Biology subjects

Agbetiameh, D.

Publications and source records attributed to Agbetiameh, D..

2 recordsLinked to original sources

bioRxiv2026

Potential of Bacillus subtilis as a biological control agent against three rot-causing pathogens in seed yams

Ghana is the largest exporter of yams in West Africa. However, yam production, particularly seed yam production, is constrained by storage rot during the off-season. Farmers seldom use synthetic pesticides to control seed yam rot. However, these are costly and pose adverse health risks to farmers. Biological antagonists offer a sustainable, relatively cost-effective, and safe alternative to synthetic pesticides. Therefore, this study aimed to test the efficacy of Bacillus subtilis as an alternative to synthetic pesticides. Bacillus subtilis supplied through the biofungicide Serenade ASO (Bayer) was assayed against three storage-rot pathogens: Lasiodiplodia theobromae, Aspergillus niger, and Rhizopus sp. These pathogens were previously isolated from the tissues of rotten seed yams. The efficacy of the bacterium was tested at concentrations of 17 %, 33 %, and 50 % in both in vitro and in vivo bioassays. B. subtilis (50 %) completely inhibited the growth (100 %) of L. theobromae in the in vitro studies. In contrast, there was little to no growth inhibition of the other two test fungi. In the in vivo assay, B. subtilis (50%) significantly (P < 0.01) inhibited L. theobromae, resulting in minimal rot lesions. However, B. subtilis (50 %) was ineffective against the other two test pathogens, resulting in large rot lesions on the seed yams. This suggests that B. subtilis could be an ideal alternative to synthetic pesticides for controlling L. theobromae on seed yams.

plant biology↗

bioRxiv2024

In vitro bio-activity of three potential antagonistic fungi against selected plant pathogens in Ghana

In the quest of developing sustainable strategies for the management of diseases affecting major crop species, this study screened three antagonists, viz. Trichoderma asperellum., Penicillium citrinum. and Myxotrichum stipitatum., for inhibitory activity against seven plant pathogens, viz. Pestalotia heterocornis, Curvularia eragrostidis, Lasiodiplodia theobromae, Sclerotium rolfsii, Colletotrichum gloeosporioides, Aspergillus flavus, and A. parasiticus on Potato Dextrose Agar (PDA) plates using the dual culture method. For each potential antagonistic fungus-pathogen combination, four replicated dual culture plates were prepared and laid out in a completely randomized design (CRD). Control plates with only the pathogens and no antagonistic fungi were also established. All assay plates were incubated at 28 (approx.) and the diameters of the pathogen in both the dual culture and control plates were measured at 6, 10 and 14 days. Percentage inhibition of fungal pathogens were calculated and used to draw a colony reduction curve for each antagonist-pathogen interaction. Areas Under the Colony Reduction Curves (AUCRCs) were calculated. Of the three antagonistic fungi tested, Trichoderma asperellum. was the most effective in inhibiting colony diameters of all seven pathogens with an average AUCRC of 813.19 % days, followed by the Penicillium citrinum. (519.25 % days). The weakest antagonist was Myxotrichum stipitatum sp. with an AUCRC of 440.6. % days. The results of the study suggest that T. asperellum and P. citrinum could be exploited for plant disease biocontrol.

microbiology↗