Weed-suppressive bacteria studies provide little evidence of effectiveness

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Collectively, these studies show that the Weed-Suppressive Bacteria P. flourescens — strains ACK55, D7, and MB906 — are not likely to be effective in controlling invasive exotic grasses in western U.S. rangelands. There were no negative effects to exotic annual grasses, perennial bunchgrasses, or total community cover within three or four years of treatment when WSB was applied in the field alone or in combination with herbicides. It is possible that new formulations or application techniques could lead to more consistent, desired effects; however the studies described above tested three strains across a wide range of conditions, and yet no consistent effects were observed.