Cocoa Yield Research Articles

Soil Fertility Evaluation of Major Cocoa Producing Areas of Cross River State, Nigeria

Assessment of soil textures and fertility properties of major cocoa producing areas of Cross River State of Nigeria was carried out to ascertain their suitability for cocoa production. Thirty six (36) representative soil samples were collected between November 2016 and January 2017 from 18 selected cocoa farms in Boki, Ikom and Etung and analyzed using standard laboratory procedures. Result indicated textural classes of loamy sand, sandy loam sandy clay loam, sandy clay and clay loam soils in the cocoa farms with a mean clay 30.02 percent, silt 13.49% and sand 56.43 the result of the fertility properties of the soils show means in the ranges of pH (5,31-5.64), EC (0.021-0.023 ds/m), OM (2.81-3.36%)TN (0.07-0.09%), AV.P (2.82-5.92 mg/kg), exch Mg (1.47-200 cmol/kg) exchange Na (0.05-0.06 cmol/kg) ECEC (6.73-8.94 cmol/kg) BS (77.25-82.70%). In this study area base saturation, exchangeable calcium and magnesium and total nitrogen were adequate within recommended limit. Available phosphorus, potassium, organic matter electrical conductivity and effective cation exchange capacity were below the critical level. A guarded application of appropriate fertilizers in this cocoa growing area is recommended for sustainable yield of cocoa in quantity and quality.

Farmers\u2019 Perceptions as a Driver of Agricultural Practices: Understanding Soil Fertility Management Practices in Cocoa Agroforestry Systems in Cameroon

In Africa, cocoa yields are low, partly due to soil fertility constraints and poor management. While peoples’ knowledge, aspirations, and abilities are key factors explaining their behaviour, little is known about the rationales that underpin soil fertility management practices (SFMPs) of cocoa farmers. To address this gap, we conducted an exploratory survey in two contrasting regions in Cameroon where cocoa is an important crop: the humid forest and the forest-savannah transition zone. Some 30% of farmers in the transition zone as opposed to 13% in the humid forest expressed concerns about soil fertility. The most relevant soil fertility indicators for farmers were high cocoa yield, dark soil colour, ease of tillage, and floral composition. To enhance and maintain soil fertility, farmers used residues from weeding (100%), planting of trees (42%), mineral fertilisers (33%), compost (16%), and manure (13%). More farmers in the transition zone than the humid forest implemented SFMPs. Our findings suggest that soil fertility perceptions, access to inputs, local practices, and experience influence farmers’ use of SFMPs. The limited use of mineral fertilisers was explained by poor access whereas the use of organic fertilisers and tree planting were mostly constrained by lack of labour and knowledge. Farmers prioritised practices to increase yield and viewed SFMPs to be the least important management practices, although they believe high cocoa yield is an important indicator of soil fertility. To foster sustainable cocoa intensification, it is necessary to enhance farmers’ knowledge on SFMPs, increase access to inputs, and ensure returns on investment while considering farmers’ priorities and practices.

Evaluation of herbicides and manual weed control methods in the establishment of Theobroma cacao L. in Cross River State of Nigeria

Field trial was conducted at the Cocoa Research Institute of Nigeria (CRIN), Ajassor substation, Cross River State, Nigeria between 2015 and 2017 to evaluate the effect of different weed control methods on the growth and yield of cocoa during their early years of establishment. Glyphosate and paraquat were applied at 480, 720, 960 and 1440 gram of active ingredient per hectare using very low volume (g a.i. ha-1 vlv) while manual weeding (i.e. slashing with cutlass) was used as the control. A Nigeria commercial cocoa variety Tc series, also known as 18-month cocoa, was established at a CRIN recommended spacing of 3 x 3 m, laid out in a Complete Randomized Block Design with four replications. All young cocoa stands were ring weeded at 50 cm diameter and covered with black polythene bags before the spraying of herbicides during the first six months of establishment to reduce injury that could result from the drifting of herbicide solution to plants during their early growth stage. Data was collected on the plant height, stem girth and number of leaves of cocoa plants while the cocoa dry beans weight and labour cost for each treatment were determined. The results showed that 960 g a.i. ha-1 vlv was the best herbicide application rate while plots under glyphosate at 960 g a.i. ha-1 vlv produced significantly higher values of plant height, stem girth and number of leaves at (p=0.05) than both paraquat at 960 g a.i. ha-1 vlv and manual weeding. Labour cost for controlling weeds with either glyphosate or paraquat at all application rates were considerably lower than cost for control (manual weeding). Glyphosate at 960 g a.i. ha-1 vlv is recommended for weed control in cocoa plantation because it encouraged higher growth and yield performance of cocoa than other treatments, had considerably cheaper cost of application than paraquat at 960 g a.i. ha-1 vlv and manual weeding, and it also ensured a weed-free environment over a longer period of time than the other treatments.

Variation in Indonesian cocoa farm productivity in relation to management, environmental and edaphic factors

AbstractA survey was conducted of Indonesian cocoa farms to assess the extent of yield variation and factors associated with this variation. The survey of 120 farms during the course of 3 years encompassed four provinces in Sulawesi (South, South-East, West and Central), Western Sumatra, Lampung, East Java and West Papua. A high degree of yield variation was observed between farms, the average over 3 years ranged from 39 to 3586 kg ha−1. Overall, yields were greater on farms that were classified as ‘highly managed’, compared to ‘moderately’ and ‘less managed’. Seasonal variability in yields was generally greater in districts with a more pronounced dry season such as South Sulawesi and Lampung. Multiple regression analyses revealed particular husbandry practices that were linked with higher cocoa yields. Specifically, the use of inorganic fertilisers, application of fungicides against blackpod and weeding were all practices that were associated with higher yields. A positive association between rainfall and yield was observed for the years 2014/15 and 2015/16 but not 2016/17, which was a La Niña year (when rainfall totals were higher). Some of the farms surveyed were planted with cocoa at very low densities implying an opportunity for yield improvement through gap filling or replanting at higher densities (although it was noted that some farmers maintained lower planting densities due to the cultivation of companion crops). Given the smallholder status of most cocoa farms in Indonesia (mean area in this study was 0.71 ha) it is important that farmers are able to maximise returns from their land in order to maintain a livelihood. This study illustrated the potential for yield improvement on Indonesian cocoa farms through adoption of best agronomic practice.

Hand pollination, not pesticides or fertilizers, increases cocoa yields and farmer income

Increasing demand for cocoa and climate-related yield declines have sparked a multi-stakeholder debate on cocoa production strategies. Agrochemical inputs and pollination enhancement through hand pollination are two strategies to increase yields. Here, we test both strategies with field experiments in Indonesia. We show that even partial hand pollination (13% of easily accessible flowers/tree), and not fertilizers or insecticides, increases yield/tree by 51%. The more laborious 100% hand pollination of the entire tree increases yield/tree by 161%, and farmer’s annual net income from 994 USD/ha up to 1,677 USD/ha, or 69% in the study area, after accounting for farm operational, hand pollination labor, and opportunity costs. Thus, intensifying cocoa pollination appears to be a potential solution for closing cocoa yield gaps and should be considered in the current industry-led discussion of designing farms for mitigation of climate change.

Effect of feather compost on soil chemical indicators in CCN-51 cocoa plantation (Theobroma cacao L.)

Introduction. Organic management of cocoa accounts for 60% of production in Peru and large amounts of compost prepared with different inputs are used, in order to improve the quality of the soil and cocoa yields. Objective. Evaluated the effect of the application of chicken feather compost on the main soil chemical indicators in a cocoa plantation CCN-51 un the Town of Nuevo Progreso, province of Padre Abad in the Ucayali-Peru region was evaluated. Materials and methods. A randomized complete block design was used, with four treatments and four repetitions where: FC1 was an absolute witness, FC2 feather compost at a rate of 2,000 kg. ha-1, FC3 feather compost at a rate of 4,000 kg. ha-1 and FC4 feather compost at a rate of 6 000 kg. ha-1. The main chemical indicators of soil quality were evaluated: hydrogen potential (pH), organic matter (OM), total nitrogen (N), available phosphorus (P), potassium (K+), calcium (Ca2+), magnesium (Mg2+) , aluminum (Al3+), available cadmium (Cd2+), changeable acids (AC) and cation exchange capacity (CEC). Results. The results showed a decrease in exchangeable aluminum and changeable acidity and increases in organic matter, nitrogen, phosphorus, and potassium, depending on the proportion of compost applied, these indicators presented significant differences (p <0.05); The pH, calcium and cadmium available did not show significant differences (p <0.05). Conclusion. Feather compost (FC) significantly improved the levels of OM, N, P and K+, indicators that define soil quality and reduce aluminum levels, the latter of utmost importance in acidic soils.

Impact of Personal Characteristics of Farmers on Cocoa Yields: Case of Centre Region, Mbangassina Municipality, Cameroon

Cameroon is the fifth largest cocoa producer in the world with approximately 220,000 tons of cocoa produced annually. Many factors account for thisproductivity, amongst which are ageing farms and personal characteristics of farmers. The study follows a hypothetico-deductive methodology through whicha random sampling technique was adopted and relevant primary data was gathered with the aid of a structured questionnaire administered to 150 cocoa farmers from5 villages; Talba, Biakoa, Goura II, Mbangassina, and Bilomo. Correlation analysis and ordinary least squares regression were used to examine the relationship andeffects between socio-economic variables and cocoa yields. Findings showed a positive correlation between the socio-economic variables and cocoa yields, socioeconomic factors such as experience in cocoa farming, number of farms, source of labour, farm size, income were statistically significant at p = 1%, 5%, and 10%. Personal characteristics such as farm size, farming experience, percentage of income from cocoa farming, source of labour, number of farms per cocoa farmer,and cocoa price had a significant impact on cocoa yields. However, personal characteristics such as age, sex, marital status and household size did not showany significant impact on cocoa yields. Thus, professionalizing cocoa farmers and training of farmers in good cocoa business practices can go a long way toimprove cocoa productivity.

The role of shade trees in influencing farmers’ adoption of cocoa agroforestry systems: Insight from semi-deciduous rain forest agroecological zone of Ghana

Farmers growing desire for no shade cocoa system has reiterated the scepticism about the impact of research on farmers’ adoption of cocoa Agroforestry. In this study, we assess farmers’ perception about shade trees and how that influences their adoption of cocoa Agroforestry. Five cocoa growing communities in the Eastern Region of Ghana and 91 cocoa farmers were purposively sampled and interviewed. The result showed that the most desirable shade trees among the farmers were Spathodea campanulata, Terminalia superba, and Terminalia ivorensis while Alstonei boonei was the least desirable. About 87 % of farmers introduced shade trees at different stages of cocoa farm establishment while 13 % of farmers had existing trees at establishment. Farmers with less than 11 years farming experience and those with Senior High education kept the recommended number (15–18) of shade trees ha−1. Most farmers related the importance of shade trees to the good growth of cocoa associated crops (37 %) and as source of fodder (31 %), while higher cocoa yield and low education on the importance of shade trees were major reasons farmers removed shade trees. In conclusion, collaboration between farmers and other stakeholders in the cocoa sector is essential in reversing the growing hunger for no shaded cocoa system. This collaboration must focus on educating farmers on the importance of shade trees, and by providing money and agro-inputs support to farmers as impetus for the adoption of cocoa Agroforestry in Ghana.

Physical-chemical indicators of soil and cocoa yield with organic and conventional management

The research evaluated the effect of organic and conventional management on soil physicochemical indicators and performance indicators of CCN-51 cocoa (Theobroma cacao L.). A completely randomized block design was applied, with four treatments: T1 (control), T2 (compost), T3 (NPK) and T4 (compost + NPK) and four repetitions. Physical indicators were evaluated: DA10 and DA20 bulk density and resistance to penetrability RP10 and RP20 (strata from 0.00 to 0.10 m and 0.10 to 0.20 m), chemical indicators: pH, MO, P, K, Ca, Mg, Al and CEC and performance indicators: number of fruits, fruit index and yield per hectare. The results did not show differences in DA and RP in both strata; Differences were found in the indicators pH, MO, P, Al and CEC, T2 and T4 had a greater effect on pH and CEC. Differences were found in the fruit index, in addition, the highest yield per hectare was presented by T2 (1125 kg/ha), although it did not show differences. In conclusion, there were significant chemical changes, except in physical indicators and performance indicators, showing organic production as a viable alternative by not showing differences and exceeding almond yield to chemical treatment.

Application of satellite remote sensing to observe and analyse temporal changes of cocoa plantation in Ondo State, Nigeria

This study examined the changes in the area of land occupied by cocoa plantation in Ondo state in order to provide useful information for effective agricultural policy to increase cocoa yield as the leading export agricultural commodity in Nigeria. Satellite remote sensing technique was employed using satellite imagery of year 2000, 2002, 2014 and 2015 respectively acquired from Landsat-7 ETM+ and Landsat-8 OLI. The land cover of the study area was classified into six classes of cocoa plantation, forest, light forest and grassland, water body, bare surface and rock outcrop as well as settlement area. The result revealed that cocoa plantation occupied 31.3% in 2000, 32.7% in 2002, 41.4% in 2014 and 41.6% in 2015 respectively which depicts gradual increased in the area of land covered by cocoa plantation and its yield at the expense of other land cover classes which prove the potency of this tree crop of generating huge amount of foreign earning for supplementing revenue derived from crude oil in Nigeria. The area of land of other themes changes at different proportions but attention was on the cocoa plantation theme being focus in this research.

Root detection by resistivity imaging and physiological activity with the dead-end trench on three clones of cocoa (Theobroma cacao)

Abstract. Maghfiroh CN, Putra ETS, Dewi HSES. 2020. Root detection by resistivity imaging and physiological activity with the dead-end trench on three clones of cocoa (Theobroma cacao). Biodiversitas 21: 2794-2803. Indonesia is one of the largest cocoa production countries in Southeast Asia, but has low average productivity (982 kg/ha) based on Indonesian Plantation Statistics (2017). Productivity increase effort by giving dead-end trenches that applied to collect organic material, accommodate surface runoff sediments, prevent erosion, and maintain nutrient availability. Dead-end trench had an impact on root cutting and improve rooting. Clone is very influential on cocoa (Theobroma cacao L.) yield. The superior clones recommended are clones RCC-70, RCC-71, and KKM-22, which have high productivity and are resistant to pests and diseases. The objectives of this research were (i) to detect the presence of roots by resistivity imaging (ii) to study the effects of dead-end trench application on physiological activities of cocoa leaves and yields of three clones (RCC-70, RCC-71, and KKM-22); (iii) to determine which cocoa clone (s) performed a significant yield increase with the application of dead-end trench. Research was conducted in August 2018-April 2019 at PT. Pagilaran cocoa plantation in North Segayung Production Unit, subdistrict Tulis, Batang, Central Java. The experiment was arranged in a randomized complete design with two factors and three blocks as replications. The first factor was dead-end trench application (with or without dead-end trench application) and the second factor was cocoa clones (RCC-70, RCC-71, and KKM-22). This study showed that dead-end trench applications affected plant roots based on the interpretation results of geoelectric-resistivity measurements. Dead-end trench application significantly affected chlorophyll a, stomatal conductance, transpiration, and H2O leaf content. Dead-end trench application has no significant effect on the content of chlorophyll b, total chlorophyll content, nitrate reductase activity, stomatal density, CO2 leaf content, and photosynthesis rate.

Comparison Between Machine Learning Models for Yield Forecast in Cocoa Crops in Santander, Colombia

The identification of influencing factors in crop yield (kg·ha-1) provides essential information for decision-making processes related to the prediction and improvement of productivity, which gives farmers the opportunity to increase their income. The current study investigates the application of multiple machine learning algorithms for cocoa yield prediction and influencing factors identification. The Support Vector Machines (SVM) and Ensemble Learning Models (Random Forests, Gradient Boosting) are compared with Least Absolute Shrinkage and Selection Operator (LASSO) regression models. The considered predictors were climate conditions, cocoa variety, fertilization level and sun exposition in an experimental crop located in Rionegro, Santander. Results showed that Gradient Boosting is the best prediction alternative with Coefficient of determination (R2) = 68%, Mean Absolute Error (MAE) = 13.32, and Root Mean Square Error (RMSE) = 20.41. The crop yield variability is explained mainly by the radiation one month before harvest, the accumulated rainfall on the harvest month, and the temperature one month before harvest. Likewise, the crop yields are evaluated based on the kind of sun exposure, and it was found that radiation one month before harvest is the most influential factor in shade-grown plants. On the other hand, rainfall and soil moisture are determining variables in sun-grown plants, which is associated with the water requirements. These results suggest a differentiated management for crops depending on the kind of sun exposure to avoid compromising productivity, since there is no significant difference in the yield of both agricultural managements.

Good Agricultural Practices (GAP 1) Programme and Its Implications on Cocoa Yield of Participants in Ondo State, Nigeria

The continuous fall in the output of cocoa in Nigeria in the past years has been a great concern to the Nigerian Government. Cocoa which is the majorexport crop in Nigeria is experiencing drop in the foreign exchange earnings accruing to the Nigerian Government from its exportation. It is therefore necessary to restore the relevance of cocoa export to the forefront. This necessitated the Federal Government to embark on phase 1 of a programme called Good Agricultural Practices (GAP 1) in which selected cocoa farmers were trained on best sanitation practices that will improve cocoa production. This research determined the effects of farm sanitation training on cocoa output and also determined the relevance of farm sanitation training in cocoa production. Using random sampling procedure; one hundred and ten (110) respondents were selected from the 140 farmers trained on cocoa farm sanitation under the GAP 1 programme of Federal Ministry of Agriculture in partnership with Ondo State Agricultural Development Programme (ODSADP). A well-structured questionnaire was used to gather information from the farmers. Data were analysed using descriptive and inferential statistics such as Chi-square, Pearson Product Moment Correlation and paired T-test. The results revealed that majority (64.5%) of the farmers were male and married (67.3%). The average age of the respondents was 56 years, 18.2% had completed primary school education. The study revealed that cocoa farmers were trained on removal of black pods, cankers, mistletoes, chupons, termites and weeds. The findings also revealed that there was a significant relationship (x2 = 13.220, P = 0.040<0.05) between respondent’s marital status and level of use of farm sanitation training. There was also a significant difference between the cocoa farm output before and after farm sanitation training. There was an increase of cocoa output of the respondents by average of 41.28kg/ha. The use of farm sanitation training was responsible for 7% proportion of the increase in the output of the respondent’s farm. The results of the study further show that there was high level of contact betweenthe cocoa farmers in the study area and the extension agents. Major source of information to the respondents was extension agents of Ondo State ADP. Thefarmers practised the various farm sanitation techniques on which they were trained such as removal of canckers, removal of mistletoes, removal of chupons, hand weeding and picking of unwanted materials. The training variable with the highest impact on the output was removal of pods infected with black pod which brought about 0.290 units change in the output of the cocoa based on the coefficient.

Evaluating the Impact of Rural Finance on Cocoa Farmers Productivity: A Case Study of Bodi District in Ghana

Background: Agricultural finance from rural and community banks play a major role in increasing both yield and income of rural farmers in agricultural-dependent economies. These finances are needed for purchasing raw materials, paying labor fees and buying farming equipment, etc. However, substantial evidence about their roles in improving farm productivity is lacking, especially in the cocoa sector in Ghana, where rural and community banks are the forerunners in advancing credit to cocoa farmers in Ghana’s deprived rural cocoa-growing communities. This research, therefore, seeks to determine the impact of rural and community banks’ credit on cocoa farmers' productivity in the Bodi District of Ghana.
 Methodology: Using random sampling method, a cross-sectional data of 350 cocoa farmers from 5 operational areas (Afere, Bodi, Amoaya, Kama and Suino) located in Bodi District in the Western region. The data were analyzed using descriptive statistics and logistic regression models. Statistical software (SPSS v20 and STATA v14) were used to analyze quantitative data on cocoa productivity.
 Results: The results revealed that cocoa farmers with access to credit experienced significant yield increase (p<0.05) with a mean of 359.71 kgha-1 as compared to 235.30 kgha-1 for non-credit takers. Further, only 34.3% of farmers accessed credit for farming. With Pseudo R2 value of 0.78, farm tenure system, fertilizer use, access to credit and access to extension services significantly influenced cocoa yield, while the age of cocoa farmer, age of farm trees and vulnerability of farm to natural disaster negatively affected cocoa yield. Tukey HSD results (p<0.00) indicate that rural banks credit allocations to non-agricultural activities such as trade and transport, and social loans had the highest percentage means which suggests that agriculture is treated less favorable in rural banks' credit portfolio. These findings give credence to the assertion that rural banks are deviating from their core mandate of supporting agriculture in Ghana.
 Conclusion: This study reaffirms the supporting roles played by rural and community banks in increasing cocoa yield in Ghana. However, this research recommends that, the Bank of Ghana should closely monitor the activities of these unit banks to reduce the instances of diverting all their funds to non-agricultural related activities.

Strategy for improving sustainable cocoa (Theobroma cacao L) plant productivity in South Sulawesi based on land suitability

This study aimed to establish land suitability classes in South Sulawesi for cocoa plant development, determine the productivity potential of South Sulawesi cocoa, and determine efforts to optimize cocoa productivity in South Sulawesi. The method used was a mixed qualitative and quantitative. The study was conducted in three cocoa producing districts with different climate types. 18 units of soil profiles were analyzed and interviews with farmers was carried out to obtain information on the actual cocoa yield and implemented management. Land suitability analysis was conducted using a parametric approach (square root method), farming analysis (B/C ratio), Analytical Hierarchy Process (AHP) for decision making, and correlation analysis to determine the relationship of suitability index with cocoa yield. The results show that the climate suitability analysis at the location was S3 (marginally suitable) and S2 (moderately suitable). The results of land suitability in Bantaeng Regency are mostly S3 (marginally suitable) with limiting factors for soil depth and humidity. Whereas in the districts of East Luwu and Pinrang, land suitability classes obtained were S3 (marginally suitable) and S2 class (moderately suitable). The limiting factors included climate (rainfall and humidity), soil depth, pH and slope. Overall cocoa farming in South Sulawesi is feasible to be developed with an R/C value> 1, NPV of IDR13,495,268; Net B/C 1.1, and IRR of 15.8%. Correlation analysis between land suitability index and cocoa productivity was not statistically significant (P <0.05). The priority strategy for increasing cocoa crop productivity is the addition of organic fertilizer.

The effectiveness of the land suitability analysis approach as a determinant of a sustainable cocoa (Theobroma cacao. L) productivity improvement strategy in East Luwu Regency

This study was conducted at Burau, Wotu, and Mangkutana Districts which are the center of cocoa production in East Luwu Regency. This study aimed to determine the strategies to increase cocoa yields (Theobroma cacao. L) in East Luwu according to the land suitability assessment and SWOT analysis. In this study, firstly, primary and secondary data were collected by doing a survey, while the determination of study sites was based on purposive sampling tecnique. Following data collection, land suitability assessment and SWOT analysis were conducted and used in order to determine the strategies. The results show that Burau, Wotu, and Mangkutana Districts are categorized in class S2 land (moderately suitable). In Burau, the limiting factor is temperature, while in Wotu and Mangkutana, the constrains are temperature, rainfall, and soil texture. Based on SWOT analysis and land suitability assessment, the strategies to increase cocoa productivity are optimizing the inputs of organic fertilizer and pesticide, using superior cultivars, educating the local farmers by organizing a weekly meeting, improving the production cost of cocoa beans, using cover crops, making catchment area, and improving the technologies.

IMPACT OF A GROWTH ENHANCEMENT SUPPORT SCHEME ON COCOA YIELD AND INCOME OF COCOA FARMERS IN OSUN STATE, NIGERIA

Background. In an attempt to improve the yield of cocoa and farmers income, the Federal government of Nigeria in 2012 introduced the Cocoa Growth Enhancement Support (GES) scheme that subsidized farm inputs to farmers. This article examines the effects of the scheme on cocoa yield and the income of cocoa farmers in Osun State.Material and methods. A multistage sampling procedure was used to obtain data from 208 cocoa farmers of whom there were 100 participants and 108 non-participants of the scheme. Data collected were analyzed using descriptive statistics, the binary logit regression model and the Propensity Score Matching (PSM) model.Results. Descriptive statistics revealed no mean difference between some socioeconomic characteristics among the categories of farmers in the study area such as household size, farming experience, age and education. The results further revealed that participation in previous government intervention programs, access to extension services and access to credit were significant determinants of participation in the GES scheme. Participation in the GES scheme increased cocoa yield and income of cocoa farmers by 42.30 kg·ha-1 and 24553.99 N·ha-1 (59.71 €·ha-1), respectively.Conclusion. This suggests that a subsidy on farm inputs could increase cocoa yield and the income of cocoa farmers.

Integrated Soil Fertility Management for Small Holder Cocoa Farms: Using Combination of Cocoa Pod Husk Based Compost and Mineral Fertilizers

Nutrients are being removed through pod harvest without replacement in the form of fertilizer application leaving the soil impoverished and the nutrients grossly inadequate for optimum cocoa yield. To address this issue, a randomised complete block designed study was carried out to examine the effects of readily available source of organic fertilizer like cocoa pod husks compost combined with mineral fertilizers on the yield of cocoa. The treatments with three replications consisted of Compost (100%), Compost (75%) + NPK (25%), Compost (50%) + NPK (50%), NPK (100%) and Control (no fertilizer). Results indicated that cocoa yield obtained with the compost plus NPK fertilization was significantly higher than with sole compost, NPK applications, and control in all locations. Percentage dry cocoa bean yield gain was 72.4% with the compost plus NPK fertilization, while sole compost or NPK alone was 36.4% compared to the control. Additionally, compost plus NPK fertilization significantly reduced black pod losses compared to sole compost, NPK, or control with percentage loss rate ranging from 9.9 to 13.4%, 21.6 to 23.1, 19.6 to 22.3, 32.2 to 35.5, respectively, in all locations. The use of CPH-based compost plus NPK fertilization has the potential to provide efficient integrated soil fertility restoration scheme that incorporated good agricultural practices and addressed disease management.

Impact of insecticide and pollinator-enhancing substrate applications on cocoa (Theobroma cacao) cherelle and pod production in Côte d’Ivoire

Cocoa yield in the major cocoa-producing countries is far below potential levels. It has been shown that apart from poor soil fertility, inadequate genotypes and pest and disease incidence, this yield gap is caused by below-optimum pollination levels. On 3 Ivorian cocoa farms, during the six months preceding the main harvest season of 2018–2019 (August 2018 until January 2019), we used generalized mixed models to investigate how the creation of a pollinator-friendly environment by applying rotting organic material (banana pseudostems) to cocoa fields, combined with and without insecticide applications, influences cocoa production. It was found that banana pseudostem treatments had a positive effect on cherelle production but that this effect was only observed in plots treated with insecticide to protect cherelles against sap-sucking mirids, at the beginning of the experiment. Furthermore, although we did not find significant differences in cherelle wilt rates between treated and control plots, we did not observe a significantly higher accumulated number of mature pods that were produced on trees treated with substrate and untreated control trees during the 25 week experimental period. The pollination-enhancing effect of the substrate on cherelle production in sprayed plots was significantly higher in trees that were close (<1 m) to the holes to which the substrate was applied, compared to trees that were further away from these holes. Reduced rainfall towards the end of the minor rainy season of October – November, concurred with a decrease in the number of flowers but also with a decrease in fruit set rate. Soils of all experimental farms had nutrient levels considered to be inadequate for cocoa production, which can explain why the increase in cherelles (+ 75 % and + 50 % in trees respectively close to and further away from substrate holes) did not result in significant increases in mature pods. Our results suggest that closing the pollination gap will close the cocoa yield gap, only when other factors that prevent cherelles to develop into mature pods, are addressed.

Cocoa agroforest multifunctionality and soil fertility explained by shade tree litter traits

Abstract Manipulating plant functional diversity to improve agroecosystem multifunctionality is a central challenge of agricultural systems world‐wide. In cocoa agroforestry systems (cAFS), shade trees are used to supply many services to farmers, yet their impact on soil functioning and cocoa yields is likely to vary substantially among tree species. Here we compared the impact of five shade tree species (Canarium schweinfurthii (Canarium), Dacryodes edulis (Safou), Milicia excelsa (Iroko), Ceiba pentandra (Kapok tree), Albizia adianthifolia (Albizia)) and unshaded conditions on the functioning of poor sandy savanna soils within eight cocoa farms in Central Cameroon. We assessed the effects of plant functional traits, leaf litterfall and fine root biomass on a range of soil functions and on cocoa yield. Shade trees generally improved soil pH, , and Olsen P content, biomass production of bioassays and soil total C and N content, while leaving cocoa yields unchanged. However, these effects varied largely among species. Improvements of soil functions were low under the two fruit trees (Canarium and Dacryodes), medium under the legume tree Albizia and high under the two timber trees (Milicia and Ceiba). Low litter recalcitrance was most strongly associated with increases in soil fertility indicators such as N and P availability, whereas soil C and N content increased with litter Ca restitution. Synthesis and applications. We demonstrate that cocoa agroforest multifunctionality is substantially influenced by the functional traits of shade tree species. Shade tree species with the most dissimilar traits to cocoa (cocoa showing the lowest leaf litter quality) showed the largest improvement of soil functions. Therefore, selection of shade trees based on their functional traits appears as a promising practice to adequately manage soil functioning. In order to fully assess the beneficial role of shade trees in these agroecosystems. Future research will need to extend this approach to other below‐ground traits and other aspects of multifunctionality such as long‐term cocoa health and yield.