Developing and implementing a sustainable weed management program for herbicide-resistant Poa annua in turfgrass

Authors: MCCURDY, JAMES - Mississippi State University; BOWLING, REBECCA - Texas A&M University; DE CASTRO, EDICARLOS - Mississippi State University; PATTON, AARON - Purdue University; KOWALEWSKI, ALEC - Oregon State University; Mattox, Clint; BROSNAN, JAMES - University Of Tennessee; ERVIN, DAVID - Portland State University; ASKEW, SHAWN - Virginia Polytechnic Institution & State University; GONCALVES, CLEBSON - University Of California; ELMORE, MATTHEW - Rutgers University; MCELROY, SCOTT - Auburn University; MCNALLY, BRANDON - Purdue University; PRITCHARD, BENJAMIN - University Of Tennessee; KAMINSKI, JOHN - Pennsylvania State University; BAGAVATHIANNAN, MUTHUKUMAR - Texas A&M University

Submitted to: Crop, Forage & Turfgrass Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2023
Publication Date: 3/29/2023
Citation: McCurdy, J.D., Bowling, R.G., de Castro, E.B., Patton, A.J., Kowalewski, A.R., Mattox, C.M., Brosnan, J.T., Ervin, D.E., Askew, S.D., Goncalves, C.G., Elmore, M.T., McElroy, S.J., McNally, B.C., Pritchard, B.D., Kaminski, J.E., Bagavathiannan, M.V. 2023. Developing and implementing a sustainable weed management program for herbicide-resistant Poa annua in turfgrass. Crop, Forage & Turfgrass Management. 9(1). Article e20225. https://doi.org/10.1002/cft2.20225.
DOI: https://doi.org/10.1002/cft2.20225

Interpretive Summary: This is the second part of a two-part management guide focusing on integrated weed management of annual bluegrass (Poa annua L.) in turfgrass systems. This paper provides the reader with an overview of how herbicides work, how resistance to herbicide occurs, and how plants are screened for herbicide resistance. A summary of an annual bluegrass resistance survey in the United States is described, followed by a description on how to build an integrated weed management plan to suppress resistant annual bluegrass populations. A table is included that summarizes preemergent and post emergent herbicide efficacy on annual bluegrass safety in cool and warm season turfgrass systems.

Technical Abstract: The ability of Poa annua L. to adapt to most turfgrass environments extends to its adaptation to most known herbicides. Herbicide resistant Poa annua is of almost epidemic proportions. The loss of once viable treatments pushes practitioners towards more expensive, and often less effective, control strategies. Our first paper focuses on ecology, biology, and integrated weed management (IWM) practices for Poa annua control. In this second paper, we focus on herbicide resistance—what it is and how to overcome it. We also discuss resistance mechanisms and document common occurrences of field-level resistance within much of the United States. Finally, we analyze some of the social and economic constraints that practitioners face in the implementation of IWM strategies for Poa annua.