Pamela A. Harris and Phillip W. Stahlman
1991 Proc. West Soc. Weed Sci. 44: 115Abstract.
Few chemical herbicides are currently available for adequate and cost-effective control of winter annual Bromus
spp., and no effective herbicides are now available for selective control of jointed goatgrass, an increasing weed problem in winter wheat fields in Kansas. The development of a biological herbicide which can selectively control one or more of these problem weeds without affecting winter wheat production would increase the available weed control options, possible reduce weed control costs, and may help protect water quality and the environment. Indigenous bacteria are being isolated from Kansas soils and the rhizosphere of quality and the environment. Indigenous bacteria are being isolated from Kansas soils and the rhizosphere of several crop and weed species and evaluated for selective inhibition of several of these problem weeds. Initial screenings of over 500 isolates in laboratory bioassays have identified 105 isolates which inhibit downy brome root elongation at least 30% without significantly affecting wheat. Almost 40 of these isolates reduce brome root growth over 70%. Sixty-five isolates have reduced Japanese brome root growth by at least 30%, whereas 42 of these isolates inhibit both downy brome and Japanese brome root elongation without affecting winter wheat. Bioassays are currently being run to assess the effects of these bacteria on jointed goatgrass. Also, promising isolates are being evaluated in growth chamber and field studies. If bacterial isolates are discovered which control economically important weeds in major cropping systems, these new biological control mechanisms may become a powerful alternative or addition to a traditional weed control program.