Drew Lyon

Drew Lyon

Professor, Endowed Chair Small Grains Extension and Research, Weed Science  (509) 335-2961 259 Clark Hall PO Box 646420, Pullman, WA 99164

Curriculum vitae (pdf)


Ph.D.,  Agronomy/Weed Science, University of Nebraska-Lincoln. August 1988
Dissertation: A search for metribuzin tolerance in fieldbeans (Phaseolus vulgaris).

M.S., Agronomy/Weed Science, University of Nebraska-Lincoln. December 1985
Thesis: Response of fieldbeans (Phaseolus vulgaris) to reduced rates of 2,4-D and dicamba.

B.S., Agronomy/Crop Protection, University of Illinois at Urbana-Champaign. August 1980


My Extension and Research Program focuses on integrated weed management in dryland small grain production in eastern Washington. I will focus on the troublesome weeds in each of the three rainfall zones of eastern Washington, i.e., low, medium, and high. This will include the winter annual grass weeds such as downy brome (Bromus tectorum), jointed goatgrass (Aegilops cylindrica), feral rye (Secale cereale), Italian ryegrass (Lolium multiflorum), and rattail fescue (Vulpia myuros); as well as some of the troublesome warm-season broadleaf weeds in small grains and/or fallow such as mayweed chamomile (Anthemis cotula), Russian-thistle (Salsola tragus), prickly lettuce (Lactuca serriola), rush skeletonweed (Chondrilla juncea), and smooth scouringrush (Equisetum laevigatum). The use of herbicides in conjunction with cultural practices such as crop rotation, plant population, row spacing, and fertility will be investigated as will the use tillage, when necessary. Herbicide-resistant weeds are a major concern in the region and integrated weed management strategies must be devised to deal with existing herbicide resistance issues and slow the development of new herbicide-resistant biotypes. As part of my Extension appointment, I provide leadership for the WSU Extension Dryland Cropping Systems Team. One of our major projects has been the development of the Wheat and Small Grains Website, where growers and consultants can find all the information and decision tools that WSU Extension has related to wheat and small grains production and marketing. I also serve as the host of the WSU Wheat Beat Podcast where I talk with WSU faculty, postdocs, graduate students and USDA-ARS scientists about their wheat-related research.

Associates in Research

Mark Thorne

Recent Publications

Spring, J.F, S.R. Revolinski, F.L. Young, D.J. Lyon, and I.C. Burke. 2022. Weak population differentiation and high diversity in Salsola tragus in the inland Pacific Northwest, USA. Pest Manag. Sci. Advance online publication.

Lyon, D.J., and M.E. Thorne. 2022. Smooth scouringrush (Equisetum laevigatum) control with glyphosate in Eastern Washington. Weed Technol. Advance online publication.

Thorne, M.E., and D.J. Lyon. 2022. Rush skeletonweed (Chondrilla juncea L.) control in fallow. Weed Technol. 35:1045-1051.

Adjesiwor, A.T., D.J. Lyon, J. Barroso, and J.M. Campbell. 2022. Integrated management of wild oat in the Pacific Northwest. (PNW759).

San Martin, C., M.E. Thorne, J.A. Gourlie, D.J. Lyon, and J. Barroso. 2021. Seed retention of grass weeds at wheat harvest in the Pacific Northwest. Weed Sci. 69:238-246.

Gill, K.S., N. Kumar, H.S. Randhawa, K. Murphy, A.H. Carter, C.F. Morris, R.W. Higginbotham, D.A. Engle, S.O. Guy, D.J. Lyon, T.D. Murray, X.M. Chen, and W.F. Schillinger. 2021. Registration of ‘Resilience CL+’ soft white winter wheat. J. Plant Registr. 15:196-205.

Lyon, D.J., J. Barroso, M.E. Thorne, J. Gourlie, and L.K. Lutcher. 2021. Russian-thistle (Salsola tragus L.) control with soil-active herbicides in no-till fallow. Weed Technol. 35:547-553.

Lyon, D.J., J. Barroso, J.M. Campbell, D. Finkelnburg, and I.C. Burke. 2020. Best management practices for managing herbicide resistance. (PNW754).

Fischer, J.W., M.E. Thorne, and D.J. Lyon. 2020. Weed-sensing technology modifies fallow control of rush skeletonweed (Chondrilla juncea). Weed Technol. 34:857-862.

Gill, K.S., N. Kumar, H.S. Randhawa, A.H. Carter, J. Yenish, C.F. Morris, B.-K Baik, R.W. Higginbotham, S.O. Guy, D.A. Engle, X.M. Chen, T.D. Murray, and D.J. Lyon. 2020. Registration of ‘Curiosity CL+’ soft white winter wheat. J. Plant Registr. 14:377-387.

Beres, B.L., J.L. Hatfield, J.A. Kirkegaard, S.D. Eigenbrode, W.L. Pan, R.P. Lollato, J.R. Hunt, S. Strydhorst, K. Porker, D. Lyon, J. Ransom, and J. Wiersma. 2020. Toward a better understanding of genotype x environment x management interactions – A global wheat initiative agronomic research strategy. Front. Plant Sci.

Gill, K.S., N. Kumar, H.S. Randhawa, A.H. Carter, J. Yenish, C.F. Morris, B.-K Baik, R.W. Higginbotham, S.O. Guy, D.A. Engle, X.M. Chen, T.D. Murray, and D. Lyon. 2020. Registration of ‘Mela CL+’ soft white winter wheat. J. Plant Registr. 14:144-152.

Lyon, D.J., A.G. Hulting, J. Barroso, and J.M. Campbell. 2020. Integrated management of downy brome in winter wheat. (PNW668 revision).

Lyon, D. J., A.G. Hulting, J. Barroso, and J.M. Campbell. 2020. Integrated management of feral rye in winter wheat (PNW660 revision).

Lyon, D.J., M.E. Thorne, P. Jha, V. Kumar, and T. Waters. 2019. Volunteer buckwheat control in wheat. Crop Forage Turfgrass Manage. doi:10.2134/cftm2019.05.0033.

Barroso, J., D.J. Lyon, and T. Prather. 2019. Russian thistle management in a wheat-fallow crop rotation. (PNW492).

Lyon, D.J, M.E. Swanson, F.L. Young, and T. Coffey. 2018. Jointed goatgrass biomass and spikelet production increases in no-till winter wheat. Crop Forage Turfgrass Manage. doi:10.2134/cftm2018.04.0031.

Mallory-Smith, C., A.R. Kniss, D.J. Lyon, and R.S. Zemetra. 2018. Jointed goatgrass (Aegilops cylindrica): A review. Weed Sci. 66:562-573.

Walsh, M.J., J.C. Broster, L.M. Schwartz-Lazaro, J.K. Norsworthy, A.S. Davis, B.D. Tidemann, H.J. Beckie, D.J. Lyon, N. Soni, P. Neve, and M.V. Bagavathiannan. 2018. Opportunities and challenges for harvest weed seed control in global cropping systems. Pest Manag. Sci. 74:2235-2245.

San Martín, C., D.J. Lyon, J. Gourlie, H.C. Wetzel, and J. Barroso. 2018. Weed control with bicyclopyrone + bromoxynil in wheat. Crop Forage Turfgrass Manage. 4:180011. doi:10.2134/cftm2018.02.0011.

Spring, J.F., M.E. Thorne, I.C. Burke, and D.J. Lyon. 2018. Rush skeletonweed (Chondrilla juncea) control in Pacific Northwest winter wheat. Weed Technol. 32:360-363.

Hauvermale, A.L., K.N. Race, N.C. Lawrence, L. Koby, D.J. Lyon, and I.C. Burke. 2018. A mayweed chamomile growing degree day model for the Inland Pacific Northwest. (FS306E).

Lyon, D.J., D.A. Ball, and A.G. Hulting. 2018. Rattail fescue: Biology and management in Pacific Northwest wheat cropping systems. (PNW613).

Lyon, D.J., I.C. Burke, and J.M. Campbell. 2018. Integrated management of mustard species in wheat production systems. (PNW703).

Timely Topics

Is That Wheat or a Field of Cheatgrass?

What happened? Wheat fields throughout Eastern Washington are full of downy brome (a.k.a cheatgrass). Many of those that aren’t, are full of Italian ryegrass. Why didn’t herbicides perform better than they did this year? Was it the weather, late applications, or are herbicide-resistant weed biotypes more prevalent than before? We would like to know the answer.

Wheat Harvest and Weeds

Wheat harvest is underway in Eastern Washington. With cool spring weather and ample spring rainfall, it looks like it will be a bountiful harvest. Understandably, growers will be focused on getting their grain out of the field and into the bin, but this is also a good time to think about weeds – I’m always thinking about weeds.

In Days of Yore

In the 1990s, when I was beginning my academic career at the University of Nebraska-Lincoln Panhandle Research and Extension Center in Scottsbluff, Monsanto still held the patent for glyphosate, and it could only be purchased in the US as Roundup herbicide. It sold for about $90/gallon, which in today’s dollars would be about $180/gallon. Needless to say, growers were not interested in applying a quart or two per acre in the 1990s. In fact, many growers did not want to apply even the labeled rate of 16 oz/acre. They were always asking “How low can I go?” It is a question that is once again being asked as glyphosate supply dwindles and prices skyrocket.

Weeders of the West

The Reemergence of Preemergence Herbicides

Posted by Drew Lyon | June 1, 2022

Since the introduction of Roundup Ready crops in the mid- to late-1990s, postemergence herbicides have played an increasing role in weed control for many crops including corn, soybean, cotton, and wheat. The introduction of Maverick herbicide (now sold as Outrider) in 2001 changed how wheat growers managed downy brome (a.k.a. cheatgrass) and other annual brome species in wheat. Maverick (now Outrider), and subsequently several other ALS-inhibiting herbicides including Osprey, Olympus, and PowerFlex HL, selectively control downy brome and other annual grass weeds in wheat. Growers quickly abandoned the use of preemergence herbicides, with their variable use rates dependent on soil type and their efficacy often dependent on timely rain, for the convenience and reliability of postemergence herbicides. However, our overuse of these products has resulted in widespread herbicide resistance to many postemergence herbicides.

I Can’t Say This Enough!

Posted by Drew Lyon | January 13, 2022

When it comes to delaying the development of herbicide resistance in weeds, herbicide mixing and rotation are critical. In an earlier blog post titled, “Two Are Better Than One”, I spoke about the strong benefits of mixing herbicide mechanisms of action. I noted that one of the 12 Best Management Practices (BMPs) for reducing the risks of herbicide resistance is:

Use multiple, effective MOAs (Mechanisms of Action) against the most troublesome weeds and those prone to herbicide resistance.