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

Oreja, F.H., D.J. Lyon, J. Gourlie, H.C. Wetzel, and J. Barroso. 2023. Russian thistle (Salsola tragus) post-harvest control and plant dispersal. Weed Technol.

Savic, M., M.E. Thorne, and D.J. Lyon. 2023. Smooth scouringrush (Equisetum laevigatum) control with glyphosate is affected by surfactant choice and application time. Weed Technol.

Lyon, D.J., and M.E. Thorne. 2023. Rush skeletonweed (Chondrilla juncea) control and winter wheat injury with picloram applied in fallow. Weed Technol. 37:296-302.

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. 78:4728-4740.

Lyon, D.J., and M.E. Thorne. 2022. Smooth scouringrush (Equisetum laevigatum) control with glyphosate in Eastern Washington. Weed Technol. 36:457-461.

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).

Timely Topics

Volunteer Wheat Control

This summer has seen a little more rain than usual for many parts of Eastern Washington. Unlike spring showers that bring May flowers, these summer rains are likely to sprout volunteer wheat in your fields. Volunteer wheat acts as a “green bridge” that allows various insects and diseases to survive from one season’s wheat crop to the next. Volunteer wheat within a half-mile of a field that will be planted to wheat should be completely dead at least two weeks before wheat planting.

Step-By-Step Guide for Conducting a Bioassay to Assess Herbicide Carryover Risk

I recently attended wheat variety plot tours near Rearden and Almira to speak about good stewardship practices for CoAXium wheat. Growers at both locations asked me about how long they needed to wait to plant a non-Clearfield wheat variety after several years of using Beyond® herbicide for the control of jointed goatgrass, downy brome, or feral rye. The simple answer can be found on the Beyond label.

Canola to the Rescue

Italian ryegrass is the bane of many Palouse-region farming operations. It is the “poster child” for herbicide resistance. The heavy reliance on a narrow range of herbicides labeled in wheat has resulted in the development of Italian ryegrass populations resistant to many of the herbicides previously used in wheat to control Italian ryegrass, such as the ACCase inhibitors (Group 1), ALS inhibitors (Group 2), and very long-chain fatty acid synthesis inhibitors (Group 15).

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.

Weeders of the West

Crop Competition Is Critical for Weed Control

In the hundreds of herbicide field studies I have conducted since I was a graduate student at the University of Nebraska in the 1980s, herbicides have always performed better in a good stand of a vigorously growing crop than in a poor crop stand. When the topic is weed control, we often focus on what herbicide or herbicides are the best option. Often lost in the discussion of weed control is the importance of growing a competitive crop.

Is No-Till Sustainable?

In my mind, the purpose of a blog is to throw out ideas and have them discussed. With that objective in mind, I would like to discuss the sustainability of no-till annual cropping systems.

I attended my first no-till conference in 1990, the year I started my job as an assistant professor and Extension Dryland Cropping Systems Specialist at the University of Nebraska-Lincoln Panhandle Research and Extension Center in Scottsbluff. I had received my Ph.D. in Agronomy/Weed Science from the University of Nebraska-Lincoln in August of 1988. After a 13-month stint as a Technical Services Representative for American Cyanamid Company in Michigan, I started my job in Scottsbluff. As a weed science graduate student, I had not attended any no-till conferences, but in my new dryland cropping systems position, I thought it was important for me to attend these conferences and see what I could learn. So, in the summer of 1990, I attended the Great Plains No-Till Conference in Bismarck, ND.

Herbicides Are NOT The Solution

Many growers are looking to the agricultural chemical and seed industries for solutions to herbicide resistance in weeds. While I do not have a crystal ball, my understanding of the problem tells me that herbicides are not the solution for herbicide-resistant weeds. Herbicides, just like antibiotics (see this great video titled, The Evolution of Bacteria on a “Mega-Plate” Petri Dish (Kishony Lab), on antibiotic resistance from Harvard Medical School), insecticides, and fungicides, all become less effective with use. Over time, their use selects for individuals (biotypes) that are more tolerant or resistant to them. While practices like rotating and mixing herbicide mechanisms of action can delay the development of herbicides resistance, it does not eliminate the selection of resistant biotypes. The only effective long-term solution to the problem of herbicide resistance is to use less herbicides, not more herbicides.

HWSC in the Pacific Northwest