Protection of Sorghum Seedlings by Inoculums and Metabolites of Growth Promoting against Plant Pathogens

Document Type : Original Article

Authors

1 Department of Biological Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria

2 Department of Agricultural Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria

Abstract

Introduction: Plant diseases result in significant agricultural losses. Traditional methods to control these diseases, such as chemical pesticides and pathogen-resistant cultivars, have significant drawbacks, including deleterious environmental consequences. This study aimed to assess the protective potentials of inoculums and metabolites from growth-promoting rhizobacterial strains against sorghum seedlings infected by plant pathogens.
Materials and Methods: Fifteen rhizobacterial inoculums and metabolites were tested against five plant pathogens (Alternaria sp., Aspergillus niger, Corynespora sp., Fusarium oxysporum, and Xanthomonas campestris) in this study. Four treatment groups were used for the study; infected-only, metabolite- or inoculum-treated-only, infected-treated, and control-group seeds. Following planting, the final germination percentage and the vigor index of seeds in the respective groups were calculated.
Results: In general, all the pathogens showed infectivity on the sorghum seeds. In all cases, significantly higher germination percentages and vigor index values were recorded for the treated-only and the infected-treated seeds when compared with the infected-only and the control setups. This was a constant observation irrespective of the pathogens used to simulate infection or the metabolites or inoculums used for treatment.
Conclusions: The study highlights the potential of using rhizosphere bacterial strains, particularly PGPR, as biocontrol agents against important plant pathogens. Treating infected seeds with the inoculum or metabolite of these rhizobacterial strains improved seed germination and seedling vigor index compared to the infected, untreated seeds. 

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