Open Access Short Research Article

Response of Forty (40) High-Producing Cacao Genotypes to Cacao Swollen Shoot Disease

Caudou I. Trebissou, Roméo K. N’Guessan, Mathias G. Tahi, Sékou Aïdara, Sélastique D. Akaffou, Simon-Pierre A. N’Guetta

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/jeai/2020/v42i1030608

Aims: Cocoa swollen shoot is a dreaded viral disease that is prevalent in the producing areas of West Africa. In Côte d'Ivoire, it undermines the sustainability of cocoa farming. Integrated pest management based on the use of disease-resistant or disease-tolerant plant material remains a sustainable solution.

Place and Duration of Study: Integrated Pest Management Unit against Cocoa swollen shoot, Experimental greenhouse of Bouaflé, National Centre for Agronomic Research (CNRA).

Methodology: Forty elite genotypes of cocoa trees selected from different populations in the Reciprocal Recurrent Selection program of Cocoa in Côte d'Ivoire were evaluated against strain D of Cacao Swollen Shoot Virus (CSSV). Five seedlings of each genotype were infected by patch grafting and observed for 5 months.

Study Design: Plants are placed in a greenhouse in a completely random arrangement, with five repetitions.

Results: Three cocoa genotypes (C77, C87 and C96) were free of disease symptoms and eight genotypes (C77, C87, C96, C3, C12, C26, C53 and C98) had the lowest infection scores. The disease significantly affected plant development and growth.

Conclusion: Some genotypes selected within the Reciprocal Recurrent Selection program are promising for breeding against CSSV disease. These eight genotypes will be tested in a field environment to confirm their tolerance.

Open Access Original Research Article

Plant Growth Regulators in Flowering Alternation of the Fuji Suprema Apple Tree

José Luiz Petri, André Amarildo Sezerino, Cristhian Leonardo Fenili

Journal of Experimental Agriculture International, Page 11-18
DOI: 10.9734/jeai/2020/v42i1030609

Aims: Research on alternate bearing in apple trees is usually focused on chemical                thinning techniques, but in recent decades synthetic bioregulators have proven to be             effective in promoting or inhibiting floral induction in apple trees. However, the results can be variable since some cultivars are prone to alternation, as Fuji and its clones. The objective of the present study was to observe the effect of naphthalene acetic acid (NAA), Ethephon,                   and their combinations in the formation of flowering buds avoiding flowering alternation, in Cv, Fuji Suprema.

Place and Duration of Study: The experiments were carried out in southern Brazil, municipality of Caçador / SC, during the cycles from 2014 to 2019, in the cultivar Fuji Suprema / Marubakaido / M9, with 12 years old.

Methodology: Several variables were evaluated such as flowering return, fruit set, yield, number of fruits per plant, average fresh fruit mass, and biennial bearing index (BBI).

Results: The results were variable and showed that NAA and Ethephon had little effect on reducing flowering alternation when applied during the vegetative phase of the Fuji Suprema apple tree. After years of high productivity, there was a decrease in the yield, even in the treatments of NAA and Ethephon. Ethephon or its combination with NAA has a thinning effect, but without influence on the return of flowering.

Open Access Original Research Article

Assessment of Awareness and Utilization of Cocoa Production Technologies among Farmers in Oyo State, Nigeria

D. J. Awodumila, T. E. Ogunjobi, A. O. Orimogunje, B. A. Ogundeji, E. E. O. Agbebaku, R. T. Olorunmota, G. A. Adewoye

Journal of Experimental Agriculture International, Page 19-25
DOI: 10.9734/jeai/2020/v42i1030610

The study examined farmers’ awareness and utilization of cocoa production technologies in Oyo State, Nigeria. Specifically, the study described the socio economic characteristics of the respondents, ascertained the levels of awareness and utilization of cocoa production technologies and identified the sources of information on cocoa production technologies by farmers. Multi stage random sampling was used to select one hundred and twenty (120) cocoa farmers. Data was collected using a comprehensive questionnaire and analysis was done using means, frequencies percentages, Chi square and Pearson Product Moment correlation (PPMC). The results revealed that 62.4% of the respondents were within age bracket (<30-50) years, male 83.3%, married 76.6%, mean house hold size 7.5 and mean farm size 4.1ha. There was relatively high awareness (60.8%) of cocoa production technologies among respondents. Also, there was high utilization of site selection/land preparation, control of pest insect and pathogens, regular weeding and timely harvesting /processing (x= 1.0), use of improved cocoa varieties, shade management and regular pruning (x=0.9). However, there was low utilization of gapping up of missing/death stands and planting period and spacing(x=0.7), cocoa rehabilitation (x=0.5) and appropriate fertilizer application with a means of 0.6. About 60% of the respondents accessed information from cocoa Research Institute of Nigeria (CRIN). Chi-square analysis showed that there was significant relationship (p, < 0.005) between age (x=19.233) and utilization of cocoa production technologies. However, the significant relationship was not found between sex (x=0.754), marital status (x=3.359), religion (x=1.416), level of education (x=2.254) and utilization of cocoa production technologies. PPMC analysis (r=0.633) revealed that there was positive significant relationship between awareness and utilization of cocoa production technologies by respondents. Farmers need to be trained on various cocoa rehabilitation methods and improved cocoa varieties should be made available at affordable price to farmers.

Open Access Original Research Article

Determinants and Policy Ramifications of Cocoa Farmers’ Use of Agrochemicals in Cocoa-Based (Theobroma cacao) Agroforestry Systems in Cameroon

Azembouh Roshinus Tsufac, Nyong Princely Awazi, Bernard Palmer Kfuban Yerima

Journal of Experimental Agriculture International, Page 26-37
DOI: 10.9734/jeai/2020/v42i1030611

The application of agrochemicals in agroforestry systems in general and cocoa-based agroforestry systems in particular is unprecedented as agroforestry systems are considered as environmentally benign, agro-ecological and sustainable agricultural systems. It was within this context that this study was undertaken to examine the determinants of cocoa farmers’ use of agrochemical in cocoa-based agroforestry systems. Through a mixed research approach, and data analysis using appropriate descriptive and inferential statistical tools, it was found that the main types of herbicides used by cocoa farmers in cocoa-based agroforestry systems are Paraquat (50%) and Glyphosate (40%). For fungicides, the main types used were Mancozeb (70%), Maneb (65%), Ridomil (60%), Caocobre (50%), and Nordox (40%). For insecticides, the main types used were Methyl (65%), Imidacloprid (60%), Endosulfan (50%), Cypermethrin (50%), and Fenobucarp (40%). The most common pests and diseases affecting cocoa perceived by cocoa farmers in cocoa-based agroforestry systems were Black pod – Phytophtora spp (100%), Capsid/Mirids – Distantiella theobroma and Sahlbergella singularis (100%), Cocoa Swollen Shoot Virus Disease – CSSVD (60%), Witches’ broom – Crinipellis perniciosa (50%) and Vascular streak dieback (40%). Most cocoa farmers perceived that the use of all three agrochemicals (herbicides, fungicides, and insecticides) in cocoa-based agroforestry systems have negative socio-economic and environmental impacts.  From Spearman rank correlation and logistic regression coefficients, it was noticed that the main explanatory variables having a statistically significant direct non-cause-effect and cause-effect relationship (p<0.05) with cocoa farmers’ use of agrochemicals in cocoa-based agroforestry systems were gender, income, availability of agrochemicals, access to information, membership in farming groups, and access to extension services. Meanwhile the main explanatory variables having a statistically significant indirect or inverse non-cause-effect and cause-effect relationship (p<0.05) with cocoa farmers’ use of agrochemicals in cocoa-based agroforestry systems were farm size and number of farms. It is recommended that policy makers take a critical look at the different agrochemicals used by cocoa farmers as well as the determinants of their use when formulating policies geared towards ensuring the sustainable use of these agrochemicals in cocoa-based agroforestry systems.

Open Access Original Research Article

Application of Chemical Fertilizers in Cocoa-Based (Theobroma cacao) Agroforestry Systems; Impact on Yields and Policy Ramifications: Empirical Evidence from Cameroon

Azembouh Roshinus Tsufac, Bernard Palmer Kfuban Yerima, Nyong Princely Awazi, Roger Kogge Enang

Journal of Experimental Agriculture International, Page 38-49
DOI: 10.9734/jeai/2020/v42i1030612

Soil fertility decline has pushed farmers across the world to resort to chemical fertilizers in order to improve soil fertility and enhance crop yields. In agroforestry systems, the application of chemical fertilizers is a call for concern considering that agroforestry systems are supposedly agro-ecological, environmentally friendly and sustainable systems. It was within this context that this study sought to assess the application of chemical fertilizers in cocoa-based agroforestry systems and its policy ramifications. Data was collected through a household survey of 300 cocoa farmers in Cameroon, and analyzed on SPSS 17.0 employing descriptive and analytical techniques. It was found that the most commonly used chemical fertilizers by cocoa farmers in cocoa-based agroforestry systems were NPK 20:10:10 (60%), NPK 15:20:15 (50%), and Urea (40%). It was also noticed that a majority of the cocoa farmers sampled used no chemical fertilizer (35%), very small quantity (15%), small quantity (20%), and moderate quantity (20%). With respect to frequency of use, most cocoa farmers never used chemical fertilizer (35%), used it rarely (30%), or used it occasionally (15%). However, some cocoa farmers used chemical fertilizers frequently (5%) and very frequently (5%) in their cocoa agroforests. Coefficients of correlation and regression showed the existence of a statistically significant (p<0.05) direct and inverse non-causal and causal relationship between different explanatory variables (income level, availability of chemical fertilizers, access to information, membership in farming group and access to extension services) and cocoa farmers’ use of chemical fertilizers; while farm size and number of farms had a statistically significant inverse relationship. Correlation and regression coefficients showed the existence of a statistically significant (p<0.05) direct non-causal and causal relationship between different levels of cocoa yields (very high cocoa yield, high cocoa yield, average cocoa yield, low cocoa yield, very low cocoa yield, no change in cocoa yields) and the application of chemical fertilizers in cocoa-based agroforestry systems. On the basis of the study’s findings, it is recommended that measures be taken to limit the use of chemical fertilizers in cocoa-based agroforestry systems in order to enhance the sustainability of these systems.

Open Access Original Research Article

Cocoa Farmers’ Perceptions of the Contribution of Tree Diversity and Abundance to Soil Fertility in Cocoa-Based (Theobroma cacao) Agroforestry Systems in the Littoral Region of Cameroon

Azembouh Roshinus Tsufac, Bernard Palmer Kfuban Yerima, Nyong Princely Awazi, Roger Kogge Enang

Journal of Experimental Agriculture International, Page 50-59
DOI: 10.9734/jeai/2020/v42i1030613

Tree diversity and abundance within an agroforestry system plays a crucial role in the provision of different ecosystem services. It was within this framework that this study sought to examine the contribution of tree diversity and abundance to soil fertility in cocoa-based agroforestry systems. A mixed research approach was adopted during data collection and data analysis was done through the use of descriptive and inferential statistical tools. From the findings of the study, it was revealed that most cocoa farmers perceive tree diversity in cocoa-based agroforestry systems to be between average (50%), high (15%) and very high (20%), while tree abundance was between average (40%), and low (30%). The main types of tree species integrated by cocoa farmers in cocoa-based agroforestry systems were fruit trees (100%), fuelwood trees (70%), trees for shade (52.7%) and trees for building materials (40%). A statistically significant direct relationship (p<0.05) existed between different levels of tree diversity (very high tree diversity, high tree diversity, average tree diversity, low tree diversity, and very low tree diversity) and soil fertility in cocoa-based agroforestry systems, implying that the greater the diversity of tree species the greater the levels of soil fertility in cocoa-based agroforestry systems. Different levels of tree abundance in cocoa agroforests such as average tree abundance, low tree abundance and very low tree abundance had a statistically significant direct relationship (p<0.05) with soil fertility in cocoa-based agroforestry systems, implying that the lower the level of tree abundance, the greater the level of soil fertility in cocoa-based agroforestry systems. Meanwhile levels of tree abundance in cocoa agroforests such as very high tree abundance and high tree abundance had a statistically significant inverse relationship (p<0.05) with soil fertility in cocoa-based agroforestry systems, implying that the higher the tree abundance, the lesser the level of soil fertility. Thus, it is recommended that more diverse tree species should be integrated in cocoa-based agroforestry systems while tree abundance should be kept to an average level in order to sustain the level of soil fertility in cocoa-based agroforestry systems.

Open Access Original Research Article

Diversity in Qualitative and Quantitative Traits Reveals Huge Potential for the Improvement of an Orphan Crop Tef [Eragrostis tef (Zucc.) Trotter]

Habte Jifar, Kebebew Assefa, Kassahun Tesfaye, Kifle Dagne, Zerihun Tadele

Journal of Experimental Agriculture International, Page 60-75
DOI: 10.9734/jeai/2020/v42i1030614

Aims: To assess the extent and pattern of genetic diversity in major qualitative and quantitative traits of tef accessions based on collection altitudes, and administrative regions and zones.

Study Design: Randomized complete Block Design with three replications.

Place and Duration of Study: The study was conducted at Debre Zeit and Holetta Research Centers in 2015 main cropping season.

Methodology: One hundred forty-four tef accessions collected from the Northern and Central Ethiopia were evaluated using five qualitative and seven quantitative traits. Microsoft Excel and Shannon-Weaver diversity index were used to determine the extent of genetic variations while cluster analysis based on the standardized data of various qualitative and quantitative traits was employed to group the accessions and collection altitudes, zones and regions.

Results: Yellowish white lemma, loose panicle, white seed, four internodes and green basal stalk were found to be the predominant phenotypic classes of the studied qualitative traits. The highest mean Shannon diversity was observed for panicle forms (0.396) followed by seed colour (0.370) while the lowest value was for basal stalk colour (0.083). Accessions from Oromia Regional State had the highest mean Shannon diversity and grain yield compared to the other two Regional States. Similarly, accessions from South Wello and West Shewa administrative zones had the highest mean Shannon diversity and highest grain yield, respectively. Besides, accessions from altitudes below 1500 m above sea level (a. s. l.) and from 2001 to 2500 m a. s. l. also had the highest mean diversity and highest mean grain yield, respectively. In cluster analysis, dendrogram constructed based on five qualitative and seven quantitative traits grouped the accessions, collection regions, zones and altitudes into six, two, four and three distinct clusters, respectively.

Conclusion: The present study generally revealed huge diversity among tef accessions collected from different regional states, administrative zones and altitudes which can be harnessed in future improvement of this understudied crop.

Open Access Review Article

Influence of the Soil Preparation Method on the Aerial and Root Development of the Clone GT 1 of Hevea brasiliensis, Mull. Arg (Euphorbiaceae) in the South-West of Cote D’ivoire

Konan Djézou, Ballo Espérence Kouadio, T. Vawa Otro Serge, P. Kouakou Yao Alban, Obouayeba Samuel, Dea Goué Bernard

Journal of Experimental Agriculture International, Page 76-84
DOI: 10.9734/jeai/2020/v42i1030615

Objective: The study was carried out on the plots of the Southwest Agricultural Civil Society (SCASO) in southwestern Côte d'Ivoire. the objective of this study is to evaluate the aerial and root development of rubber plants of Gondang Tapen 1 (GT 1) clone, through the method of land preparation

Methodology and Results: The methodology focused on plougheds soils of the experimental plots according to a toposequence (summit, mid-slope and low-slope). This treatment was compared with control plots on unploughed soil. The results obtained showed that ploughed soil favoured good aerial development of plants of the GT 1 clone, especially in the lower slopes of plots installed on a toposequence gradient. This cultivation technique also allows a good elongation of the main root of the rubber plants of the GT 1 clone, mainly at the summit and bottom of the toposequence, thus ensuring good fixation in the soil, and thus resistance to windthrow and water supply in the dry season. The study indicated a close relationship between the development of the aerial and underground parts of the GT 1 clone plants on undisturbed (unploughed soil) soils.

Conclusion and Application: Evaluation of the influence of the mode of land preparation on the aerial and root development of the GT 1 a clone showed that mechanical soil preparation by ploughed soil in rubber cultivation is an appropriate cultivation technique to boost the development of rubber trees in plantations, when soil characteristics require it.