African Journal of Agriculture

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 058–065

DOI: 10.46882/2026/AJA/000741

Article Type: Original Research Article

Title: Agronomic Performance and Nitrogen Fixation Potential of Promiscuous Soybean (Glycine max L. Merrill) Varieties in Northern Ghana

Names of Authors: Kwaku O. Asante¹, Abdulai M. Fuseini¹, Grace E. Mensah²

Authors’ Affiliations: ¹Council for Scientific and Industrial Research (CSIR)-Savanna Agricultural Research Institute, Tamale, Ghana; ²Department of Agronomy, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Abstract: Soil nitrogen depletion is a major barrier to smallholder crop productivity in the savanna zones of northern Ghana. Cultivating promiscuous soybean (Glycine max L. Merrill) varieties—which form symbiotic relationships with indigenous Bradyrhizobium strains without requiring chemical inoculants—presents a cost-effective strategy to improve soil fertility and raise family incomes. This multi-locational field experiment evaluated the nodulation efficiency, nitrogen fixation capacity, and grain yield of four advanced promiscuous soybean varieties (Jenguma, Quarshie, Songda, and Suvita) against a non-promiscuous check (Anidaso). Biological nitrogen fixation (BNF) was quantified using the nitrogen-15 (¹⁵N) natural abundance technique. The promiscuous variety Songda recorded the highest nodule dry weight (184.6 ± 12.5 mg/plant) and numerical nodule count at 50% flowering. Songda derived 72.4% of its total nitrogen requirements from atmosphere-based fixation, equating to an estimated mean of 84.6 kg N/ha returned to the soil profile. The grain yields differed significantly among varieties (p < 0.01), with Songda producing the highest clean grain yield at 2.45 t/ha, followed by Jenguma at 2.12 t/ha, compared to only 1.24 t/ha for the non-promiscuous control. Songda also maintained a high harvest index (0.46). This study demonstrates that using the Songda variety provides dual benefits, delivering high grain outputs while substantially improving nitrogen balance in savanna cropping systems.

Keywords: Biological nitrogen fixation, Glycine max, Promiscuous varieties, Nodulation, Grain yield, Savanna ecology

Manuscript Timeline: Received: April 20, 2026; Revised: May 29, 2026; Accepted: June 22, 2026; Published: August 16, 2026

Citation: Asante, K. O., Fuseini, A. M., & Mensah, G. E. (2026). Agronomic Performance and Nitrogen Fixation Potential of Promiscuous Soybean (Glycine max L. Merrill) Varieties in Northern Ghana. African Journal of Agriculture, 13(8), 058–065. DOI: 10.46882/2026/AJA/000741

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 050–057

DOI: 10.46882/2026/AJA/000740

Article Type: Original Research Article

Title: Biocontrol Potentials of Trichoderma harzianum and Pseudomonas fluorescens against Fusarium Wilt (Fusarium oxysporum) of Eggplant

Names of Authors: Mariam K. Coulibaly¹, Yao A. Koffi¹

Authors’ Affiliations: ¹UFR Agroforesterie, Université Jean Lorougnon Guédé, Daloa, Côte d'Ivoire

Abstract: Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. melongenae, causes substantial yield collapses in eggplant crops across West Africa. Chemical fungicides are expensive and raise concerns regarding environmental toxicity and pathogen resistance. This study evaluated the in vitro and in vivo biocontrol potential of Trichoderma harzianum and Pseudomonas fluorescens, applied individually and in combination, against Fusarium oxysporum. In dual-culture laboratory assays, T. harzianum and P. fluorescens restricted radial mycelial growth of the pathogen by 68.4% and 58.2% respectively. For the greenhouse trial, eggplant seedlings were grown in soil artificially inoculated with a virulent pathogen spore suspension (1.0 x 10⁶ spores/mL). The greenhouse results demonstrated that the combined application of T. harzianum and P. fluorescens as a seed treatment and root drench lowered disease incidence by 76.5% compared to the untreated infected control. This dual-inoculant treatment also reduced the plant wilt severity index to 1.2 on a 1-to-5 scale. Additionally, plants receiving the combined bio-agents showed significantly greater seedling vigor, root length, and shoot biomass than those in the single-agent and control treatments (p < 0.05). This growth enhancement is attributed to synergistic mechanisms, including mycoparasitism and induced systemic resistance, proving that dual biological treatments are a highly effective alternative to synthetic chemicals for managing fusarium wilt.

Keywords: Biological control, Fusarium oxysporum, Trichoderma harzianum, Pseudomonas fluorescens, Solanum melongena, Disease incidence

Manuscript Timeline: Received: April 11, 2026; Revised: May 20, 2026; Accepted: June 15, 2026; Published: August 09, 2026

Citation: Coulibaly, M. K., & Koffi, Y. A. (2026). Biocontrol Potentials of Trichoderma harzianum and Pseudomonas fluorescens against Fusarium Wilt (Fusarium oxysporum) of Eggplant. African Journal of Agriculture, 13(8), 050–057. DOI: 10.46882/2026/AJA/000740

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 041–049

DOI: 10.46882/2026/AJA/000739

Article Type: Original Research Article

Title: Nutrient Digestion, Rumen Fermentation Parameters, and Growth Performance of West African Dwarf Goats Fed Agro-Industrial By-Products

Names of Authors: Tunde O. Olajide¹, Segun L. Adeniyi¹, Chinedu P. Okafor²

Authors’ Affiliations: ¹Department of Animal Science, University of Ibadan, Ibadan, Nigeria; ²Department of Animal Science, University of Nigeria, Nsukka, Nigeria

Abstract: High feed prices remain a fundamental barrier to profitable small ruminant production in West Africa. Substituting conventional grains with locally abundant agro-industrial by-products can lower costs while preserving animal performance. This 90-day feeding trial investigated the effects of substituting maize with varying levels of a combined agro-byproduct blend (palm kernel cake, brewers’ dried grains, and cassava peels) on nutrient digestibility, rumen fermentation, and growth in West African Dwarf (WAD) goats. Twenty WAD bucks, weighing an average of 8.5 ± 0.4 kg, were assigned to four dietary treatments: T1 (0% byproduct blend control), T2 (25% blend substitution), T3 (50% blend substitution), and T4 (75% blend substitution). Apparent digestibility coefficients for dry matter (DM) and crude protein (CP) were high across all groups, with T3 achieving peak values of 74.2% and 72.8% respectively. Rumen liquor analysis showed that total volatile fatty acids (VFAs) increased significantly in T3 (92.4 mmol/L) compared to T1 (81.5 mmol/L; p < 0.05), indicating highly efficient microbial fermentation. Average daily weight gain was maximized in the 50% substitution group T3 (54.6 g/day) compared to the control T1 (46.2 g/day). Crucially, feed cost per kilogram of live weight gain dropped by 31.5% in the T3 group. This study confirms that replacing 50% of conventional grain inputs with this agro-industrial blend enhances growth performance and lowers production costs for goat farmers.

Keywords: West African Dwarf goat, Agro-industrial byproducts, Nutrient digestibility, Rumen fermentation, Live weight gain, Cost reduction

Manuscript Timeline: Received: April 02, 2026; Revised: May 12, 2026; Accepted: June 08, 2026; Published: August 02, 2026

Citation: Olajide, T. O., Adeniyi, S. L., & Okafor, C. P. (2026). Nutrient Digestion, Rumen Fermentation Parameters, and Growth Performance of West African Dwarf Goats Fed Agro-Industrial By-Products. African Journal of Agriculture, 13(8), 041–049. DOI: 10.46882/2026/AJA/000739

African Journal of Agriculture | Vol. 13, No. 7, July 2026 | pp. 033–040

DOI: 10.46882/2026/AJA/000738

Article Type: Original Research Article

Title: Financial Feasibility and Resource Use Efficiency of Solar-Powered Micro-Drip Irrigation Systems among Smallholders in Central Zimbabwe

Names of Authors: Tendai G. Hove¹, Ruvimbo M. Ndlovu¹, Blessing S. Sithole²

Authors’ Affiliations: ¹Department of Agricultural Economics and Extension, University of Zimbabwe, Harare, Zimbabwe; ²Chinhoyi University of Technology, Department of Irrigation Engineering, Chinhoyi, Zimbabwe

Abstract: Recurrent droughts linked to climate change have made rainfed vegetable farming highly risky in central Zimbabwe. Solar-powered micro-drip irrigation has emerged as a promising technology to secure year-round yields, but high initial capital setup costs remain a barrier for smallholders. This study assessed the financial viability and resource use efficiency of solar-powered micro-drip systems among 85 smallholder vegetable producers over a 24-month operational period. Cost-benefit analysis indicators, including Net Present Value (NPV), Internal Rate of Return (IRR), and Benefit-Cost Ratio (BCR), were calculated at a 12.0% discount rate. Water and energy productivity metrics were also determined. The economic analysis revealed that solar-powered micro-drip setups are financially viable, generating a positive mean NPV of US$ 3,450, an IRR of 24.6%, and an overall BCR of 1.62. Moving from diesel pumps to solar micro-drip irrigation cut seasonal operating expenditures by 68.0%, primarily by eliminating fuel costs. The system also demonstrated superior resource efficiency, with water productivity increasing from 3.2 kg/m³ under manual watering to 9.8 kg/m³ under drip application. Inefficiency modeling indicated that farmers who received specialized operational training achieved a 22.0% shorter payback period on their investment capital. This study confirms that despite steep upfront capital demands, solar-powered drip networks are highly profitable and efficient climate-adaptation assets.

Keywords: Solar irrigation, Cost-benefit analysis, Water productivity, Horticulture, Climate finance, Zimbabwe

Manuscript Timeline: Received: March 10, 2026; Revised: April 18, 2026; Accepted: May 14, 2026; Published: July 19, 2026

Citation: Hove, T. G., Ndlovu, M. M., & Sithole, B. S. (2026). Financial Feasibility and Resource Use Efficiency of Solar-Powered Micro-Drip Irrigation Systems among Smallholders in Central Zimbabwe. African Journal of Agriculture, 13(7), 033–040. DOI: 10.46882/2026/AJA/000738

African Journal of Agriculture | Vol. 13, No. 6, June 2026 | pp. 025–032

DOI: 10.46882/2026/AJA/000737

Article Type: Original Research Article

Title: Physiological Responses and Yield Stability of Groundnut (Arachis hypogaea L.) Genotypes under Induced Early-Season Drought Stress

Names of Authors: Amina S. Diallo¹, Ousmane M. Sanon¹, Boubacar Z. Traoré²

Authors’ Affiliations: ¹Institut de l'Environnement et de Recherches Agricoles (INERA), Ouagadougou, Burkina Faso; ²Département de Biologie Végétale, Université de Bamako, Bamako, Mali

Abstract: Early-season drought caused by shifting, erratic rainfall patterns frequently halts early plant development and cuts groundnut yields in the West African Sahel. Breeding resilient genotypes requires an objective understanding of specific physiological traits that govern drought adaptation. This field trial assessed the physiological mechanics and yield stability of eight advanced groundnut (Arachis hypogaea L.) genotypes under two moisture treatments: fully irrigated and induced early-season drought (irrigation withheld for 21 days during the vegetative stage). Physiological markers, including canopy temperature depression (CTD), relative water content (RWC), total chlorophyll retention, and stomatal conductance, were quantified. The drought treatment induced notable physiological modifications across all genotypes, but the magnitude varied. Genotypes ICGV-IS 13004 and ICGV-IS 15922 maintained a high RWC (> 76.5%) and cool canopies (CTD of 2.4 ± 0.15 °C) under severe moisture deficit. These two genotypes also restricted their chlorophyll degradation to under 12.0%. Statistical correlations demonstrated that a cool canopy during moisture stress was strongly associated with pod yield stability (r = 0.78, p < 0.01). Genotype ICGV-IS 13004 recorded the highest pod yield under drought conditions (1.64 t/ha), representing a minor 14.2% yield reduction compared to its fully irrigated counterpart, whereas sensitive genotypes suffered yield losses exceeding 48.0%. These results confirm that CTD and RWC are reliable physiological selection parameters for breeding drought-resilient groundnuts.

Keywords: Arachis hypogaea, Relative water content, Canopy temperature, Drought resilience, Pod yield, Sahel

Manuscript Timeline: Received: February 18, 2026; Revised: March 28, 2026; Accepted: April 25, 2026; Published: June 15, 2026

Citation: Diallo, A. S., Sanon, M. M., & Traoré, B. Z. (2026). Physiological Responses and Yield Stability of Groundnut (Arachis hypogaea L.) Genotypes under Induced Early-Season Drought Stress. African Journal of Agriculture, 13(6), 025–032. DOI: 10.46882/2026/AJA/000737

African Journal of Agriculture | Vol. 13, No. 5, May 2026 | pp. 017–024

DOI: 10.46882/2026/AJA/000736

Article Type: Original Research Article

Title: Efficacy of Hermetic Storage Bags in Preserving Seed Viability and Controlling Prostephanus truncatus in Maize Farms of Northern Malawi

Names of Authors: Chikondi W. Phiri¹, Limbani G. Gondwe²

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

Abstract: The larger grain borer (Prostephanus truncatus Horn) is an aggressive, destructive post-harvest pest that causes massive storage losses for maize farmers throughout East and Southern Africa. Traditional woven polypropylene bags offer zero physical protection against insect invasion, forcing smallholders to rely heavily on chemical insecticides. This study evaluated the comparative efficacy of three commercial hermetic storage bags (PICS™, GrainPro™, and Elite Bags) against conventional woven bags for protecting stored maize against P. truncatus over an 8-month period. Maize grain samples with an initial moisture content of 12.5% ± 0.3% were artificially infested with 20 active adult borers per bag and stored under ambient rural conditions in northern Malawi. Destructive sampling was conducted at 2-month intervals to monitor oxygen levels, insect mortality, grain weight loss, and seed germination rates. By month 4, oxygen concentration inside the hermetic layers dropped from 20.9% to below 4.5%, inducing 100% insect mortality across all three hermetic bag brands. After 8 months of storage, maize in the conventional bags sustained 34.8% weight loss, and germination dropped to 14.5%. Conversely, maize stored in hermetic bags suffered negligible weight loss (< 0.8%) while maintaining a seed germination rate above 88.0%. These findings demonstrate that hermetic storage technologies provide clean, chemical-free protection that preserves both food safety and seed viability.

Keywords: Hermetic storage, Prostephanus truncatus, Post-harvest loss, Seed germination, Smallholder assets, Malawi

Manuscript Timeline: Received: February 02, 2026; Revised: March 15, 2026; Accepted: April 05, 2026; Published: May 12, 2026

Citation: Phiri, C. W., & Gondwe, L. G. (2026). Efficacy of Hermetic Storage Bags in Preserving Seed Viability and Controlling Prostephanus truncatus in Maize Farms of Northern Malawi. African Journal of Agriculture, 13(5), 017–024. DOI: 10.46882/2026/AJA/000736