Development of successful biological weed control can help to resolve various environmental challenges created by the chemical and mechanical weed control. The current study is aimed at investigating the potential of allelopathic bacteria (hereinafter as AB) for biological weed control in wheat rather than the traditional areas of plant allelopathy, phyto-pathology, and insect biocontrol agents. Eleven strains of AB were obtained that were inhibitory to little seed canary grass of which 5 also inhibited wheat in our previous studies. The remaining strains indicated the potential for biological control of this weed in wheat. Five efficient strains were selected for this purpose to conduct pot and field trials. Seeds of little seed canary grass were sown together in potted soils with wheat seeds inoculated with AB strains. A subsequent field trial was conducted at a site selected based on chronic infestations of canary grass. Seeds of the weed and inoculated wheat were co-seeded directly in field soil. For inoculation, these strains were formulated in sterilized peat and applied to seeds. In pot trials, the invasion of little seed canary grass in wheat reduced wheat grain yield up to 59.9%. Four strains suppressed the weed which resulted in recovery wheat grain yield losses from 20.1 to 66.9%. The field trial showed that the invasion of little seed canary grass reduced wheat grain yields up to 53.9%. Four strains suppressed the weed which resulted into recovery of grain wheat grain yield losses 34.3 to 64.3%. These findings were consistent with improvement of other agronomic, physiological, and chemical parameters of the crop where the four strains of AB (L9, T42, 7O0, and O010) were applied.
Keywords: Allelopathic bacteria; Biological control; Little seed canary grass; Rhizobacteria; Weed control; Weed invasion; Wheat.