitory effect towards mycelial growth of Phytophthora isolate, which was aqueous crude leaf extract of Solanum torvum (42.68%). This study indicated that the potential of weed extracts in the management of Phytophthora diseases, and may offer more natural, effective and economical control methods.

Antifungal Efficacy of Crude Aqueous Weed Extracts Against Pathogen of Cocoa Black Pod Rot

Salah satu daripada unsur utama keperluan hidup manusia adalah pemakanan. Pemakanan berperanan penting terhadap pembangunan insan sama ada pembangunan fizikal, spiritual, mental atau emosi. Konsep makanan dalam Islam diklasifikasikan kepada makanan halal, makanan makruh, makanan haram dan makanan syubhah. Amalan pemakanan halal amat ditekankan oleh Islam bertujuan untuk memastikan fizikal dan rohani umat Islam sentiasa harmoni, suci dan dicintai Allah SWT. Berbeza dengan amalan pemakanan haram yang banyak mengakibatkan kemudaratan kepada pemakannya. Antaranya, makanan itu akan mempengaruhi jiwa pemakannya sehingga dia lebih gemar melakukan maksiat dan benci akan ketaatan, mendatangkan bahaya serta memberi kesan buruk kepada fizikal dan mental. Selain daripada itu, amalan pemakanan secara melampaui batasan juga menyebabkan pelbagai jenis penyakit kepada pemakannya. Perkara ini dipaparkan di dalam alQuran dan Hadis. Kitab Fi Zilal al-Quran merupakan salah sebuah daripada kitab-kitab tafsir di pasaran yang banyak membantu umat Islam dalam memahami terjemahan dan tafsiran ayat-ayat suci al-Quran dengan jelas dan sempurna.