Department of Biological Sciences

Permanent URI for this communityhttp://itsupport.cu.edu.ng:4000/handle/123456789/28749

Welcome to the Department of Biological Sciences

Browse

Has files: YesSubject: search.filters.subject.Biocontrol

Search Results

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Post-germination Application of Trichoderma asperellum for the Biocontrol of Macrophomina phaseolina in Cowpea
    (Tropical Journal of Natural Product Research, 2025) Oyesola, Olusola L.; Kinge, Tonjock R.; Kolade, Olufisayo A; Obembe, Olawole O
    Cowpea (Vigna unguiculata (L.) Walp.) serves as a food source for humans and forage for animals. However, its production is affected by disease-causing fungi, of which Macrophomina phaseolina is a significant pathogen. Trichoderma was employed as a biofungicide to manage the disease in the screenhouse. Three strains of Trichoderma asperellum were isolated from the soil. The fungal spore suspensions of the Trichoderma strains were prepared, formulated into seven different treatment combinations, and applied to the cowpea potted soil five days after the germination of the cowpea to investigate their biocontrol ability on M. phaseolina and assess their effects on cowpea growth. The experiment's results showed that cowpea plants treated with T. asperellum differed significantly in plant height, stem girth, and leaf number compared to those treated with M. phaseolina alone (p < 0.05). Trt3 (54.6815 cm), Trt1 (54.0125 cm), and Trt5 (52.9375 cm) gave a higher plant height than in control 1 (M. phaseolina-treated cowpea - 44.9667 cm). Also, Trt7 (0.5413) and Trt3 (0.5258) gave a higher stem girth than in control 1 (M. phaseolina-treated cowpea - 0.3333 cm), while Trt6 (20.292) gave a higher leaf number than in control 1 (M. phaseolina-treated cowpea - 8.833). Additionally, Trt3 and Trt7 exhibited disease incidences of 22% and 67%, respectively, compared to control 1, which had a 100% incidence. Meanwhile, Trt7 showed 8% disease severity, compared to control 1, which had 100%. Therefore, post-germination Trichoderma application proved to be an effective strategy for controlling M. phaseolina, and it also has the potential to enhance cowpea biomass for sustainable food security.
  • No Thumbnail Available
    Item
    Evaluating Pre-Planting Trichoderma asperellum Application for Bocontrol of Macrophomina phaseolina in Screenhouse-Grown Cowpea
    (Tropical Journal of Natural Product Research, 2025) Oyesola, Olusola L.; Kinge, Tonjock R.; Kolade, Olufisayo A.; Obembe, Olawole O.
    Cowpea is recognised for its importance as a food and forage crop for animals. However, Macrophomina phaseolina, a fungus that causes pre-harvest crop loss, affects its production. In this study, Trichoderma was employed as an alternative to synthetic fungicides that negatively impact biodiversity to manage rot disease in cowpea. Three strains of Trichoderma asperellum were isolated from the soil. The spore suspensions of the Trichoderma strains were formulated into seven treatment combinations and applied to the cowpea soil before planting to investigate their biocontrol potential on M. phaseolina and their effects on cowpea biomass. The result showed that Trt3 (54.5417 cm), Trt1 (54.0625 cm) and Trt4 (52.8250 cm) had higher plant height than the negative control (M. phaseolina only (44.9667 cm)). Also, Trt7 (0.5446 cm) and Trt5 (0.5313 cm) had a higher stem girth performance than in the negative control (M. phaseolina only (0.3333 cm)), while Trt7 (24.958), Trt3 (21.417) and Trt6 (20.083) recorded a higher leaf number than in the negative control (M. phaseolina only (8.833)). Zero disease incidence was observed in Trt3 (0%) and Trt7 (0%) upon treatment with the Trichoderma formulations. Zero disease severity was recorded in Trt3 and Trt7 (0%), compared to the negative controls, which displayed 100% disease incidence and severity. The pre-planting Trichoderma application enhanced cowpea biomass and reduced disease incidence and severity compared to the negative control. Therefore, Trichoderma is an effective bioagent for controlling diseases caused by M. phaseolina in cowpea and stimulating its overall performance.
  • No Thumbnail Available
    Item
    EVALUATION OF EFFECTS OF Trichoderma asperellum STRAINS IN BIOCONTROL OF CHARCOAL-ROT CAUSING Macrophomina phaseolina (Tassi) Goidanich IN COWPEA
    (Covenant University Ota, 2025-09) OYESOLA, Olushola Luke; Covenant University Thesis
    Macrophomina phaseolina, a soil-borne fungal pathogen, is responsible for loss in cowpea at both seedling and adult stages. Synthetic fungicides, although proven effective in M. phaseolina control, lead to severe cowpea poisoning and pose significant health risks to humans and animals. Trichoderma are efficient bioagents for managing plant pathogens, representing a promising strategy for managing M. phaseolina. This study evaluated the antifungal efficacy of some Trichoderma asperellum strains against M. phaseolina. The Trichoderma isolates obtained from soil were macroscopically, microscopically and genotypically identified based on the Internal Transcribed Spacer genes. Bioactive compounds were isolated from selected Trichoderma species and evaluated using Gas Chromatography-Mass Spectrometry (GC-MS). The inhibitory potential of the suspensions of selected Trichoderma species against M. phaseolina was tested singly in vitro and in combination in vivo. The in vivo experiments were carried out in the screenhouse across pre-planting, post-germination and seed treatment for eighty days, and plant growth indicators such as plant height, stem girth and leaf number were assessed at ten-day intervals. Disease incidence and severity were also determined following standard methods. After the termination of the in vivo experiment, yield assessment was carried out to determine the cowpea pod number, pod weight, and seed number, as well as the fresh and dry weights of leaves, stems and roots. A histopathological assessment was carried out on the lower stems of the cowpea plants to determine the effect of M. phaseolina on the cowpea tissues. Phenotypic, microscopic and genotypic characterisation identified all the Trichoderma isolates as Trichoderma asperellum. Among the Trichoderma species isolated and tested, T. asperellum (Tric13), T. asperellum (Tric4) and T. asperellum (Tric12) exhibited significant inhibitory potential (p<0.05) against M. phaseolina in vitro, with inhibition values of 82.51%, 82.41%, and 81.95%, respectively. The production of volatile organic compounds varied among the Trichoderma species. Specifically, Tric13 yielded terpenoids, ketones, sesquiterpenes, cycloalkanes, and alcohols. In contrast, Tric4 produced fatty acids, aldehydes, alkanes, terpenoids, and aromatic and bicyclic compounds, while Tric12 generated carboxylic acids, terpenoids, phenolics, bicyclic and aromatic compounds. The in vivo results showed that Trt7 (plant height = 49.8000 cm; stem girth = 0.53625 cm; leaf number = 21.028), followed by Trt3 (plant height = 49.8250 cm; stem girth = 0.49986 cm; leaf number = 18.611), recorded higher cowpea biomass across the Trichoderma formulations than the negative control. Zero disease incidence was observed in Trt3 and Trt7 (0%) upon treatment with the Trichoderma formulations. Also, zero disease severity was noted in Trt3 and Trt7 (0%), compared to the negative controls, which displayed 100% incidence and severity. The cowpea yield assessment showed that the highest pod weight (11.3 g) and pod number (8) were recorded in Trt7 (pre-planting), and seed number (32) was recorded in Trt5 (seed treatment). The histopathological assessment of the cowpea showed the efficacy of the treatments in inhibiting the growth of M. phaseolina, minimising its tissue entry, and xylem vessel occlusion. This study established the efficacy of Trichoderma in M. phaseolina biomanagement and the synergistic potential of different Trichoderma asperellum strains in its biocontrol.