African Journal of Agriculture

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 154–161

DOI: 10.46882/2026/AJA/000753

Article Type: Original Research Article

Title: Technical Efficiency and Profitability of Cage Aquaculture Systems among Fish Farmers around Lake Victoria, Kenya

Names of Authors: Kevin O. Onyango¹, Beatrice A. Omondi¹, Collins P. Odhiambo²

Authors’ Affiliations: ¹Kenya Marine and Fisheries Research Institute (KMFRI), Kisumu Station, Kisumu, Kenya; ²Department of Agricultural Economics, Maseno University, Maseno, Kenya

Abstract: Overfishing and wild stock depletion in Lake Victoria have driven a rapid expansion of commercial cage aquaculture. However, high operational input costs, especially for commercial feeds, threaten the financial sustainability of these small- and medium-scale ventures. This study applied a stochastic frontier production function model to analyze the technical efficiency and net profitability of 150 tilapia (Oreochromis niloticus) cage aquaculture enterprises operating in Kenyan waters. Primary data were gathered through production logs and face-to-face interviews covering structural dimensions, feed budgets, stocking density, and harvest values. Cost-benefit metrics indicated that cage aquaculture remains profitable, yielding an average net return of US$ 1,240 per production cycle per cage. The stochastic frontier analysis revealed a mean technical efficiency of 74.2%, showing that operators could boost outputs by 25.8% using their current resource base. Fingerling quality and feed volume were positive, statistically significant factors driving output (p < 0.05). Inefficiency modeling showed that lack of technical training, informal cooperative setups, and poor water quality management increased technical errors. The study recommends public investment in local hatcheries to lower fingerling costs and standardizing extension training to improve feed conversion efficiencies.

Keywords: Cage aquaculture, Oreochromis niloticus, Stochastic frontier, Technical efficiency, Feed conversion, Aquaculture economics

Manuscript Timeline: Received: June 15, 2026; Revised: July 18, 2026; Accepted: August 09, 2026; Published: August 31, 2026

Citation: Onyango, K. O., Omondi, B. A., & Odhiambo, C. P. (2026). Technical Efficiency and Profitability of Cage Aquaculture Systems among Fish Farmers around Lake Victoria, Kenya. African Journal of Agriculture, 13(8), 154–161. DOI: 10.46882/2026/AJA/000753

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 146–153

DOI: 10.46882/2026/AJA/000752

Article Type: Original Research Article

Title: Efficacy of Metarhizium anisopliae and Spinetoram against Fall Armyworm (Spodoptera frugiperda) on Maize in Southern Benin

Names of Authors: Sègbégnon G. Agbovi¹, Cossi J. Tossou¹, Albert O. Gbaguidi²

Authors’ Affiliations: ¹Institut National des Recherches Agricoles du Bénin (INRAB), Cotonou, Benin; ²Université d'Abomey-Calavi, Faculté des Sciences Agronomiques, Cotonou, Benin

Abstract: The invasive fall armyworm (Spodoptera frugiperda J.E. Smith) causes continuous defoliation damage in West African maize fields. Heavy reliance on broad-spectrum synthetic chemical pesticides creates pesticide resistance risks and endangers beneficial field organisms. This study evaluated the comparative field efficacy of the entomopathogenic fungus Metarhizium anisopliae (strain ICIPE 7) and the bio-insecticide Spinetoram, individually and in rotation, against S. frugiperda larvae. Field trials used a randomized block setup with four replicates per treatment. Treatments included: M. anisopliae alone (2.0 x 10¹² spores/ha), Spinetoram alone (250 mL/ha), an alternating rotation of M. anisopliae and Spinetoram, and an untreated control. Larval populations and leaf damage scores were recorded at 3, 7, and 14 days post-application. The results revealed that Spinetoram alone achieved the fastest knockdown effect, cutting larval counts by 88.5% within 3 days. However, the alternating rotation treatment (M. anisopliae followed by Spinetoram) provided the most durable protection, keeping leaf leaf damage below 12.0% across the whorl development stage. This rotational treatment limited final grain yield loss to just 4.2% compared to a 38.6% yield collapse in the untreated control plots. Integrating M. anisopliae with targeted Spinetoram applications offers a highly effective strategy to control fall armyworm while mitigating chemical resistance risks.

Keywords: Spodoptera frugiperda, Metarhizium anisopliae, Spinetoram, Larval mortality, Integrated pest management, Yield protection

Manuscript Timeline: Received: June 11, 2026; Revised: July 15, 2026; Accepted: August 06, 2026; Published: August 31, 2026

Citation: Agbovi, S. G., Tossou, C. J., & Gbaguidi, A. O. (2026). Efficacy of Metarhizium anisopliae and Spinetoram against Fall Armyworm (Spodoptera frugiperda) on Maize in Southern Benin. African Journal of Agriculture, 13(8), 146–153. DOI: 10.46882/2026/AJA/000752

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 138–145

DOI: 10.46882/2026/AJA/000751

Article Type: Original Research Article

Title: Genetic Variability, Heritability, and Selection Indices for Root Yield Components in Sweet Potato (Ipomoea batatas L.) Germplasm of Southern Malawi

Names of Authors: Memory F. Banda¹, Blessings K. Phiri¹, Charles L. Maliro²

Authors’ Affiliations: ¹Department of Horticulture, Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi; ²Bunda College of Agriculture, Crop Sciences Department, Lilongwe, Malawi

Abstract: Breeding high-yielding, beta-carotene-rich sweet potato (Ipomoea batatas L.) requires a precise understanding of genetic variability and genetic advance for targeted root parameters. This study evaluated the genetic components, broad-sense heritability (H²), and selection gains for yield-related traits across 24 sweet potato genotypes under rainfed conditions in southern Malawi. The experiments used a randomized complete block layout with three replications. Morphological markers, including storage root count per plant, average root weight, dry matter content, and total storage root yield, were monitored. Statistical analyses revealed significant variation across all genotypes for all measured traits (p < 0.01). The genotypic coefficient of variation (GCV) for total storage root yield (28.4%) was close to the phenotypic coefficient of variation (32.1%), showing a strong genetic foundation and low environmental interference. Broad-sense heritability estimates were exceptionally high for storage root yield (84.5%) and average root weight (78.2%). Crucially, total storage root yield displayed a high genetic advance as a percentage of the mean (54.2%), indicating that selective breeding can yield substantial improvements. Genotype LUST-26 logged the highest mean storage root yield at 22.45 ± 1.12 t/ha along with an acceptable root dry matter content of 31.4%. Selecting parental lines based on root count and individual root weight will maximize genetic gains in sweet potato improvement programs.

Keywords: Ipomoea batatas, Genotypic coefficient, Heritability, Genetic advance, Root yield, Breeding selection

Manuscript Timeline: Received: June 08, 2026; Revised: July 12, 2026; Accepted: August 04, 2026; Published: August 31, 2026

Citation: Banda, M. F., Phiri, B. K., & Maliro, C. L. (2026). Genetic Variability, Heritability, and Selection Indices for Root Yield Components in Sweet Potato (Ipomoea batatas L.) Germplasm of Southern Malawi. African Journal of Agriculture, 13(8), 138–145. DOI: 10.46882/2026/AJA/000751

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 130–137

DOI: 10.46882/2026/AJA/000750

Article Type: Original Research Article

Title: Integration of Pigeonpea (Cajanus cajan L.) Cover Cropping into Sorghum Systems for Weed Suppression and Nitrogen Conservation in Central Tanzania

Names of Authors: Neema S. Mrema¹, Rashid A. Suleiman¹

Authors’ Affiliations: ¹Tanzania Agricultural Research Institute (TARI), Ilonga Centre, Kilosa, Tanzania

Abstract: Smallholder sorghum farmers in semi-arid central Tanzania struggle with aggressive weed infestations and low soil nitrogen levels, both of which severely depress cereal yields. Integrating leguminous cover crops like pigeonpea (Cajanus cajan L.) into sorghum (Sorghum bicolor L.) fields could offer an eco-friendly path to suppress weeds and fix nitrogen. This 3-year field study explored the agronomic benefits of three distinct intercropping patterns: T1 (Sole Sorghum), T2 (Sorghum + Pigeonpea intra-row intercrop), T3 (Sorghum + Pigeonpea 1:1 row arrangement), and T4 (Sorghum + Pigeonpea 2:1 row arrangement). Weed density, weed biomass, soil mineral nitrogen (N), and final crop yields were measured. The 1:1 row layout (T3) achieved the best results, cutting weed biomass by 62.4% at 45 days post-planting compared to the sole sorghum control (p < 0.05). Soil testing showed that the T3 pattern added an average of 42.6 kg N/ha into the soil root zone through biological nitrogen fixation and litter decay. Although intercropping led to a minor reduction in individual sorghum grain yield (3.12 t/ha in T3 vs 3.45 t/ha in T1), it generated an exceptional pigeonpea grain yield of 1.24 t/ha. This elevated the total system Land Equivalent Ratio to 1.38, confirming high land-use efficiency and economic returns.

Keywords: Sorghum bicolor, Cajanus cajan, Intercropping, Weed suppression, Land equivalent ratio, Sustainable farming

Manuscript Timeline: Received: June 04, 2026; Revised: July 10, 2026; Accepted: August 02, 2026; Published: August 31, 2026

Citation: Mrema, N. S., & Suleiman, R. A. (2026). Integration of Pigeonpea (Cajanus cajan L.) Cover Cropping into Sorghum Systems for Weed Suppression and Nitrogen Conservation in Central Tanzania. African Journal of Agriculture, 13(8), 130–137. DOI: 10.46882/2026/AJA/000750

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 122–129

DOI: 10.46882/2026/AJA/000749

Article Type: Original Research Article

Title: Agronomic Performance and Bio-Oil Yield of Interspecific Oil Palm (Elaeis guineensis x Elaeis oleifera) Hybrids in Southwest Cameroon

Names of Authors: Daniel M. Ewane¹, Fidelis N. Tanyi¹, Theresa B. Njoume²

Authors’ Affiliations: ¹Institute of Agricultural Research for Development (IRAD), Ekona Regional Centre, Buea, Cameroon; ²Department of Agronomy, University of Dschang, Dschang, Cameroon

Abstract: Traditional Elaeis guineensis oil palm plantations face severe losses from fatal yellowing disease and bud rot across Central Africa. Interspecific hybrids (Elaeis guineensis x Elaeis oleifera, or OxG) offer a strong genetic defense against these biotic stresses, but their long-term agronomic yields require localized verification. This study tracked the vegetative growth, bunch component analysis, and crude palm oil (CPO) productivity of three elite OxG hybrid crosses (Coari x La Mé, Taisha x Ekona, and Manicoré x Pobe) over an 8-year production lifecycle in southwest Cameroon. The field trial was set up using a randomized complete block design with four replicates. The Taisha x Ekona hybrid displayed high tolerance to bud rot, with a recorded incidence of 0.0% compared to 14.5% in the local E. guineensis check. Hybrid Taisha x Ekona also achieved the highest fresh fruit bunch yield, averaging 22.4 ± 1.5 t/ha/year at maturity. Bunch analysis revealed an extraction rate of 21.8% CPO for Taisha x Ekona, equating to a net oil yield of 4.88 t/ha/year. The oil characterization showed a high iodine value (64.2 g I/100g) and an unsaturated oleic acid fraction exceeding 54.0%, indicating premium oil quality. This research confirms that the Taisha x Ekona hybrid provides high oil output and excellent disease resistance for Central African growers.

Keywords: Elaeis guineensis, Interspecific hybrids, Bud rot resistance, Fresh fruit bunch, Crude palm oil, Cameroon

Manuscript Timeline: Received: June 01, 2026; Revised: July 05, 2026; Accepted: July 30, 2026; Published: August 31, 2026

Citation: Ewane, D. M., Tanyi, F. N., & Njoume, T. B. (2026). Agronomic Performance and Bio-Oil Yield of Interspecific Oil Palm (Elaeis guineensis x Elaeis oleifera) Hybrids in Southwest Cameroon. African Journal of Agriculture, 13(8), 122–129. DOI: 10.46882/2026/AJA/000749

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 114–121

DOI: 10.46882/2026/AJA/000748

Article Type: Original Research Article

Title: Prevalence, Antimicrobial Resistance Profiles, and Virulence Genes of Salmonella Species Isolated from Commercial Broiler Farms in Southern Ghana

Names of Authors: Ebenezer K. Appiah¹, Sylvia A. Takyi¹, Richmond O. Boateng²

Authors’ Affiliations: ¹Department of Animal Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; ²Veterinary Services Directorate, Ministry of Food and Agriculture, Accra, Ghana

Abstract: The intensive use of non-therapeutic antibiotics in commercial poultry setups across sub-Saharan Africa accelerates the rise of multi-drug resistant (MDR) zoonotic pathogens. This study investigated the prevalence, antimicrobial susceptibility profiles, and key virulence genes of Salmonella species contaminating commercial poultry farms in the Greater Accra and Ashanti regions of Ghana. A total of 320 samples, including cloacal swabs, boot swabs, and litter samples, were gathered from 40 operational broiler farms. Pathogens were isolated via standard culture methods, and confirmed using PCR assays targeting the invA gene. Susceptibility testing across 12 commercial antibiotics was run using the disk diffusion method. The overall Salmonella isolation rate stood at 22.8% (73/320), with litter samples displaying the highest contamination. Molecular testing verified that 100% of the isolates carried the invA virulence gene, while 64.3% contained the stn enterotoxin gene. High resistance levels were observed against Ampicillin (88.4%), Tetracycline (82.1%), and Ciprofloxacin (54.6%). Alarmingly, 58.9% of the confirmed isolates displayed an MDR profile, resisting three or more distinct chemical classes. These findings reveal an elevated prevalence of pathogenic, drug-resistant Salmonella strains in Ghana’s poultry hubs, highlighting the urgent need for stringent biosecurity guidelines and enforced antimicrobial stewardship.

Keywords: Salmonella enterica, Antimicrobial resistance, Broiler poultry, Virulence genes, Zoonosis, Public health

Manuscript Timeline: Received: May 28, 2026; Revised: July 02, 2026; Accepted: July 28, 2026; Published: August 31, 2026

Citation: Appiah, E. K., Takyi, S. A., & Boateng, R. O. (2026). Prevalence, Antimicrobial Resistance Profiles, and Virulence Genes of Salmonella Species Isolated from Commercial Broiler Farms in Southern Ghana. African Journal of Agriculture, 13(8), 114–121. DOI: 10.46882/2026/AJA/000748