Asian Journal of Research in Crop Science

Synergistic Impacts of Microplastic Pollution and Climate Extremes on Crop Productivity: Multi-Omics Insights and CRISPR/Cas9-Mediated Mitigation Strategies

Peter Makieu — 2026-05-08

Convergent environmental pressures, including accelerating climate extremes and pervasive microplastic contamination of agricultural soils, pose compounding threats to global crop productivity that remain poorly characterized at the mechanistic level. In this PRISMA-compliant systematic review of 142 peer-reviewed studies (2015–2026), we integrate multi-omics evidence (transcriptomics, proteomics, and metabolomics) to elucidate molecular reprogramming underlying the combined effects of drought, heat, and microplastic stress in major crops. Polyethylene microplastics reduce soil water-holding capacity and increase ammonia volatilization by up to 33.9%, while nanoplastic uptake induces reactive oxygen species accumulation and lipid peroxidation. Key transcription factor families, including DREB, NAC, and MYB, emerge as central regulatory hubs under dual stress. We propose a tripartite mitigation framework that (i) leverages CRISPR/Cas9-mediated editing of stress-responsive loci (OST2, SAPK2, ARGOS8, BnaA9.NF-YA7) for intrinsic resilience; (ii) implements IoT-enabled precision irrigation and hyperspectral monitoring for real-time stress management; and (iii) employs biochar-assisted physical sorption and synthetic microbial communities to restore soil health. This integrative synthesis provides actionable guidance for experimental validation, identifies priority CRISPR targets, and highlights knowledge gaps in long-term microplastic degradation and stress interaction, offering a mechanistic and translational roadmap for developing climate- and microplastic-resilient crops.

Effects of Eichhornia crassipes Aqueous Extract and Organic Manure on Root Gall Severity in Beetroot (Beta vulgaris) in Togo

Yao Félicité Amenuti — 2026-03-19

Plant-parasitic nematodes of the genus Meloidogyne represent a major constraint to beetroot production in Togo. This study, conducted at the Agronomic Experimental Station of the University of Lomé, aimed to evaluate the combined effectiveness of organic manure and aqueous extracts of water hyacinth (Eichhornia crassipes) in nematode management and yield improvement. The experiment was arranged in a split-plot design with nine treatments and three replications, In this experiment, the main plot factor consisted of three organic manure application rates (0, 10, and 15 t/ha), while the subplot factor consisted of three formulations: Furadan, aqueous extract from the aerial parts of water hyacinth, and aqueous extract from the submerged parts of water hyacinth..Results showed that organic manure and aqueous extracts enhanced nematode control and promoted plant growth. The combination of 15 t/ha organic manure with Furadan reduced soil nematode density by 60.69%. In roots, the greatest reduction (65.03%) was obtained with 15 t/ha manure combined with the submerged-part extract, lowering the mean nematode population to 5.01 individuals. This treatment also produced the highest root yield (54.25 t/ha). The lowest gall index (1.93) was recorded under the same treatment, corresponding to a 69.56% reduction in infestation compared with Furadan alone. These findings suggest that the integration of organic manure with water hyacinth extract, particularly the submerged-part extract, may serve as an effective alternative approach for nematode management in beetroot production.

Adaptation and Agronomic Characterization Trials of 14 Rice Genotypes in Contrasting High-Altitude Marshes of Gisha and Akagoma, Ngozi Province, Burundi

Privat Rwasa — 2026-03-21

Rice is a strategic crop for food security and sustainable development in Burundi, yet its productivity in high-altitude marshes remains severely constrained by low nighttime temperatures (<15°C), which induce spikelet sterility during reproductive stages. Despite breeding efforts by ISABU, FACAGRO, and IRRI, the availability of high-yielding, stable varieties adapted to these medium-altitude ecological conditions remains limited. Understanding genotype × environment (G×E) interaction is essential for identifying superior genotypes that combine high yield potential with stability across diverse environments, thereby supporting targeted breeding programs. This study evaluated the agronomic performance and stability of 14 rice varieties, 11 from ISABU preliminary trials and 3 locally cultivated, in the high-altitude marshes of Gisha and Akagoma (Ngozi Province) during the 2013–2014 growing season. Using a randomized complete block design with three replications, nine agronomic and yield-related traits were analyzed through two-way ANOVA, multiple regression, and the AMMI model to dissect G×E interaction. Multiple regression analysis revealed that effective tillering, thousand-grain weight, spikelet sterility rate, and total grains per panicle significantly influenced paddy yield (R² = 0.512; p < 0.001), highlighting these components as key selection criteria for direct breeding improvement. ANOVA demonstrated highly significant differences between sites and varieties for plant height, grains per panicle, thousand grain weight, sterility rate, and yield (p < 0.001). The AMMI analysis identified varieties UNG, 74, 71, and 46 as exhibiting general adaptation across both sites, with UNG combining the highest mean yield (6.4 t/ha) with superior stability. Varieties 54 and 12 achieved exceptional yields (7.58 and 6.02 t/ha, respectively) but displayed specific adaptation to Akagoma conditions. These findings provide evidence-based recommendations for varietal dissemination and selection criteria to enhance rice productivity in Burundi's high-altitude zones. Multi-season and multi-location testing is recommended to further validate stability patterns and support breeding strategies for climate-resilient rice varieties.

Multi-Environments Evaluation of Elite Mutant Lines of Improved Ginger for Yield Stability and Selection

G. A. Iwo — 2026-03-24

A multi-location evaluation of 15 improved elite ginger mutant lines was conducted in the 2023 and 2024 cropping seasons across 10 states in Nigeria. The states were Abia, Bauchi, Benue, Borno, Cross River, Kaduna, Nasarawa, Osun, Plateau and FCT. The objective of the work was to evaluate the newly developed improved ginger lines across the major producing areas in Nigeria to ascertain their yield potential, yield stability,adaptability and suitability for selection. The experiment was laid out in a Randomized Complete block Design with 3 replications. Data were collected on yield- related traits including plant height, number of tillers per plant, number of rhizome fingers, rhizome length and rhizome yield.The combined analysis of variance showed that Genotype, Environment, Genotype by Environment Interaction(GEI) and Years were significant at P< 0.01 and P< 0.05 for all yield related traits but no significant difference in G xY interaction in rhizome yield. Multivariate analysis using AMMI and GGE biplots was performed to identify stable and high- yielding ginger mutant lines. The AMMI analysis of variance showed a high level of environmental effect, accounting for a larger percentage of 66.5% (plant height) , 52.43% (rhizome fingers), 46.26% ( numbers of tillers) ,40.95% (rhizome length) and 49.10% (rhizome yield) of the total variation across all yield components. The interaction sum of squares was partitioned into IPCA 1 and IPCA 2 which joinly accounted for the total variations with IPCA 1 being significant in plant height (10.85%) ,Tillers (9.0%), rhizome fingers (8.05%) , rhizome length (5.53%) and rhizome yield(8.06%) .The GGE biplot analysis was used to visualize the relationship between tester environment and the ginger mutant lines to determine the Which-Won-Where portion which reveals the stability of genotypes. The GGE biplot explained 88.2% of the total variation in rhizome yield attributable to genotype and GE interactions. The E4 (Cross River) and E10 (Abia) were the most discriminatory environments for rhizome yield. The polygon view of the GGE biplot for rhizome yield identified the best genotypes for the environment and the result showed G13(UG2-5-49) as winner in the mega environment of E4(Cross River) and E10(Abia). Two environments E1 (Bauchi) ,E7 (FCT) favors UG2-5-04, UG2-5-52, UG2-9-01, UG1-13-02) while the environments E2 (Benue) ,E3 (Borno), E5(Kaduna), E8,(Osun) and E9 (Plateau) favors UG1-11-07, UG1-5-31 and UG2-5-48. From multiple environment testing, five best- performing genotypes with relative stability across all yield attributes were identified and selected. These genotypes are UG1-11-03, UG1-13-02, UG2-5-04, UG2-5-49 and UG2-9-01. These genotypes will be recommended for registration and release to farmers.

Availability of N from Prilled Urea, USG and Manures to Flooded Boro Rice in Bangladesh

Md. Shahidul Haque Bir — 2026-03-26

This study was conducted at the Bangladesh Agricultural University farm during the Boro season of 2025 to find out the effect of prilled urea (PU), and urea super granules (USG), applied alone or in combination, with poultry manure or cowdung on field water properties, nitrogen use efficiency, and the yield of BRRI dhan50. The treatments were: T₁ (Control), T₂ (78 kg N ha^-1 from USG), T₃ (136 kg N ha^-1from prilled urea), T₄ (58 kg N ha^-1 from USG), T₅ (58 kg N ha^-1 from USG + 3 t ha^-1 poultry manure), and T₆ (58 kg N ha^-1 from USG + 5 t ha^-1cowdung). Application of fertilizers and poultry manure (T₅) significantly increased the highest grain yield of 4700 kg ha^-1 as well as the highest straw yield of 5888 kg ha^-1. T₂performed better than T₃ which was statically significant and indicated the superiority of USG over prilled urea. Yield performances of both T₂ and T₅ remained statistically similar, and they both differed significantly over the rest of the treatments. In rice field water, urea super granules (USG) gradually released available NH₄⁺-N and maintained its presence throughout the entire growth period, in contrast to prilled urea, indicating the beneficial role of USG. Other water properties, including pH and electrical conductivity (EC), were also affected by the application of both prilled urea and USG. Overall, the results suggest that the combined application of USG and poultry manure is more effective for rice production, as it reduces nitrogen losses, conserves nitrogen, and enhances the efficiency of applied nitrogen.

Knowledge of Termite (Order: Isoptera) Infestations among Crops and Its Control Methods Employed in Danko/Wasagu, Kebbi State, Nigeria

H. A. Shindi — 2026-04-02

Termite infestation is a significant limitation to crop production by smallholder farmers in the study area, but the awareness, perceptions, and management practices by farmers have not been welcomed. This study was conducted to assess the pattern of termite infestation on crops and the control methods employed by farmers. One hundred structured questionnaires were used to collect data from respondents and the data were analysed using descriptive statistics. Findings showed that most of the respondents were male (83 percent) and married (73 percent) people with different education and farm experience. All of the respondents knew termites to be pests of the crop as roots (32%), flowers (29%), and cereals and tuber crops were the most frequently attacked. Physical (48%), chemical (33%), biological (12%), and cultural (7%) forms of control methods were used by the farmers, but 48 percent of the cases re-infested, indicating the difficulty in using single control methods. The paper demonstrates the necessity to implement integrated termite management (ITM) as a form of combining indigenous knowledge, cultural practice with physical approaches and selective use of chemicals or botanical agents. Therefore, the adoption of integrated termite management (ITM), combining indigenous knowledge with cultural, physical, biological, and selective chemical methods, is essential for sustainable termite control and improved agricultural productivity.

Role of Bio-fertilizers in Availability of Phosphorus Fertilizer and Yield of Blackgram (Vigna mungo L.)

Ayushi Maurya — 2026-04-15

The present study aimed to determine the effect of Bio-fertilizers and level of Phosphorus on growth and yield of Blackgram (Vigna mungo L.). The field experiment was carried out during the Summer season 2023 at Shraddhey Bhagwati Singh Agriculture Farm, Hazipur, C.B.G. AG. PG. College, B.K.T., Lucknow, (U.P.). The experiment was laid out in FRBD with 12 treatment combination along with three replications. The result showed that the growth parameter viz. plant stand, plant height, number of branches, dry matter accumulation and leaf area index significantly increased due to application of T₁₂ (Rhizobium seed treatment @ 20g/kg seed+ PSB soil application @5kg/ha+60kg P₂O₅) .Yield attributes viz. number of pods/plant, number of grains/pod, weight of pods/plant ,weight of seeds/plant (and 1000 grain weight ,grain and straw yield ,total biological yield and harvest index, quality and economics of Black gram was significantly increased by the T₁₂ (Rhizobium seed treatment @ 20g/kg seed+ PSB soil application @5kg/ha+60kg P₂O₅) .However the highest B:C Ratio was resulted due to the application of(Rhizobium seed treatment @ 20g/ka seed+ PSB soil application+40kg P₂O₅).Rhizobium, and PSB along with phosphorus level was the superior among others treatments.

Evaluation of Promising Varieties of Sunflower against Major Sucking Insect Pests and Eco-safe Pest Management

Tahmina Akter — 2026-04-16

Presently jassid, whitefly and aphid have emerged as the new serious sucking insect pest complex on sunflower. This study evaluated the effectiveness of three sunflower varieties (BARI Sunflower-2, BARI Sunflower-3, and the hybrid variety Mayabi) against them and assessed some pest control methods (T₂= yellow sticky traps with Trichogramma spp. and Microbracon sp. release, T₃= egg mass collection with Carbaryl spray and T₄= pheromone traps with chlorpyriphos spray) against these insects at Sher-e-Bangla Agricultural University, Bangladesh. A two-factorial randomized complete block design with three replications tested these three pest management treatments over control (p = .05). Mayabi was most susceptible variety to these pests, while BARI Sunflower-2 showed the highest resistance and had the highest seed yield (1.72 Ton/hectare). Pheromone traps with chlorpyriphos (T₄) effectively reduced pest populations and with increased yield and BARI sunflower- 2 (V₁) while V₁T₄ treatment combination were recorded as the lowest seed yield with high infestation_. The overall results indicate that combined pest management strategies effectively reduced insect pest incidence on sunflower compared to the untreated control (T₁) and susceptible varieties. Integrated pest management combining resistant varieties with eco-friendly strategies to enhance sunflower yield and reduce environmental hazards is a continuous field of research for sustainable agriculture.

Effect of Different Stages of Pinching on Growth and Yield of Fenugreek (Trigonella foenum-graecum L.)

R. Sarker — 2026-04-18

Fenugreek (Trigonella foenum-graecum L.) is a multipurpose leguminous crop valued as a spice, leafy vegetable, and medicinal plant, known for its rich nutritional composition and significant nutraceutical and pharmaceutical properties. Its growth, yield, and quality are highly influenced by agronomic practices such as sowing time and pinching, which regulate plant development and source–sink relationships. The experiment was conducted at the Spices Research Sub-Centre, Faridpur, during the rabi season of 2023–2024 to evaluate the effects of different stages of pinching on the growth and yield of fenugreek. The study was laid out in a Randomized Complete Block Design (RCBD) with three replications to ensure statistical reliability of the results. The findings demonstrated that different stages of pinching exerted a positive influence on all the growth and yield parameters studied. Observations on plant height, number of branches per plant, number of pods per plant, pod length, and number of seeds per pod were recorded at various intervals after sowing. In addition, data on 1000-seed weight and overall seed yield were collected at the time of harvest. Highest yield (3222.1 kg/ha) was found from plant pinching at 35 days after sowing and the lowest yield (2494.7 kg/ha) was obtained from no pinching treatment. Almost all parameters showed better result when plants were pinched at 35 days after sowing than plants pinched at 25 and 45 days after sowing and no pinching. These findings suggest that pinching at 35 days after sowing is the most effective stage for optimizing growth and maximizing yield of fenugreek under the given agro-climatic conditions.

Growth and Yield Performance of Sweet Potato Using Organic Fertilizer on an Ultisol

O. R. Akata — 2026-04-20

Continuous cultivation of sweetpotato (Ipomea batatas) on nutrient-depleted soils is a major cause of low yield in tropical Africa. This study evaluated the effect of two organic fertilizers Monty liquid and pig manure on the growth and yield performance of sweetpotato grown on an Ultisol in Akwa Ibom State, Nigeria. A randomized complete block design (RCBD) was used with three treatments: Monty liquid organic fertilizer, pig manure, and a control (no fertilizer). Data were collected on number of leaves, number of branches, vine length, leaf area index (LAI), biomass yield, and root yield. Although statistical analysis revealed no significant differences (p > 0.05) among treatments, numerical variations indicated that pig manure tended to improve vegetative growth and tuber yield compared to Monty liquid and the control. Pig manure produced the highest biomass yield (12.88 t/ha) and root yield (8.41 t/ha), followed by Monty (7.24 t/ha biomass; 6.66 t/ha root yield) and the control (7.00 t/ha biomass; 5.47 t/ha root yield). These findings suggest that organic fertilizer application, particularly pig manure, can improve sweetpotato productivity on nutrient-poor Ultisols.

Enhancing Soybean Productivity through Cobalt and Molybdenum: Seed Priming Versus Foliar Application

Eman, A. Fayed — 2026-04-23

Micronutrients, although required in small quantities, play critical roles in legume physiology and biological nitrogen fixation (BNF), making their management critical in soybean production systems. This study was conducted during the 2024 and 2025 seasons to evaluate the effects of cobalt (Co) and molybdenum (Mo), applied through seed priming and foliar spraying, on the growth, yield, and seed quality of three soybean (Glycine max L.) genotypes (H18L54, Masry 10, and Giza 111). A factorial experiment was arranged in a randomised complete block design (RCBD) with three replicates under field conditions, while laboratory experiments followed a completely randomised design with four replicates. Data were analysed using analysis of variance (ANOVA), and means were compared using the revised least significant difference (RLSD) test at a 5% probability level. Results indicated that plant height, 100-seed weight, number of pods, oil content, seed yield, and flowering time were significantly affected by treatments and genotypes, whereas their interaction was mostly non-significant under field conditions. Giza 111 exhibited superior performance in plant height of 103.3 cm and the highest seed yield of 2571.1 kg/fed. In contrast, Masry 10 recorded the highest 100-seed weight at 18.5 g. reflecting significant genotypic variation. Cobalt seed priming was the most effective treatment, significantly enhancing germination rate, seedling vigour, shoot length, and seedling biomass, with notable interaction effects under laboratory conditions. Molybdenum treatments showed moderate effects, whereas foliar applications were generally less effective than seed priming. Overall, cobalt and molybdenum applications, particularly through seed priming, can be considered an effective strategy to improve soybean productivity and seed quality by enhancing nitrogen metabolism and early seedling performance.

Next-Generation Farming: The Role of Nanotechnology in Agricultural Sustainability

Nimisha Singh — 2026-05-05

Nanotechnology offers promising solutions for improving agricultural productivity and sustainability through precise nutrient delivery and crop protection. This review examines recent progress in agricultural nanotechnology, focusing on nano-fertilizers, nano-pesticides, soil and water management, and food packaging. We conducted a systematic literature survey using peer-reviewed research articles, reports, and reviews published in recent years. We compared nano-enabled agricultural inputs with conventional agrochemicals based on efficiency, environmental impact, and performance. The analysis shows that nano-fertilizers significantly improve nutrient use efficiency and crop yield through controlled release mechanisms. Nano-pesticides enhance pest management effectiveness at lower application rates, reducing environmental contamination. Additionally, nanomaterials improve soil moisture retention and extend food shelf life through active packaging technologies. Despite these benefits, concerns about environmental impact, toxicity, and regulations remain significant challenges. Overall, these findings suggest that agricultural nanotechnology has strong potential to support sustainable farming systems, as long as its development and use are guided by careful risk assessment and responsible management practices.

Nutritional and Anti-nutritional Trade-offs among Elite Sorghum (Sorghum bicolor L. Moench) Genotypes Revealed by Multivariate Analysis

Naaman Arodi — 2026-05-09

Background: Sorghum is a climate-resilient staple crop in sub-Saharan Africa with significant nutritional potential, though its utilization is constrained by variability in grain quality and the presence of anti-nutritional factors.

Aims: To evaluate nutritional and anti-nutritional variability among elite sorghum genotypes and identify lines with superior profiles for enhanced food and nutrition security.

Study Design and Location: A laboratory-based experimental study conducted at the University of Nairobi, Department of Food Science and Technology, from January to April 2021.

Methodology: Ten elite sorghum genotypes were analyzed for proximate composition (protein, moisture, fat, fibre, carbohydrate, and energy) and anti-nutritional factors (total phenolic compounds and oxalates) using standard AOAC methods. Data were subjected to analysis of variance (ANOVA), and Pearson correlation analysis was used to determine relationships among traits.

Results: Significant genotypic differences (p < 0.05) were observed for protein, energy, fibre, carbohydrate, phenolic, and oxalate contents, while moisture and fat showed no significant variation. Protein content ranged from 4.20% to 12.85%, and energy values from 334.31 to 361.53 kcal/100 g. Total phenolic content was strongly negatively correlated with carbohydrate (r = −0.929, p < 0.01) and protein (r = −0.596, p < 0.05), but positively correlated with fibre (r = 0.539, p < 0.01) and oxalates (r = 0.836).

Conclusion: Substantial nutritional variability exists among elite sorghum genotypes, with clear trade-offs between macronutrient content and anti-nutritional factors. Genotypes with high protein and moderate phenolic levels show strong potential for nutrition-sensitive breeding and targeted deployment in sorghum-based food systems, particularly in arid and semi-arid regions.

Effect of Waste Engine Oil Contamination on Proximate, Phytochemical and Antibacterial Properties of Telfairia occidentalis and Zea mays

L. Imarhobobhor — 2026-05-11

Spent engine oil contamination from improper disposal in Nigeria introduces toxic hydrocarbons and heavy metals into soils, altering soil properties, reducing crop growth and yield, and potentially affecting the nutritional, phytochemical, and antimicrobial qualities of crops such as maize (Zea mays) and fluted pumpkin (Telfairia occidentalis). This study evaluated the impacts of waste engine oil on the proximate, phytochemical, and antibacterial activity of Telfairia occidentalis and Zea mays. The seeds were obtained in Benin City, Nigeria, and grown in humus soil that was mixed with spent engine oil that was obtained in a local mechanic workshop. Plant samples were harvested, processed and exposed to aqueous extraction after 21 days of growth. Based on the selected pathogenic organisms, the zone of inhibition method was used to determine antibacterial activity. It was found that the extracts at higher concentrations (80 g/100 ml) had the best antibacterial activity against all the organisms tested including those of E. coli, Staphylococcus aureus, Streptococcus, Pseudomonas aeruginosa, Proteus mirabilis and Klebsiella pneumoniae. The proximate analysis showed that lipid was the greatest (18% - 36.6%), then protein (0.175% - 5.425%).Phytochemical analysis showed that the amounts of alkaloids, saponins, flavonoids, and phenols were higher in the control plants and the amounts of these bioactive compounds were considerably decreased with the escalation of oil contamination (particularly 500 ml). Morphology also indicated retarded growth in polluted plants. On the whole, waste engine oil has a detrimental influence on plant growth and biochemical structure, but significant antibacterial activity is maintained at a higher extract concentration.

Effect of BAP (6-Benzylaminopurine) and Organic Manures on Growth and Flowering of Marigold (Tagetes erecta L.)

Nesa Okta Rida — 2026-05-12

Benzylaminopurine Benzylaminopurine (BAP) is a cytokinin plant growth regulator that plays an important role in stimulating cell division, shoot development, and the formation of generative organs, while organic manures improve soil fertility and support sustainable plant growth. This study aimed to evaluate the interaction between BAP concentrations and types of manure on the growth and flowering of marigold (Tagetes erecta L.), to determine the optimal BAP concentration, and to identify the most effective type of manure. This study employed a Randomized Complete Block Design (RCBD) with a factorial arrangement and was conducted from September to December 2025 in Bengkulu, Indonesia. The treatments consisted of two factors: BAP concentration (0, 50, 100, and 150 ppm) and manure type (chicken, cattle, and goat), resulting in 12 treatment combinations. Each treatment was replicated three times, giving a total of 36 experimental units with 108 plants. Data were analyzed using analysis of variance (ANOVA), followed by Duncan’s Multiple Range Test (DMRT) at the 5% significance level. The results showed that the interaction between BAP concentration and manure type significantly affected all observed variables (P < 0.05), including plant height, number of leaves, number of branches, days to flowering, flower diameter, flower stalk length, and number of flowers. The combination of 50 ppm BAP and chicken manure produced the best performance, with plant height reaching 46.10 cm, number of leaves 38.14, number of branches 2.33, earlier flowering at 45.33 days, flower diameter of 8.20 cm, flower stalk length of 16.80 cm, and the highest number of flowers (6.33). In conclusion, the application of 50 ppm BAP combined with chicken manure is the most effective treatment for improving the growth and flowering of marigold and can be recommended to enhance flower productivity and quality under similar conditions.

Effects of Arbuscular Mycorrhizal Fungi on Chlorophyll Content and Foliar Nutrient Yield of Amaranthus hybridus under Fusarium oxysporum Stress

J. D. Obeten — 2026-05-15

Background: The genus Amaranthus has gained global attention for its nutritionally important species cultivated as leafy vegetables and grains. However, despite their role in diversifying diets in Nigeria, the capacity of arbuscular mycorrhizal fungi (AMF) to mitigate pathogen stress in sandy loam soils remains poorly understood.

Aim: This study evaluated the effects of AMF on chlorophyll content and foliar nutrient yield of Amaranthus hybridus under Fusarium root rot stress in a pot experiment.

Study Design: The experiment was structured as an 8 × 3 completely randomized design, consisting of eight treatments with three replicates each, resulting in a total of 24 pots.

Place and duration of study: The study was conducted in Calabar, located in the south-south region of Nigeria, between February and May 2025.

Methodology: Amaranthus hybridus seedlings were inoculated with two arbuscular mycorrhizal fungi (AMF) strains, Glomus mosseae and Glomus gigaspora. The inocula comprised spores, mycelia, and infected root fragments. Prior to sowing, 50g of crude inoculum was applied 3cm below the soil surface in AMF-treated pots. Following thinning at one week after emergence, uniform seedlings height was selected and inoculated with 50mL of Fusarium spore suspension under field conditions.

Results: Inoculation of Amaranthus hybridus seedlings with arbuscular mycorrhizal fungi (AMF) reduced the severity of Fusarium root rot. Seedlings treated with the combined AMF inoculation of Glomus mosseae and Glomus gigaspora in the presence of Fusarium (Gm⁺Gg+Fo) recorded the lowest disease severity among infected plants, indicating effective suppression of pathogen activity. Plants treated with Glomus mosseae in combination with Fusarium (Gm⁺Fo) showed improved chlorophyll b and total chlorophyll contents, with mean values of 105.66μg/g⁻¹FW and 206.48μg/g⁻¹FW, respectively, compared with pathogen-inoculated plants. In contrast, seedlings inoculated with Fusarium alone exhibited marked reductions in chlorophyll a, chlorophyll b, and total chlorophyll contents. Furthermore, seedlings treated with Gm⁺Gg⁺Fo showed significant (P ≤ 0.05) increases in foliar phosphorus, potassium, and magnesium yields compared with inoculated seedlings under pathogen stress conditions. Similarly, AMF-pathogen treatments (Gm⁺Fo and Gg⁺Fo) reduced pathogen effects and produced the highest foliar nitrogen and calcium yields, with values of 14.45 and 8.07g/plant⁻¹, respectively. Conversely, Fusarium stress alone reduced foliar nutrient yield in all measured parameters. Enhanced foliar nutrient accumulation, particularly phosphorus, appears to be a key mechanism underlying disease resistance in mycorrhizal plants.

Conclusion: The findings indicate that the combined application of the AMF species Glomus mosseae and Glomus gigaspora with Fusarium oxysporum was the most effective treatment for suppressing root rot disease and improving overall plant nutrition. In contrast, the combination of Glomus mosseae and Fusarium oxysporum (Gm⁺ Fo) was more effective in enhancing leaf chlorophyll content. These results reinforce the potential of AMF species as a biological means of protecting plants against soil-borne pathogens.

Impact of Three Local Plant Extracts on Okra Flower-Visiting Insects in Bokle, North-Cameroon

Youssoufa Ousmana — 2026-05-16

Background: Okra production is often constrained by insect pest infestation, leading to significant crop damage and yield loss. Excessive use of synthetic pesticides for pest management adversely affects non-target organisms, including beneficial flower-visiting insects essential for pollination and ecosystem balance. Therefore, eco-friendly botanical extracts are being explored as sustainable alternatives for pest control.

Objective: The present study aimed to characterize the composition, structure, and functioning of the flower-visiting insect community in okra fields and to determine the impact of aqueous leaf botanical extracts on these insects for achieving effective and environmentally safe pest management.

Study Design: Ecological survey was conducted in 11 trials (four plots each).

Place and Duration of Study: Investigations were carried out in Bockle from June 15 to October 10, 2022.

Methodology: Plants were identified in-situ when possible or photographed and a sample of leaves, bark, flowers and fruits (when available) allowed identification in the laboratory by botanist colleagues. Collected insects were identified to the species level in the Laboratory of Applied Zoology (Department of Biological Sciences, Faculty of Science, University of Ngaoundere) where voucher specimens were deposited. Aqueous extracts were sprayed and flowers inspected two days a week.

Results: A total of 4,406 specimens belonged to six orders, 11 families and 14 species. Lilioceris lilii (42.2%) and Apis mellifera adansonii (12.0%) highly occurred. Extracts affected exclusively Li. lilii. Species richness was low (d=0.012 in the pooled Azadirachta indica extract to d=0.044 in 15% Eucalyptus camaldulensis plots; pooled assemblages: d=0.003). Species diversity was slightly median in pooled assemblages (H’=2.064, H’_max=2.639), low in experiments (H’=1.908; H’_max=6.644 in untreated to H’=2.255, H’_max=5.781 in 15% Senna occidentalis); highly even (J=0.723 in untreated plots to J=0.855 in 15% Se. occidentalis; J=0.782 in the pooled assemblages), four co-dominants in untreated plots, 5% and 10% Az. indica and Se. occidentalis respectively to eight species in the pooled assemblages. Assemblages fitted Zipf’s model with a high decay coefficient and fractal dimension (γ=0.986, 1/γ=1.014 in 15% Eu. camaldulensis to γ=1.362, 1/γ=0.734 in 10% Eu. camaldulensis; pooled assemblages: γ=1.203 and 1/γ=0.831). Assemblage from 15% Az. indica plots fitted Zipf-Mandelbrot with a high decay coefficient (γ=2.152), high niche diversification (β=2.578) and low fractal dimension (1/γ=0.465). Six dominant pollinators and flying insects strongly tolerated each other, repelled eight pests and shredders that in turn were weakly correlated each other.

Conclusion: Promoting pollinators and flying insects, breaking solidarity among pests and shredders, and using pollinators and butterflies as indicators (their decrease indicate imminent pests invasion) would optimize the health of Okra plants. However further studies are needed to validate reliability.

Growth Response of Vernonia hymenolepis (Sweet Bitter Leaf) Seedlings Inoculated with Arbuscular Mycorrhizal Fungi (AMF) under Fusarium Root Rot Stress in Calabar, Nigeria

J. D. Obeten — 2026-05-18

Background: Vernonia hymenolepis is an underutilized African leafy vegetable with important nutritional and economic value, but its productivity is severely threatened by soil-borne pathogens such as Fusarium oxysporum, necessitating sustainable management approaches such as the use of arbuscular mycorrhizal fungi (AMF) to improve growth and disease resistance.

Aims: To determine the influence of two AMF strains on dry biomass of root, stem and leafs of Vernonia hymenolepis under pathogen stress.

Study Design: The experiment followed an 8 × 3 completely randomized design, consisting of eight treatments with three replicates, for a total of 24 pots.

Place and Duration of Study: Calabar in the south- south of Nigeria. A study was conducted between February and May, 2025.

Methodology: Vernonia hymenolepis seedlings were inoculated with two arbuscular mycorrhizal fungi (AMF) strains Glomus mosseae and Glomus gigaspora and subsequently challenged with 50ml of a Fusarium spore suspension under field conditions. Fusarium root rot severity (FRR) and dry biomass were assessed at harvest, 12 weeks after emergence.

Results: The results clearly indicate that all the pathogen stressed seedlings alone (Fo) had higher root percentage disease severity (20.00%) than their combined counterpart with AMF seedlings (Gm⁺Fo and Gm⁺Gg⁺Fo) 1.66% as the lowest. Generally, Vernonia hymenolepis seedlings inoculated with G. mosseae in combination with G. gigaspora and Fusarium (Gm⁺Gg⁺Fo) produced the highest significant (P≤ 0.05) root, stem and total dry weight with means values of 10.01, 10.72 and 32.76g/plant^-1 . Vernonia hymenolepis plants infected with Fusarium (Fo) alone recorded the lowest severe root, stem, total and root: shoot ratio damage by the pathogen. However, inoculated seedlings with Gg, Gm⁺Fo and Gm⁺Gg⁺Fo gave the highest leaves dry weight and Gm⁺Gg⁺Fo recorded the highest root to shoot ratio with value 32.76g/g^-1.

Conclusion: Plants inoculated with arbuscular mycorrhizal fungi (AMF) are better able to withstand environmental stresses, including pathogen pressure, and can contribute to the rehabilitation of soils affected by soil-borne diseases in Calabar, Nigeria. Enhanced dry biomass accumulation represents a key mechanism through which mycorrhizal plants express resistance to pathogens.

Growth Performance and Disease Suppression in Pepper (Capsicum annuum L.) Treated with Trichoderma viride under Fusarium oxysporum and CMV Stress

D. E. Akam — 2026-05-19

Background: Capsicum annuum (pepper) is an economically important crop whose production is significantly reduced by Fusarium wilt and Cucumber mosaic virus, prompting interest in sustainable control strategies such as the biocontrol agent Trichoderma viride to improve growth and disease resistance.

Aim: This study investigated the growth performance of Capsicum annuum L. and the disease suppressive potential of Trichoderma viride under stress conditions caused by Fusarium oxysporum and Cucumber mosaic virus (CMV) in Calabar, Nigeria.

Study Design: The experiment was arranged in a Completely Randomized Design (CRD) with six treatments replicated three times.

Place and Duration of Study: The research was conducted in the Screen House and Laboratory of the Department of Plant Science and Biotechnology, University of Cross River State, Nigeria, between March and June 2025.

Methodology: Seeds of Capsicum annuum L. and sterilized soil on perforated bags were treated with Trichoderma viride before sowing. Fusarium oxysporum and Cucumber mosaic virus were inoculated two weeks after seedling emergence. Plants were maintained in a screen house for 12 weeks, during which growth parameters such as plant height and number of leaves were recorded. Disease severity was assessed using a standard disease rating scale and expressed as disease severity index.

Results: Results showed that plants inoculated with Fusarium oxysporum and CMV recorded significant reductions (p ≤ 0.05) in plant height and number of leaves, accompanied by increased disease severity when compared with the control. In contrast, plants treated with Trichoderma viride exhibited significantly improved growth performance and reduced disease severity. The highest plant height (93.56 cm) and leaf production (76.36) were recorded in plants treated with T. viride alone at 12 weeks after inoculation. The highest disease severity (5.00) was observed in plants inoculated with pathogens alone. Combined treatments involving T. viride and pathogens showed moderate growth improvement and reduced disease severity (3.00) compared with pathogen inoculated plants without biocontrol treatment.

Conclusion: The findings indicate that Trichoderma viride effectively enhances plant growth and suppresses disease under fungal and viral stress conditions. Its application offers a promising, eco-friendly alternative to synthetic chemicals in the management of pepper diseases. Therefore, the integration of T. viride into sustainable crop production and management systems is strongly recommended for improved yield and plant health in tropical agro ecological zones.