WERA_OLD77: Managing Invasive Weeds in Wheat

(Multistate Research Coordinating Committee and Information Exchange Group)

Status: Inactive/Terminating

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SAES-422 Reports

Annual/Termination Reports:

[05/19/2015] [05/10/2016] [05/05/2017] [05/05/2017] [05/08/2018] [05/10/2019]

Date of Annual Report: 05/19/2015

Report Information

Annual Meeting Dates: 03/12/2015 - 03/12/2015
Period the Report Covers: 10/01/2013 - 09/01/2014

Participants

Barroso, Judit (judit.barroso@oregonstate.edu)- Oregon State University;
Burke, Ian (icburke@wsu.edu)- Washington State University;
Campbell, Joan (jcampbell@uidaho.edu)- University of Idaho;
Fransen, Kyle (kfrandsen@uidaho.edu)- University of Idaho;
Kniss, Andrew (akniss@uwyo.edu)- University of Wyoming;
Lehnhof, Erik (erik.lehnhoff@montana.edu)- Montana State University;
Lyon, Drew (drew.lyon@wsu.edu)- Washington State University;
Mallory-Smith, Carol (carol.mallory-smith@oregonstate.edu)- Oregon State University;
Neely, Clark (cneely@ag.tamu.edu)- Texas A&M University;
Peterson, Dallas (dpeterso@ksu.edu)- Kansas State University;
Post, Angela (angela.post@okstate.edu)- Oklahoma State University;
Rapp, Ryan (ryan.e.rapp@monsanto.com)-Monsanto;
Roerig, Kyle (kyle.roerig@oregonstate.edu)- Oregon State University;
Thill, Donn (dthill@uidaho.edu)- University of Idaho;

Brief Summary of Minutes

Don Morishita – chair (not present)

Joan Campbell (secretary) called the meeting to order at 1 pm

Attendance sheet was passed around the room and attendees introduced themselves. Two members participated by telephone.

NIMSS Update - Donn Thill, Administrative Advisory. WERA077 is in good shape and goes through October 30, 2019. Internal review will be in the third year. Timely submission of impact statements for activities was stressed.

The seeding direction study was the first item of discussion. The following data will be collected in Texas; Kimberly and Moscow, Idaho; Pendleton and Corvallis, Oregon; Washington; Kansas and Oklahoma:

1. Weed density, counts taken as necessary to capture variability of the stand, report as plants per square meter

2. Wheat stand, counts taken as necessary to capture variability of the stand, report as plants per m of row

3. Weed height, 10 random measures at weed head emergence

4. Weed biomass, take biomass measure to capture variability of the stand, report as g per square meter (this is taken at same time as weed height)

5. Weed seed production, collect seed to capture variability of the stand, reported as number per square meter.

6. Send seed to Ian Burke for genotype

7. Wheat height, canopy height taken at crop flag leaf stage of growth

8. Wheat yield (kg per ha) and test weight

9. Send all data to Andrew Kniss. Make certain all data is reported as requested. Include number of replications.

10. Optional data to include a photo and/or light reading: Place a meter stick on the ground in the plot to photograph each experimental unit at the same distance above ground. (The two edges of the meter stick should be just within view). Take photo at dawn or under cloud cover to minimize shadows.

11. If weeds are not present, report information on wheat only as that is important information as well.

Publication of combined pyroxasulfone data was the second discussion item. The article will be written after all data is statistically analyzed. Andrew Kniss will prepare a spread sheet and analyze data. Please fill in accurately as requested. Lead writers have yet to be determined.

The third item of discussion was on feral rye (aka common, cereal, winter, or volunteer rye) Secale cereale L.

Feral rye typically matures and shatters before wheat harvest. It has been reported to reduce winter wheat yield

Data to collect:

Seed will be collected to be grown in common gardens representing eco-climatic areas from north to south and east to west. Collect 1 liter of seed for each individual site. The number of sites to include in the common gardens and the number of common gardens are to be determined in the future (likely five or six sites). Seed not included in the common garden might still be included in genotyping. Seed should be threshed, cleaned, dried and stored in a closed container. All seed will be stored at a single site.

Possible common garden sites:

Texas/Oklahoma/Kansas

Montana

Wyoming

Southern Idaho/Pendleton/Central Washington

Willamette Valley

Northern Idaho

The meeting concluded with state reports.

No nominations were put forward for secretary. Don Morishita will continue as chair and Joan Campbell will continue as secretary.

Meeting adjourned at 3:15 pm

Accomplishments

Seeding direction study was established in Pendleton, OR; Moscow, ID; Kimberly, ID; Wyoming; Utah; and Montana with downy brome and Corvallis, OR; Oklahoma; and Texas with Italian ryegrass. Procedures and experiments for feral rye seed collection summer 2015 from Montana, Utah, Idaho, Washington, Texas, Kansas, and Oregon and planting of common gardens were outlined. Feral rye typically matures and shatters before wheat harvest. It has been reported to reduce winter wheat yield 14 to 69% in population from 5 to 18 plants per square meter, respectively. Feral rye may cause dockage, grade reduction and a loss of wheat quality. Wheat flour contaminated with rye has poor baking characteristics. Few control measures are available for good control of feral rye in wheat. It is a widespread weed, but it is not a real problem in certain areas. Feral rye has been reported to be moving upslope in south facing, non-arable, gravel steep slopes. With climate change, does feral rye have the potential to increase? Various lots of feral rye have been introduced at different times throughout the region. Are populations of feral rye from Texas to Montana and west to Washington and Oregon homogenous? In addition, feral rye has been present long enough to have some selection due to geographical area. The potential of changing climate on plant species is relevant in relation to Growing Degree Days and moisture response. Seed will be collected from geographical diverse areas, grown in common gardens, and will be genotyped.

Publications

Lawrence, N and I C Burke. 2014. Control of rattail fescue (Vulpia myuros) in no-till winter wheat. Weed Technol. 28:471-478. Lyon, D.J., A.G. Hulting, D.W. Morishita, and F.L. Young. 2014. Integrated management of downy brome in winter wheat. Pacific Northwest Extension Publication 668 (PNW668). Washington State University, Pullman, WA.

Impact Statements

Confirmed dicamba-resistance in kochia, the explosive increase of glyphosate resistance in Palmer amaranth, and confirmed multiple herbicide resistance in kochia complicates and increases weed management costs. Increased use of tillage in place of herbicides to control herbicide resistant weed populations threatens gains in soil and water conservation.
Determined the tolerance and efficacy of newly registered and soon-to-be registered herbicides, which is critical to the development of unbiased information on the use of these products by wheat growers for specific growing regions. This data assists in timely federal registration of new herbicides for control of weeds that threaten western wheat production. Herbicides with new and different modes of action can reduce or stop the development of herbicide resistant weeds. Craze herbicide may be an option for possible control of herbicide resistant broadleaf weeds.
Zidua (Group 15) was registered for annual grass control, including Italian ryegrass and rattail fescue, in winter and spring wheat in spring 2014. Zidua registration will aid in control of Group 1 and 2 resistant Italian ryegrass. Very few other herbicides control rattail fescue. These registrations provide needed tools to help control herbicide resistant weeds.
Knowledge of cultural controls, crop rotation and tillage, are limited for rattail fescue control. Current information is speculative at best. Herbicide usage in winter wheat is the only known research-based tool for rattail fescue control. Data collected on cultural controls will help growers take an integrated weed management approach to reducing rattail fescue.
Valor and Spartan may control common broadleaf weeds in legume crops. Concern is that these herbicides may persist in the soil and cause injury and yield reduction in winter wheat. Studies show that Valor and Spartan may be safely used in pea and chickpea crops without reducing yield in winter wheat, which increased herbicide choices to control devastating broadleaf weeds in legume crops where crop competition is limited and herbicide options are few.

Date of Annual Report: 05/10/2016

Report Information

Annual Meeting Dates: 03/10/2016 - 03/10/2016
Period the Report Covers: 10/01/2015 - 09/30/2016

Participants

Barroso, Judit (judit.barroso@oregonstate.edu) – Oregon State University;
Burke, Ian (icburke@wsu.edu) – Washington State University;
Campbell, Joan (jcampbel@uidaho.edu) – University of Idaho;
Carl Coburn (ccoburn2@uwyo.edu) – University of Wyoming;
Jugulam, Mithila (mithila@ksu.edu) – Kansas State University;
Hulting, Andy (Andrew.hulting@oregonstate.edu) – Oregon State University;
Kniss, Andrew (akniss@uwyo.edu) – University of Wyoming;
Lehnhoff, Erik (erik.lehnhoff@montana.edu) – Montana State University;
Lyon, Drew (drew.lyon@wsu.edu) – Washington State University;
Fabian Menalled (menalled@montana.edu – Montana State University;
Don Morishita (don@uidaho.edu; –University of Idaho;
Neely, Clark (cbn108@tamu.edu) – Texas A&M University;
Roerig, Kyle (kyle.roerig@oregonstate.edu) – Oregon State University;
Ransom, Corey (corey.ransom@usu.edu) – Utah State University;
Traci Rauch (trauch@uidaho.edu) – University of Idaho;
Phil Westra (cows19@comcast.net) – Colorado State University;

Brief Summary of Minutes

Don Morishita, chair, called the meeting to order at 12:30 pm. Attendance sheet was passed and attendees introduced themselves. One member participated by telephone. The seeding direction study was the first item of discussion. No one site on its own had statistically significant differences. Andrew Kniss is combining all sites together which may provide useful information. The second item of discussion was on feral rye. Seed was collected from four sites in 2015 and additional sites will be collected in 2016. Seed will be grown in common gardens representing eco-climatic areas from north to south and east to west. The details of the common gardens are to be determined by a sub-committee of Joan Campbell and Ian Burke. Seed not included in the common garden will be included in genotyping. All seed should be sent to Joan Campbell for storage at a single site. Two participants will run germination experiments on a temperature gradient plate to determine optimum germination. The third item of discussion was potential grant proposals. This will continue at the next meeting due to time constraints. Erik Lehnhoff was elected secretary. Joan Campbell will serve as chair. The next meeting will be held March 13, 2017 before the Western Society of Weed Science meeting in Coeur d’Alene, Idaho. Meeting adjourned at 2:30 pm

Minutes Attachment:

WERA077 2016 report.docx

Accomplishments

Zidua (group 15) was registered for annual grass control, including Italian ryegrass and rattail fescue, in winter and spring wheat in spring 2014. Zidua registration will aid in control of group 1 and 2 resistant Italian ryegrass. Very few herbicides control rattail fescue. Zidua and Anthem treatments controlled rattail fescue 82-98% in 2015.Winter wheat was not injured by Zidua under irrigation (worst-case scenario). Wheat had less than 5% injury in six conventional-tilled (chisel plowed/field cultivated) sites and in two direct-seed locations. These studies were instrumental in implementing Zidua label changes including earlier application time and increased use rate. These label changes will aid growers by giving them more options to improve weed efficacy. Anthem Flex also was registered in wheat fall 2014. Anthem Flex studies were useful to FMC when drafting rates and timings for the federal label. All of this information will help growers use these products safely and effectively to control grass weeds with minimal crop injury. These registrations provide needed tools to help control herbicide resistant weeds. Knowledge of cultural controls, crop rotation and tillage is limited for rattail fescue control. Current information is speculative at best. Herbicide usage is the only known research-based tool for rattail fescue control. In 2015 tillage studies, rattail population was highest in no-till and least in chisel treatments. At one location, chisel, disc, and no-till plots yielded 3582, 3137, and 2926 lb/A, respectively. This data will help growers take an integrated weed management approach to reducing rattail fescue and increasing crop yield. Suspected-resistant weed seed samples collected from research plots and submitted by Idaho growers, fieldmen, and industry representatives were screened in the greenhouse. No sample screened was resistant to pyroxaslufone, metolachlor, flufenacet, clethodim or glyphosate. Samples were resistant to Amber, Osprey, and PowerFlex (group 2) and Poast, Assure II and Axial XL (group 1).Screening weed seed samples enables growers to combat herbicide resistance by adjusting their weed control approach so that it includes rotating chemicals, changing crop rotations, and implementing other cultural practices. Grower and industry awareness of herbicide resistance in Italian ryegrass, downy brome, and Russian-thistle was increased through a series of winter meeting presentations in Washington, an article in Wheat Life magazine, and Timely Topic posts on the Wheat and Small Grains Website (smallgrains.wsu.edu). Collaborated with the Richland County Extension Agents to identify two biotypes of Conyza canadiensis resistant to glyphosate. This represents a new case of herbicide resistance in Montana. Collaborated in the publication of three educational videos ‘Enzyme linked immunosorbent assay video’. https://vimeo.com/117442610 (password: plantvirus) ‘Francis the farmer’ animation for WSMV education. <a href="https://vimeo.com/124056111">https://vimeo.com/124056111</a>. ‘MSU organic farming study finds diverse benefits’ https://www.youtube.com/watch?v=Y5w25UgWMTs&feature=youtu.be Developed and delivered a total of 29 extension/outreach presentation at 12 locations across Montana. Invited out of state and international extension presentations included one presentation in South Dakota and two presentations in Ontario, Canada. California. Also, presented two webinars organized by eOrganic and National Association of County Agricultural Agents. Over 1,400 participants were directly reached in these presentations. Studies in western Oregon focus on grass control in winter and spring wheat.  Control of Italian ryegrass, California brome, downy brome and rattail fescue in winter wheat are being evaluated with a range of preemergence, early postemergence and postemergence applications of herbicides in several studies. Data from these trials are used to support labeling of herbicides in diverse wheat-cropping systems in Oregon. Research and experience using recently registered products provides critical information to growers and agri-business consultants that allow them to refine their weed control practices, control invasive weeds efficiently, and avoid wheat injury and yield reductions. The research is also critical to aiding the early adoption of new technologies in wheat production which maintains the competitiveness of Oregon wheat production. Weed management Extension presentations were made to wheat producers in many Oregon locations including Forest Grove, Albany, Salem, Mt. Angel, Corvallis, Klamath Falls, Pendleton, Condon, Hood River, LaGrande, and Walla Walla, WA, among other locations throughout Oregon and the Pacific Northwest.  Topics covered included precision application of herbicides for weed management, herbicide resistance management, herbicide mode of action, Russian thistle control, carryover potential for Beyond herbicide in wheat, and Italian ryegrass, rattail fescue and downy brome control in winter and spring wheat.  Formal field tours or research results were conducted with industry groups and growers at the Columbia Basin Ag Research Center in Pendleton, the Hyslop Ag Research Farm near Corvallis and in Washington County.  Andrew Hulting continues to serve as Associate Editor for the PNW Weed Management Handbook and edit and update several wheat-related weed management chapters in the handbook on a yearly basis: <a href="http://pnwhandbooks.org/weed/">http://pnwhandbooks.org/weed/</a>.

Publications

Barroso, J, Miller Z., Lehnhoff, EA, Hatfield, PG, and Menalled, FD. 2015. Impacts of cropping system and management practices on the assembly of weed communities. Weed Research, 55:426-435   Young, F. L., D. K. Whaley, N. C. Lawrence, and I. C. Burke. 2016. Feral rye (Secale cereale) control in winter wheat in the Pacific Northwest. Weed Technol. 30:163-170.   Lyon, D.J., D.R. Huggins, and J.F. Spring. 2016. Windrow burning eliminates Italian ryegrass (Lolium perenne ssp. multiflorum) seed viability. Weed Technol. 30:279-283.   Raeder, A. J., D. Lyon, J. Harsh, and I. C. Burke. 2015. How soil pH affects the activity and persistence of herbicides. Washington State University. FS189E. Lyon, D.J, and I.C. Burke. 2016. Integrated management of prickly lettuce in wheat production systems. Washington State University. PNW 688. Varanasi VK, Godar AS, Shoup D, Peterson DE and Jugulam M. 2016. A Target-Site Point Mutation in Henbit (Lamium amplexicaule L.) Conferring High Level Resistance to ALS-Inhibitors. Weed Science. 64: 231-239. (KAES # 16-041-J). Jugulam M, Ziauddin A, So KKY, Chen S and Hall JC. 2015. Transfer of dicamba tolerance from Sinapis arvensis to Bassica napus via embryo rescue and recurrent bbackcross breeding. PLoS ONE 10(11): e0141418. doi:10.1371/journal.pone.0141418 (KAES # 15-098-J). Godar AS, Varanasi VK, Betha S, Prasad PVV, Thompson CR and Mithila J. 2015. Physiological, biochemical and molecular mechanisms of differential sensitivity of Palmer amaranth to mesotrione at varying temperatures. PLoS ONE 10(5): e0126731. doi:10.1371/journal. pone.0126731. Varanasi VK, Godar AS, Currie RS, Dille JA, Thompson CR, Stahlman PW and Jugulam M. 2015. Field evolved resistance to four modes of action of herbicides in a single kochia (Kochia scoparia Schrad) population. Pest Management Science. doi: 10.1002/ps.4034. Chatham LA, Bradley KW, Kruger GR, Martin JR, Micheal JR, Owen DK, Peterson DE, Mithila J and Tranel PJ. 2015. A multi-state study of the association between glyphosate resistance and EPSPS gene amplification in waterhemp (Amaranthus tuberculatus). Weed Science 63: 569-577 Godar AS, Stahlman PW, Jugulam M and Dille JA. 2015. Glyphosate-resistant Kochia in Kansas: EPSPS gene copy number in relation to resistance levels. Weed Science: 63: 587-595. Peterson DE, Thompson CR, Shoup DE and Jugulam M. 2015. Mode of action of herbicides. KSRE Publication #C715 (<a href="http://www.bookstore.ksre.ksu.edu/pubs/C715.pdf).%3cp">http://www.bookstore.ksre.ksu.edu/pubs/C715.pdf).<p</a>> Vipan Kumar, Prashant Jha, Darci Giacomini, Eric P. Westra, and Philip Westra (2015) Molecular Basis of Evolved Resistance to Glyphosate and Acetolactate Synthase-Inhibitor Herbicides in Kochia (Kochia scoparia) Accessions from Montana. Weed Science: October-December 2015, Vol. 63, No. 4, pp. 758-769. Miller Z and Menalled FD  (2015) Impact of species identity and phylogenetic relatedness on biologically-mediated plant-soil feedbacks in a low and a high intensity agroecosystem.   Plant and Soil, 389, 171-183. Keren I, Menalled FD, Weaver D and Robison-Cox J  (2015) Interacting agricultural pest management practices and their effect on crop yield: Application of a Bayesian decision theory approach to the joint management of Bromus tectorum and Cephus cinctus. PLOS ONE, DOI: 10.1371/journal.pone.0118111

Impact Statements

Date of Annual Report: 05/05/2017

Report Information

Annual Meeting Dates: 03/13/2017 - 03/13/2017
Period the Report Covers: 10/01/2015 - 09/30/2016

Participants

Barroso, Judit (judit.barroso@oregonstate.edu) – Oregon State University
Burke, Ian (icburke@wsu.edu) – Washington State University
Campbell, Joan (jcampbel@uidaho.edu) – University of Idaho
Creech, Cody (ccreech@@unl.edu) – University of Nebraska
Crump, Amanda (acrump@ucanr.edu) – Western IPM Center
Hulting, Andy (Andrew.hulting@oregonstate.edu) – Oregon State University
Lawrence, Nevin (nlawrence2@unl.edu) - University of Nebraska
Lehnhoff, Erik (erik.lehnhoff@montana.edu) – New Mexico State University
Lyon, Drew (drew.lyon@wsu.edu) – Washington State University
Manuchehri, Misha (mish.manuchehri@okstate.edu) – Oklahoma State University
Menalled, Fabian (menalled@montana.edu – Montana State University
Morishita, Don (don@uidaho.edu; –University of Idaho
Roerig, Kyle (kyle.roerig@oregonstate.edu) – Oregon State University
Ransom, Corey (corey.ransom@usu.edu) – Utah State University
Rauch, Traci (trauch@uidaho.edu) – University of Idaho
Thompson, Curtis (cthompso@ksu.edu) – Kansas State University

Brief Summary of Minutes

Joan Campbell, chair, called the meeting to order at 3:45 pm. Attendance sheet was passed and attendees introduced themselves. Michael Harrington, executive director of Western Association of Agricultural Experiment Station Directors, attending by phone, gave a Multistate Committee Update and a presentation on the new farm bill.

The seeding direction study was the first item of discussion. Andrew Kniss has combined data from all sites and looked for patterns in seeding direction impacts on downy brome. Site latitude was considered as a co-variate in the models. No obvious patterns of significance were noted; however this may be from the lack of replication (n=4) and the abnormal drought conditions at several sites that may have limited downy brome emergence.

The second item of discussion was on feral rye. Seed was collected from four sites in 2015 and additional three sites in 2016. The seed has not yet been consolidated for use in common gardens. A bew protocol for seed collection will be established for 2017. For every field to be sampled, 5 heads will be collected from 5 plants distributed throughout a field. (Nevin Lawrence will write a protocol and send it to the group.) Seeds will be sent to a single site (TBD), and seed increased at that site to minimize maternal effects. After seed increase, a common garden experiment will be conducted at various sites throughout the range of feral rye representing eco-climatic areas from north to south and east to west. The details of the common gardens are to be determined by a sub-committee of Joan Campbell and Ian Burke. Seed not included in the common garden will be included in genotyping.

The third item of discussion was potential grant proposals. There is a possibility that funding for the feral rye study including understanding feral rye herbicide resistance can come from the Western IPM center. The NIFA CPPM program was also mentioned as a possibility. Andy Hulting will obtain more information and further investigate these possibilities.

Judit Barroso was elected secretary/chair elect. Erik Lehnhoff will serve as chair. The next meeting will be held March 12, 2018, 3:00-5:00 PM before the Western Society of Weed Science meeting in Garden Grove, CA. Meeting adjourned at 5:00 PM.

Accomplishments

IDAHO REPORT Joan Campbell, Research and Instructional Associate; Traci Rauch, Senior Research Specialist; and Don Morishita, Extension Weed Scientist. PSES Dept, University of Idaho, 875 Perimeter Dr. MS 2339, Moscow, ID 83844; 208-885-7730; <a href="mailto:jcampbel@uidaho.edu">jcampbel@uidaho.edu</a> Objective 1. Results: Winter wheat tolerance was evaluated in Zidua formulations with and without irrigation, different rates and timings. A new liquid formulation decreased yield with same day irrigation compared to no irrigation. The same formulation in a non-irrigated study decreased yield at a high vs. low rate at a per-germination timing. No yield difference between rates if wheat was germinated. The second year of Anthem Flex winter wheat variety tolerance trial indicated some injury to Brundage96, but not Boundary, Cara, or Silver. In winter wheat, Italian ryegrass control with Anthem Flex was best with the highest rate at the postplant pre-germinated wheat timing. It was better than the preplant timing most likely due to the shorter time period for activation by rainfall (30 days preplant vs. 11 days postplant). Italian ryegrass control in spring wheat with Anthem Flex showed rate dependent Italian ryegrass control at the preplant timing vs. the germinated wheat timing. Anthem Flex rate and timing evaluations will be continuing in winter and spring wheat. A winter wheat/Italian ryegrass control study evaluated Zidua and Anthem Flex at the highest labeled rates with the following application times:  pre-fertilization (shanked deep band liquid application equipment), post fertilization, postplant no germination and postplant germinated wheat. Italian ryegrass control with both herbicides was improved with less disturbance. The two postplant applications times differed due to time of activation with rainfall. Rain fell 18 days after the non-germinated application versus 3 days after the germinated wheat application. This study is being repeated in 2017. In 3 studies, rattail fescue was controlled 88% or greater with Zidua and Anthem Flex applied postplant preemergence in the fall alone or in combination with spring postemergence applications. Spring applied Everest, PowerFlex, and Maverick only suppressed rattail fescue. These studies will be repeated in 2017. Downy brome was controlled 80% or greater with Zidua, Anthem Flex and PowerFlex HL. Objective 2. Results: A field trial was established at UI research farms near Moscow and Genesee to examine tillage effects on rattail fescue. Winter wheat was direct-seeded in fall 2013. The rotation is winter wheat- spring wheat- spring chickpea. Tillage initiated in the fall 2014 included fall disc or chisel plow followed by spring field cultivation. A no-tillage treatment is included as a control. Heavy harrow will replace disc in year 2 and 3. The tillage is performed all 3 years, 2 years or 1 year for a total of 7 tillage regimes. Spring chickpea was seeded in 2016. Rattail fescue populations were low in the chickpea year of the tillage comparison study. The weed was found only in no-till and the one year of chisel plow. Tillage treatments were applied and winter wheat has been planted this fall for the third year of the study. Objective 3 Results. Two new broadleaf weed control herbicides in winter wheat were evaluated. Talinor (bicyclopyrone/bromoxynil) controlled a heavy mayweed chamomile population 98-99% which was better than Huskie and Starane Flex. Winter wheat yield was greater in the Talinor treatments compared to Widematch. Tarzec (halauxifen/pyroxsulam) controlled catchweed bedstraw 90-98% but did not control mayweed chamomile. A new postemergence grass herbicide, Osprey Xtra (mesosulfuron/thiencarbazone), controlled rattail fescue better than Everest and Osprey. Studies this spring will continue to evaluate these new herbicides for weed control efficacy.  A new stripe rust fungicide (3 active ingredients) was evaluated in combination with different herbicides. The fungicide (at two different rates) combined with PowerFlex, Widematch and MCPA ester reduced yield compared to the check. Another study will be conducted in 2017. Objective 4 Results. Suspected-resistant weed seed samples collected from research plots and submitted by growers, fieldmen, and industry representatives were screened in the greenhouse. The weed seed samples were grown in the greenhouse and sprayed with suspected-resistant and non-resistant herbicides at twice the labeled rate. Susceptible plants were included to verify herbicide spray coverage and rate. Seeds were counted at planting with preemergence herbicides and plants are counted at emergence with postemergence herbicides. Untreated plants were included from each sample. Resistance was evaluated on plant survival and vigor compared to the untreated. In 2015, nine Italian ryegrass seed samples were treated with 12 different herbicides. No sample screened was resistant to Zidua, Dual Magnum, or glyphosate. Samples were resistant to Amber, Everest, Osprey, and PowerFlex (group 2) and Poast, Assure II, Shadow (clethodim) and Axial XL (group 1) and Axiom (group 15 and 5). Four wild oat seed samples were treated with 8 herbicides. No sample was resistant to Shadow, Poast, Beyond, Axial XL, and glyphosate. Samples were resistant to PowerFlex, Osprey (group 2), and Assure II (group 1). Objective 5 Results: Project personnel participated in cereal school meetings in north Idaho in January. Research information was presented at the Western Society of Weed Science regional meeting in March. Wheat system information was presented at International Weed Science Congress in June. Cereal research was also presented at field days in north and south Idaho in June and July.   KANSAS REPORT Kochia has been an economically important broadleaf weed in the US Great Plains including Kansas. However, in the recent years, Palmer amaranth has also become a major problem weed in Kansas. Specifically, evolution of multiple herbicide resistance in kochia and Palmer amaranth, is a serious threat to sustainable crop production. We have confirmed resistance to four modes of action of herbicides in a single kochia population from a crop field near Garden City, and this was reported in last year’s progress report. Additionally, environmental factors such as temperature shown to have significant effect in managing kochia populations with dicamba and glyphosate, commonly used herbicides for kochia management. We recently confirmed resistance to modes of action of herbicides in Palmer amaranth in several Counties in KS. Effect of Growth Temperature on Dicamba and Glyphosate Efficacy in Kochia. Kochia (Kochia Scoparia) is a major problematic weed in United States and Canada. Dicamba and Glyphosate offer effective herbicide options to control kochia. Previous research showed the efficacy of dicamba and glyphosate varied under different environmental conditions, including plant growth temperature. In this study, the effect of growth temperature on efficacy of dicamba and glyphosate in kochia was investigated. Dicamba- and glyphosate- susceptible kochia plants were grown in growth chambers maintained at different temperatures (day/night, °C): low (LT), 17.5/7.5; optimum (OT), 25.0/15.0; and high (HT), 32.5/22.5. When plants reached 8-10 cm tall, they were treated with 0, 1/32, 1/16, 1/8, 1/4, 1/2, 1X rates of dicamba (where X is 560 g·ae·ha-1) or glyphosate (where X is 840 g·ae·ha-1). Visual injury, fresh and dry biomass were recorded 4 weeks after treatment (WAT). Each treatment had 4-6 replications and experiments were done twice. Furthermore, dicamba and glyphosate uptake and translocation experiments were conducted using 6-8 cm tall kochia plants grown under above temperatures. Ten μL of dicamba (3.0 g·ae·L-1) or glyphosate (4.5 g·ae·L-1) containing 20,000 dpm·μL-1 14C radioactivity was applied on two newly matured leaves. At 24, 48 and 72 hours after treatment, the treated leaves (TL) were washed with 20% (v/v) ethanol solution with 0.5% (v/v) Tween-20. Subsequently, the TL, plant tissue above treated leaf (ATL) and below treated leaf (BTL) were harvested, dried and combusted to determine the amount of radioactivity. Results of dicamba dose-response on kochia show the ED50 of xxx, 50.2, 141.9 g·ae·ha-1, at LT, OT and HT, respectively. Whereas, for glyphosate, the ED50 at LT, OT and HT were yy.y, 60.4, and 173.5 g·ae·ha-1, respectively. Analysis of data of uptake and translocation studies indicate that the dicamba is more effective on kochia grown under LT, possibly because of increased translocation compared to plants grown under OT or HT. Similarly, glyphosate was also found more effective on kochia grown under LT than OT or HT. On the contrary, this increased efficacy of glyphosate under LT may be attributed to increased uptake of the herbicide rather than the translocation.   NEW MEXICO REPORT Erik Lehnhoff and Abdel Mesbah, New Mexico State University, Department of Entomology, Plant Pathology, and Weed Science In New Mexico, one study on tank mixing Huskie with broadleaf herbicides for weed management in winter wheat is being conducted in Clovis. Results show improved control of broadleaf weeds including kochia, Russian thistle and pigweed. It is too early in this study to present impacts.   WASHINGTON REPORT Drew J. Lyon and Ian C. Burke Research: Mayweed chamomile control in winter wheat with Talinor. A field study was conducted at the WSU Palouse Conservation Field Station near Pullman, WA to generate broadleaf weed control data with Syngenta’s Talinor herbicide in winter wheat. Talinor is a premixture of bromoxynil (Group 6) and bicyclopyrone (Group 27) herbicides. Talinor is tank mixed with CoAct+™, which is a safener. Huskie® contains pyrasulfotole, which is also a Group 27 herbicide, and bromoxynil, and is why it is used as a comparison treatment against this new active ingredient combination. Talinor alone, Talinor plus the tank mix partners tested, and Huskie alone provided greater control of mayweed chamomile 15 days after application than the Affinity Tankmix and WideMatch treatments. On June 17th, 57 DAT, Talinor treatments exhibited better control of mayweed chamomile than the Huskie treatments. The exception was Talinor + CoAct+ + Axial Star, which provided similar mayweed chamomile control to Huskie at 15 fl oz/A. There did not appear to be a rate response for Talinor treatments like there were with the Huskie treatments. When the final rating was taken on July 5th, 75 DAT, all treatments were providing good to excellent control of mayweed chamomile except Huskie at 11 fl oz/A. Talinor is an effective herbicide for mayweed chamomile control in winter wheat. Rush skeletonweed control in winter wheat following CRP takeout. Rush skeletonweed is a deep-rooted perennial species that has become well established on thousands of acres across eastern Washington while the land was out of wheat production in the Conservation Reserve Program (CRP). Recent changes to the CRP have resulted in many acres coming back into production and most often without prior skeletonweed control. Uncontrolled skeletonweed in the fallow phase of the rotation reduces seed-zone moisture and leaves inadequate soil moisture for germination of winter wheat in the fall. Areas where wheat fails to emerge are either late-seeded after fall rains replenish soil moisture or are left blank. In either case, crop yield is reduced. Herbicide control in the crop phase is one part of an overall strategy to reduce or eradicate skeletonweed from these production areas. We applied five different synthetic auxin herbicides to rush skeletonweed infested winter wheat on November 12, 2015 as the wheat was tillering and again prior to stem jointing on March 17, 2016, at a field site near LaCrosse, WA. In this trial, fall applications of Milestone or Stinger substantially controlled rush skeletonweed in the crop phase of the rotation without reducing grain yield. The experimental DPX-MAT28-128 and 2,4-D LV6 did not control skeletonweed well and appeared to reduce yield. Clarity did not lower yield, but also did not control skeletonweed. Downy brome vernalization and dormancy. Downy brome is arguably one of the worst invasive weed species in both natural and agronomic environments in the United States. Phenological variation is a key factor in the success of the species as a competitor in wheat production regions of the inland Pacific Northwest (PNW). Prior research characterized vernalization and flowering time requirements of downy brome collected from different environments, but no previous work has focused on the connection between such phenotypic responses with the genotypic control of vernalization. A series of common garden experiments was conducted involving 85 accessions of downy brome collected from within small grain production fields of Washington, Oregon, and Idaho. Results of previous common garden experiments identified differences in time to flowering of up to 19 days and time required for mature seed production of up to 21 days among accessions with little variation among siblings. From the common garden experiments cumulative growing degree days required for mature seed production for each accession was estimated using non-linear regression. A series of greenhouse experiments was conducted to characterize the vernalization requirements of downy brome accessions demonstrating differences in development and flowering time, and to determine if differences in expression of VRN1 orthologues is associated with differences in flowering time. Semiquantitative PCR was used to measure VRN1 expression in eight downy brome accessions with different vernalization requirements. Expression of a VRN1 orthologue was only observed in treatments were flowering occurred, suggesting that the molecular controls regulating vernalization and flowering in downy brome are likely conserved with those in related species. To address seed dormancy, research was conducted to explore the central hypotheses that differences in seed dormancy contribute to extensive phenotypic plasticity and adaptability in downy brome in small grain agricultural settings, and dormancy differences are regulated by changes in sensitivity to and signaling of the two plant hormones abscisic acid (ABA; dormancy promoting) and gibberellin (GA; germination stimulating). Phenotypic differences in seed dormancy were measured at physiological maturity utilizing a core collection of downy brome accessions from six population clusters across the dryland cropping areas in PNW (Lawrence and Burke). Seed dormancy and dormancy release were measured through changes in sensitivity to ABA and GA across an after-ripening time course, and in response to dark or light. Our preliminary findings suggest that: 1) at physiological maturity all accessions screened fall into the "dormant" category (0-25% germination) regardless of population cluster, 2) dormancy release occurs as a result of measurable changes in sensitivity to ABA and GA, as well as other environmental cues such as light, and 3) there are at least 4 distinct dormancy scenarios that exist among downy brome accessions which may not be associated with population cluster. Herbicide resistance screening of downy brome. We have established a herbicide resistance screening program. To date, initial screens for 34 individual biotypes from a total of 13 locations across the states of Washington and Oregon have been completed. With the implementation of new methods including the addition of a gibberellin (GA) treatment to break seed dormancy, and the use of high through-put screening, we are able to rapidly and reliably identify herbicide sensitivity, tolerance, and resistance. From the initial screens, 7 biotypes were identified with no resistance, 9 with resistance to Beyond, 4 with resistance to Osprey, 5 with resistance to Olympus, and 2 with resistance to PowerFlex. Additionally, tolerance was discovered in 4 biotypes treated with Beyond and 2 treated with Olympus. None of the biotypes screened demonstrated resistance to glyphosate or Select Max. Degree of resistance is currently being tested in biotypes identifies from original screens.

Publications

Peer Reviewed Publications Nakka S, Godar AS, Wani PS, Thompson CR, Peterson DE, Roelofs J and Jugulam M. 2017. Physiological and molecular characterization of hydroxyphenylpyruvate dioxygenase (HPPD)-inhibitor resistant Palmer amaranth (Amaranthus palmeri S.Wats.). Front. Plant Sci. | doi: 10.3389/fpls.2017.00555 (KAES # 16-345-J). Varanasi VK, Bayromov S, Prasad PVV and Jugulam M. 2017. Expression profiles of psbA, ALS, EPSPS and other chloroplastic genes in response to PSII-, ALS-, and EPSPS-Inhibitor treatments in Kochia scoparia. American J of Plant Sci. 8:451-470 (KAES # 16-370-J). Ou J, P.W. Stahlman and Jugulam M. 2016: Reduced Absorption of Glyphosate and Decreased Translocation of Dicamba Contribute to Poor Control of Kochia (Kochia scoparia) at High Temperature. Pest Manag. Sci. DOI 10.1002/ps.4463. (KAES # 16-267-J). (IF 2.9) Jugulam M and Dillon AJ. 2016. Genomic Distribution of EPSPS copies conferring glyphosate resistance in Palmer amaranth and kochia. Indian J of Weed Sci. (KAES # 17-237-J). 48: 132-135. Tautges, N. E., T. S. Sullivan, C. L. Reardon, and I. C. Burke. 2016. Soil microbial diversity and activity linked to crop yield and quality in a dryland organic wheat production system. Appl. Soil Ecol. 108: 258-268. Tautges, N, Borrelli, E. P. Fuerst, and I. C. Burke. 2016. Competitive ability of rotational crops with weeds in dryland organic wheat production systems. Renew. Ag Food Sys. (doi: 10.1017/S1742170516000028). Young, F. L., D. K. Whaley, N. C. Lawrence, and I. C. Burke. 2016. Feral rye (Secale cereal) control in winter canola in the Pacific Northwest. Weed Technol. 30: 163-170. Kerbs, B. D., A.G. Hulting, and D. Lyon. 2017. Biology and management of scouringrush in dryland winter wheat.  Proc. West. Soc. Weed Sci. Vol.70: (In Press). Bobadilla, L. K., A.G. Hulting and C.A. Mallory-Smith. 2017.  Management of multiple resistant Italian ryegrass-characterizing resistant populations. Proc. West. Soc. Weed Sci. Vol.70: (In Press). Liu, M, B. D. Kerbs, A.G. Hulting and C. Mallory-Smith. 2016. Chracterization of multiple herbicide resistant Italian ruegrass (Lolium perenne ssp. multiflorum) populations from winter wheat field in Oregon. Proc. West. Soc. Weed Sci. Vol.69: (In Press). Roerig, K. C., B. J. Hinds-Cook, A.G. Hulting and C.A. Mallory-Smith. 2016.  Sensitivity of ‘Bobtail’ winter wheat to flufenacet-metribuzin. Proc. West. Soc. Weed Sci. Vol.69: (In Press). Roerig K. C., D. W. Curtis, A.G. Hulting, and C.A. Mallory-Smith. 2017.  ‘Bobtail’ winter wheat sensitivity to flufenacet/metribuzin by seeding rate and herbicide application rate.  2017 Western Society of Weed Science Research Progress Report. ISSN-0090-8142. 1pp. Roerig K. C., D. W. Curtis, A.G. Hulting, and C.A. Mallory-Smith. 2016.  Effect of planting date and application timing of flufenacet-metribuzon and pyroxasulfone on ‘Bobtail’ winter wheat yield and Italian ryegrass control.  2016 Western Society of Weed Science Research Progress Report. ISSN-0090-8142. 2pp. Ingegneri, L.M., M.P.Quinn, A.G. Hulting and C.A. Mallory-Smith. 2015. A short growing season negatively affects progeny vigor in jointed goatgrass (Aegilops cylindrical). Agricultural Sciences 6:315-324.   Conference Presentations Ou J, Stahlman PW, Fritz AK and Jugulam M. Dicamba- and glyphosate-resistant genes are not linked in kochia (Kochia scoparia). Weed Science Society of America, Annual Meetings, Tucson, AZ (abstract 150). Menzer S, Jugulam M and Thompson CR. Temperature effect on efficacy of POST-herbicides to control Palmer amaranth (Amaranthus palmeri) in grain sorghum. North Central Weed Science Society, Annual Meeting, Des Moines (abstract 131). Ou J, Thompson CR, Stahlman PW, Jugulam M. 2016. Efficacy of Glyphosate and Dicamba Tank-Mixes in Kochia. Western Society of Weed Science, Annual Meeting, Albuquerque, NM (abstract 135). Betha S, Thompson CR, Peterson DE, Jugulam M. 2016. Increased HPPD gene and protein expression contribute significantly to mesotrione resistance in palmer amaranth (Amaranthus palmeri). Weed Science Society of America, Annual Meeting, San Juan, PR (abstract 222). Bramhall JA, Varanasi A, Dille JA, Jugulam M. 2016. Impact of Crop Competition on Fitness of Glyphosate-Resistant Kochia (Kochia scoparia L. Schrad). Western Society of Weed Science, Annual Meeting, Albuquerque, NM (abstract 1). Ou J and Mithila J. 2015. Effect of elevated temperature on glyphosate and dicamba efficacy in broadleaf weeds. 25th Asia-Pacific Weed Science Society Conference, Hyderabad, India. Ou J and Jugulam M. 2015. Effect of Growth and Temperature on Dicamba and Glyphosate Efficacy in Kochia. Western Society of Weed Science, Portland, OR (abstract 30).   Extension Publications: Lyon, D.J., I.C. Burke, A.G. Hulting, and J.M. Campbell. 2017. Integrated management of mayweed chamomile in wheat and pulse crop production systems. Washington State University. PNW 695.   Extension Presentations: The biology and control of Russian-thistle was presented at seven pesticide recertification events held throughout eastern Washington. The topic was also presented at several other winter meetings held in the region. Herbicide resistance was the other major topic presented during the 2016-2017 winter meeting season.   Extension Decision Support Tools: Herbicide Mechanisms of Action (MOA) Tool @ <a href="https://herbicidemoa.cahnrs.wsu.edu">https://herbicidemoa.cahnrs.wsu.edu</a>. Winter Wheat Herbicide Efficacy Tables @ <a href="https://herbicideefficacy.cahnrs.wsu.edu">https://herbicideefficacy.cahnrs.wsu.edu</a>.

Impact Statements

Washington: Grower and industry awareness of herbicide resistance in downy brome, Italian ryegrass, jointed goatgrass, and Russian-thistle was increased through a series of winter meeting presentations, an article in Wheat Life magazine, and Timely Topic posts on the Wheat and Small Grains Website (smallgrains.wsu.edu). Wheat growers were provided with two new decision tools to help them make more informed decisions on herbicide use for the control of troublesome weeds.

Date of Annual Report: 05/05/2017

Report Information

Annual Meeting Dates: 03/13/2017 - 03/13/2017
Period the Report Covers: 10/01/2015 - 09/30/1016

Participants

Brief Summary of Minutes

Accomplishments

IDAHO REPORT Joan Campbell, Research and Instructional Associate; Traci Rauch, Senior Research Specialist; and Don Morishita, Extension Weed Scientist. PSES Dept, University of Idaho, 875 Perimeter Dr. MS 2339, Moscow, ID 83844; 208-885-7730; <a href="mailto:jcampbel@uidaho.edu">jcampbel@uidaho.edu</a> Objective 1 Results: Winter wheat tolerance was evaluated in Zidua formulations with and without irrigation, different rates and timings. A new liquid formulation decreased yield with same day irrigation compared to no irrigation. The same formulation in a non-irrigated study decreased yield at a high vs. low rate at a per-germination timing. No yield difference between rates if wheat was germinated. The second year of Anthem Flex winter wheat variety tolerance trial indicated some injury to Brundage96, but not Boundary, Cara, or Silver. In winter wheat, Italian ryegrass control with Anthem Flex was best with the highest rate at the postplant pre-germinated wheat timing. It was better than the preplant timing most likely due to the shorter time period for activation by rainfall (30 days preplant vs. 11 days postplant). Italian ryegrass control in spring wheat with Anthem Flex showed rate dependent Italian ryegrass control at the preplant timing vs. the germinated wheat timing. Anthem Flex rate and timing evaluations will be continuing in winter and spring wheat. A winter wheat/Italian ryegrass control study evaluated Zidua and Anthem Flex at the highest labeled rates with the following application times: pre-fertilization (shanked deep band liquid application equipment), post fertilization, postplant no germination and postplant germinated wheat. Italian ryegrass control with both herbicides was improved with less disturbance. The two postplant applications times differed due to time of activation with rainfall. Rain fell 18 days after the non-germinated application versus 3 days after the germinated wheat application. This study is being repeated in 2017. In 3 studies, rattail fescue was controlled 88% or greater with Zidua and Anthem Flex applied postplant preemergence in the fall alone or in combination with spring postemergence applications. Spring applied Everest, PowerFlex, and Maverick only suppressed rattail fescue. These studies will be repeated in 2017. Downy brome was controlled 80% or greater with Zidua, Anthem Flex and PowerFlex HL. Objective 2 Results: A field trial was established at UI research farms near Moscow and Genesee to examine tillage effects on rattail fescue. Winter wheat was direct-seeded in fall 2013. The rotation is winter wheat- spring wheat- spring chickpea. Tillage initiated in the fall 2014 included fall disc or chisel plow followed by spring field cultivation. A no-tillage treatment is included as a control. Heavy harrow will replace disc in year 2 and 3. The tillage is performed all 3 years, 2 years or 1 year for a total of 7 tillage regimes. Spring chickpea was seeded in 2016. Rattail fescue populations were low in the chickpea year of the tillage comparison study. The weed was found only in no-till and the one year of chisel plow. Tillage treatments were applied and winter wheat has been planted this fall for the third year of the study. Objective 3 Results: Two new broadleaf weed control herbicides in winter wheat were evaluated. Talinor (bicyclopyrone/bromoxynil) controlled a heavy mayweed chamomile population 98-99% which was better than Huskie and Starane Flex. Winter wheat yield was greater in the Talinor treatments compared to Widematch. Tarzec (halauxifen/pyroxsulam) controlled catchweed bedstraw 90-98% but did not control mayweed chamomile. A new postemergence grass herbicide, Osprey Xtra (mesosulfuron/thiencarbazone), controlled rattail fescue better than Everest and Osprey. Studies this spring will continue to evaluate these new herbicides for weed control efficacy. A new stripe rust fungicide (3 active ingredients) was evaluated in combination with different herbicides. The fungicide (at two different rates) combined with PowerFlex, Widematch and MCPA ester reduced yield compared to the check. Another study will be conducted in 2017. Objective 4 Results: Suspected-resistant weed seed samples collected from research plots and submitted by growers, fieldmen, and industry representatives were screened in the greenhouse. The weed seed samples were grown in the greenhouse and sprayed with suspected-resistant and non-resistant herbicides at twice the labeled rate. Susceptible plants were included to verify herbicide spray coverage and rate. Seeds were counted at planting with preemergence herbicides and plants are counted at emergence with postemergence herbicides. Untreated plants were included from each sample. Resistance was evaluated on plant survival and vigor compared to the untreated. In 2015, nine Italian ryegrass seed samples were treated with 12 different herbicides. No sample screened was resistant to Zidua, Dual Magnum, or glyphosate. Samples were resistant to Amber, Everest, Osprey, and PowerFlex (group 2) and Poast, Assure II, Shadow (clethodim) and Axial XL (group 1) and Axiom (group 15 and 5). Four wild oat seed samples were treated with 8 herbicides. No sample was resistant to Shadow, Poast, Beyond, Axial XL, and glyphosate. Samples were resistant to PowerFlex, Osprey (group 2), and Assure II (group 1). Objective 5 Results: Project personnel participated in cereal school meetings in north Idaho in January. Research information was presented at the Western Society of Weed Science regional meeting in March. Wheat system information was presented at International Weed Science Congress in June. Cereal research was also presented at field days in north and south Idaho in June and July.   KANSAS REPORT Kochia has been an economically important broadleaf weed in the US Great Plains including Kansas. However, in the recent years, Palmer amaranth has also become a major problem weed in Kansas. Specifically, evolution of multiple herbicide resistance in kochia and Palmer amaranth, is a serious threat to sustainable crop production. We have confirmed resistance to four modes of action of herbicides in a single kochia population from a crop field near Garden City, and this was reported in last year’s progress report. Additionally, environmental factors such as temperature shown to have significant effect in managing kochia populations with dicamba and glyphosate, commonly used herbicides for kochia management. We recently confirmed resistance to modes of action of herbicides in Palmer amaranth in several Counties in KS. Effect of Growth Temperature on Dicamba and Glyphosate Efficacy in Kochia. Kochia (Kochia Scoparia) is a major problematic weed in United States and Canada. Dicamba and Glyphosate offer effective herbicide options to control kochia. Previous research showed the efficacy of dicamba and glyphosate varied under different environmental conditions, including plant growth temperature. In this study, the effect of growth temperature on efficacy of dicamba and glyphosate in kochia was investigated. Dicamba- and glyphosate- susceptible kochia plants were grown in growth chambers maintained at different temperatures (day/night, °C): low (LT), 17.5/7.5; optimum (OT), 25.0/15.0; and high (HT), 32.5/22.5. When plants reached 8-10 cm tall, they were treated with 0, 1/32, 1/16, 1/8, 1/4, 1/2, 1X rates of dicamba (where X is 560 g·ae·ha-1) or glyphosate (where X is 840 g·ae·ha-1). Visual injury, fresh and dry biomass were recorded 4 weeks after treatment (WAT). Each treatment had 4-6 replications and experiments were done twice. Furthermore, dicamba and glyphosate uptake and translocation experiments were conducted using 6-8 cm tall kochia plants grown under above temperatures. Ten μL of dicamba (3.0 g·ae·L-1) or glyphosate (4.5 g·ae·L-1) containing 20,000 dpm·μL-1 14C radioactivity was applied on two newly matured leaves. At 24, 48 and 72 hours after treatment, the treated leaves (TL) were washed with 20% (v/v) ethanol solution with 0.5% (v/v) Tween-20. Subsequently, the TL, plant tissue above treated leaf (ATL) and below treated leaf (BTL) were harvested, dried and combusted to determine the amount of radioactivity. Results of dicamba dose-response on kochia show the ED50 of xxx, 50.2, 141.9 g·ae·ha-1, at LT, OT and HT, respectively. Whereas, for glyphosate, the ED50 at LT, OT and HT were yy.y, 60.4, and 173.5 g·ae·ha-1, respectively. Analysis of data of uptake and translocation studies indicate that the dicamba is more effective on kochia grown under LT, possibly because of increased translocation compared to plants grown under OT or HT. Similarly, glyphosate was also found more effective on kochia grown under LT than OT or HT. On the contrary, this increased efficacy of glyphosate under LT may be attributed to increased uptake of the herbicide rather than the translocation.   NEW MEXICO REPORT Erik Lehnhoff and Abdel Mesbah, New Mexico State University, Department of Entomology, Plant Pathology, and Weed Science In New Mexico, one study on tank mixing Huskie with broadleaf herbicides for weed management in winter wheat is being conducted in Clovis. Results show improved control of broadleaf weeds including kochia, Russian thistle and pigweed. It is too early in this study to present impacts.   WASHINGTON REPORT Drew J. Lyon and Ian C. Burke Research: Mayweed chamomile control in winter wheat with Talinor. A field study was conducted at the WSU Palouse Conservation Field Station near Pullman, WA to generate broadleaf weed control data with Syngenta’s Talinor herbicide in winter wheat. Talinor is a premixture of bromoxynil (Group 6) and bicyclopyrone (Group 27) herbicides. Talinor is tank mixed with CoAct+™, which is a safener. Huskie® contains pyrasulfotole, which is also a Group 27 herbicide, and bromoxynil, and is why it is used as a comparison treatment against this new active ingredient combination. Talinor alone, Talinor plus the tank mix partners tested, and Huskie alone provided greater control of mayweed chamomile 15 days after application than the Affinity Tankmix and WideMatch treatments. On June 17th, 57 DAT, Talinor treatments exhibited better control of mayweed chamomile than the Huskie treatments. The exception was Talinor + CoAct+ + Axial Star, which provided similar mayweed chamomile control to Huskie at 15 fl oz/A. There did not appear to be a rate response for Talinor treatments like there were with the Huskie treatments. When the final rating was taken on July 5th, 75 DAT, all treatments were providing good to excellent control of mayweed chamomile except Huskie at 11 fl oz/A. Talinor is an effective herbicide for mayweed chamomile control in winter wheat. Rush skeletonweed control in winter wheat following CRP takeout. Rush skeletonweed is a deep-rooted perennial species that has become well established on thousands of acres across eastern Washington while the land was out of wheat production in the Conservation Reserve Program (CRP). Recent changes to the CRP have resulted in many acres coming back into production and most often without prior skeletonweed control. Uncontrolled skeletonweed in the fallow phase of the rotation reduces seed-zone moisture and leaves inadequate soil moisture for germination of winter wheat in the fall. Areas where wheat fails to emerge are either late-seeded after fall rains replenish soil moisture or are left blank. In either case, crop yield is reduced. Herbicide control in the crop phase is one part of an overall strategy to reduce or eradicate skeletonweed from these production areas. We applied five different synthetic auxin herbicides to rush skeletonweed infested winter wheat on November 12, 2015 as the wheat was tillering and again prior to stem jointing on March 17, 2016, at a field site near LaCrosse, WA. In this trial, fall applications of Milestone or Stinger substantially controlled rush skeletonweed in the crop phase of the rotation without reducing grain yield. The experimental DPX-MAT28-128 and 2,4-D LV6 did not control skeletonweed well and appeared to reduce yield. Clarity did not lower yield, but also did not control skeletonweed. Downy brome vernalization and dormancy. Downy brome is arguably one of the worst invasive weed species in both natural and agronomic environments in the United States. Phenological variation is a key factor in the success of the species as a competitor in wheat production regions of the inland Pacific Northwest (PNW). Prior research characterized vernalization and flowering time requirements of downy brome collected from different environments, but no previous work has focused on the connection between such phenotypic responses with the genotypic control of vernalization. A series of common garden experiments was conducted involving 85 accessions of downy brome collected from within small grain production fields of Washington, Oregon, and Idaho. Results of previous common garden experiments identified differences in time to flowering of up to 19 days and time required for mature seed production of up to 21 days among accessions with little variation among siblings. From the common garden experiments cumulative growing degree days required for mature seed production for each accession was estimated using non-linear regression. A series of greenhouse experiments was conducted to characterize the vernalization requirements of downy brome accessions demonstrating differences in development and flowering time, and to determine if differences in expression of VRN1 orthologues is associated with differences in flowering time. Semiquantitative PCR was used to measure VRN1 expression in eight downy brome accessions with different vernalization requirements. Expression of a VRN1 orthologue was only observed in treatments were flowering occurred, suggesting that the molecular controls regulating vernalization and flowering in downy brome are likely conserved with those in related species. To address seed dormancy, research was conducted to explore the central hypotheses that differences in seed dormancy contribute to extensive phenotypic plasticity and adaptability in downy brome in small grain agricultural settings, and dormancy differences are regulated by changes in sensitivity to and signaling of the two plant hormones abscisic acid (ABA; dormancy promoting) and gibberellin (GA; germination stimulating). Phenotypic differences in seed dormancy were measured at physiological maturity utilizing a core collection of downy brome accessions from six population clusters across the dryland cropping areas in PNW (Lawrence and Burke). Seed dormancy and dormancy release were measured through changes in sensitivity to ABA and GA across an after-ripening time course, and in response to dark or light. Our preliminary findings suggest that: 1) at physiological maturity all accessions screened fall into the "dormant" category (0-25% germination) regardless of population cluster, 2) dormancy release occurs as a result of measurable changes in sensitivity to ABA and GA, as well as other environmental cues such as light, and 3) there are at least 4 distinct dormancy scenarios that exist among downy brome accessions which may not be associated with population cluster. Herbicide resistance screening of downy brome. We have established a herbicide resistance screening program. To date, initial screens for 34 individual biotypes from a total of 13 locations across the states of Washington and Oregon have been completed. With the implementation of new methods including the addition of a gibberellin (GA) treatment to break seed dormancy, and the use of high through-put screening, we are able to rapidly and reliably identify herbicide sensitivity, tolerance, and resistance. From the initial screens, 7 biotypes were identified with no resistance, 9 with resistance to Beyond, 4 with resistance to Osprey, 5 with resistance to Olympus, and 2 with resistance to PowerFlex. Additionally, tolerance was discovered in 4 biotypes treated with Beyond and 2 treated with Olympus. None of the biotypes screened demonstrated resistance to glyphosate or Select Max. Degree of resistance is currently being tested in biotypes identifies from original screens. Extension: The biology and control of Russian-thistle was presented at seven pesticide recertification events held throughout eastern Washington. The topic was also presented at several other winter meetings held in the region. Herbicide resistance was the other major topic presented during the 2016-2017 winter meeting season.

Publications

Peer Reviewed Publications Nakka S, Godar AS, Wani PS, Thompson CR, Peterson DE, Roelofs J and Jugulam M. 2017. Physiological and molecular characterization of hydroxyphenylpyruvate dioxygenase (HPPD)-inhibitor resistant Palmer amaranth (Amaranthus palmeri S.Wats.). Front. Plant Sci. | doi: 10.3389/fpls.2017.00555 (KAES # 16-345-J). Varanasi VK, Bayromov S, Prasad PVV and Jugulam M. 2017. Expression profiles of psbA, ALS, EPSPS and other chloroplastic genes in response to PSII-, ALS-, and EPSPS-Inhibitor treatments in Kochia scoparia. American J of Plant Sci. 8:451-470 (KAES # 16-370-J). Ou J, P.W. Stahlman and Jugulam M. 2016: Reduced Absorption of Glyphosate and Decreased Translocation of Dicamba Contribute to Poor Control of Kochia (Kochia scoparia) at High Temperature. Pest Manag. Sci. DOI 10.1002/ps.4463. (KAES # 16-267-J). (IF 2.9) Jugulam M and Dillon AJ. 2016. Genomic Distribution of EPSPS copies conferring glyphosate resistance in Palmer amaranth and kochia. Indian J of Weed Sci. (KAES # 17-237-J). 48: 132-135. Kerbs, B. D., A.G. Hulting, and D. Lyon. 2017. Biology and management of scouringrush in dryland winter wheat. Proc. West. Soc. Weed Sci. Vol.70: (In Press). Bobadilla, L. K., A.G. Hulting and C.A. Mallory-Smith. 2017. Management of multiple resistant Italian ryegrass-characterizing resistant populations. Proc. West. Soc. Weed Sci. Vol.70: (In Press). Liu, M, B. D. Kerbs, A.G. Hulting and C. Mallory-Smith. 2016. Chracterization of multiple herbicide resistant Italian ruegrass (Lolium perenne ssp. multiflorum) populations from winter wheat field in Oregon. Proc. West. Soc. Weed Sci. Vol.69: (In Press). Roerig, K. C., B. J. Hinds-Cook, A.G. Hulting and C.A. Mallory-Smith. 2016. Sensitivity of ‘Bobtail’ winter wheat to flufenacet-metribuzin. Proc. West. Soc. Weed Sci. Vol.69: (In Press). Roerig K. C., D. W. Curtis, A.G. Hulting, and C.A. Mallory-Smith. 2017. ‘Bobtail’ winter wheat sensitivity to flufenacet/metribuzin by seeding rate and herbicide application rate. 2017 Western Society of Weed Science Research Progress Report. ISSN-0090-8142. 1pp. Roerig K. C., D. W. Curtis, A.G. Hulting, and C.A. Mallory-Smith. 2016. Effect of planting date and application timing of flufenacet-metribuzon and pyroxasulfone on ‘Bobtail’ winter wheat yield and Italian ryegrass control. 2016 Western Society of Weed Science Research Progress Report. ISSN-0090-8142. 2pp. Ingegneri, L.M., M.P.Quinn, A.G. Hulting and C.A. Mallory-Smith. 2015. A short growing season negatively affects progeny vigor in jointed goatgrass (Aegilops cylindrical). Agricultural Sciences 6:315-324. Tautges, N. E., T. S. Sullivan, C. L. Reardon, and I. C. Burke. 2016. Soil microbial diversity and activity linked to crop yield and quality in a dryland organic wheat production system. Appl. Soil Ecol. 108: 258-268. Tautges, N, Borrelli, E. P. Fuerst, and I. C. Burke. 2016. Competitive ability of rotational crops with weeds in dryland organic wheat production systems. Renew. Ag Food Sys. (doi: 10.1017/S1742170516000028).  Young, F. L., D. K. Whaley, N. C. Lawrence, and I. C. Burke. 2016. Feral rye (Secale cereal) control in winter canola in the Pacific Northwest. Weed Technol. 30: 163-170. Extension Publications Lyon, D.J., I.C. Burke, A.G. Hulting, and J.M. Campbell. 2017. Integrated management of mayweed chamomile in wheat and pulse crop production systems. Washington State University. PNW 695. Conference Presentations Ou J, Stahlman PW, Fritz AK and Jugulam M. Dicamba- and glyphosate-resistant genes are not linked in kochia (Kochia scoparia). Weed Science Society of America, Annual Meetings, Tucson, AZ (abstract 150). Menzer S, Jugulam M and Thompson CR. Temperature effect on efficacy of POST-herbicides to control Palmer amaranth (Amaranthus palmeri) in grain sorghum. North Central Weed Science Society, Annual Meeting, Des Moines (abstract 131). Ou J, Thompson CR, Stahlman PW, Jugulam M. 2016. Efficacy of Glyphosate and Dicamba Tank-Mixes in Kochia. Western Society of Weed Science, Annual Meeting, Albuquerque, NM (abstract 135). Betha S, Thompson CR, Peterson DE, Jugulam M. 2016. Increased HPPD gene and protein expression contribute significantly to mesotrione resistance in palmer amaranth (Amaranthus palmeri). Weed Science Society of America, Annual Meeting, San Juan, PR (abstract 222). Bramhall JA, Varanasi A, Dille JA, Jugulam M. 2016. Impact of Crop Competition on Fitness of Glyphosate-Resistant Kochia (Kochia scoparia L. Schrad). Western Society of Weed Science, Annual Meeting, Albuquerque, NM (abstract 1). Ou J and Mithila J. 2015. Effect of elevated temperature on glyphosate and dicamba efficacy in broadleaf weeds. 25th Asia-Pacific Weed Science Society Conference, Hyderabad, India. Ou J and Jugulam M. 2015. Effect of Growth and Temperature on Dicamba and Glyphosate Efficacy in Kochia. Western Society of Weed Science, Portland, OR (abstract 30).

Impact Statements

Idaho. Information presented at cereal schools, field tours, and extension meetings will aid growers in making the best economic and ecological decisions for weed control in their wheat production systems.

Date of Annual Report: 05/08/2018

Report Information

Annual Meeting Dates: 03/12/2018 - 03/12/2018
Period the Report Covers: 10/01/2016 - 09/30/2017

Participants

Barroso, Judit (judit.barroso@oregonstate.edu) – Oregon State University
Campbell, Joan (jcampbel@uidaho.edu) - University of Idaho
Creech, Cody (ccreech2@unl.edu) - University of Nebraska
Creech, Earl (earl.creech@usu.edu) - Utah State University
Hulting, Andy (Andrew.hulting@oregonstate.edu) - Oregon State University
Kumar, Vipan (vkumar@ksu.edu) - Kansas State University
Lehnhoff, Erik (lehnhoff@nmsu.edu) - New Mexico State University
Lyon, Drew (drew.lyon@wsu.edu) - Washington State University
Mallory-Smith, Carol (carol.mallory-smith@oregonstate.edu) - Oregon State University
Manuchehri, Misha (misha.manuchehri@okstate.edu) - Oklahoma State University
Morishita, Don (don@uidaho.edu) - University of Idaho
Ransom, Corey (corey.ransom@usu.edu) - Utah State University
Rauch, Traci (trauch@uidaho.edu) - University of Idaho
Roering, Kyle (kyle.roering@oregonstate.edu) - Oregon State University
Seipel, Tim (timothy.seipel@montana.edu) - Montana State University
Thompson, Curtis (cthompso@ksu.edu) - Kansas State University
Young, Steve (steve.young@usu.edu) - Utah State University
Westra, Phil (philip.westra@colostate.edu ) - Colorado State University

Brief Summary of Minutes

Erik Lehnhoff, chair, called the meeting to order at 3:00 pm. Attendance sheet was passed and attendees introduced themselves. Michael Harrington, executive director of Western Association of Agricultural Experiment Station Directors, attending by phone, gave a Multistate Committee Update and a presentation on the new farm bill.

Unfortunately, Andrew Kniss could not attend the meeting and we could not move forward on the seeding direction study. We decided to contact him later to see if he could give us an update.

The second item of discussion was on feral rye collection and procedure to conduct a common garden. Scientists were supposed to send seeds to Ian Burke following a protocol sent by Nevin Lawrence on May 15, 2017. We discussed the goal of the common garden. We mentioned that we would like to understand its invasive characteristic in relation to the different sites, elevation, or slope orientation from where it was collected. The objective is to study the genotypic and phenotypic variability of this species and potentially, in a near future, applying for a federal grant where the weedy perspective could be compared with the breeding perspective.

The third item of discussion was potential grant proposals. Andy Hulting proposed to work on the Italian ryegrass problem in collaboration. He mentioned the multiple herbicide resistances that the species has developed and the fact that growers are running out of options. He proposed to apply for a grant to the NIFA-CPPM program with the idea of pest management using fewer herbicides. After a discussion on project focus, we realized that AFRI could be a more convenient program to have funds for different states/groups interested in the collaborative work.

The fourth item was other ideas for research. We discussed the matter about the biocontrol (bacteria) found by Ann Kennedy to control downy brome and other grasses. It seems that we all agreed that the bacteria does not really seem to work but we need to write something in order to put the word out in a near future. Steve Young informed about his recently awarded project on cover crops to control kochia and asked for other scientists who could be interested in working on cover crops in other states. Several scientists in the room showed interest in that collaboration. Several species were discussed as options to be used for cover crops.

Misha Manuchehri was elected secretary/chair elect for next year. Judit Barroso will serve as chair. The next meeting will be held March 11, 2019, 3:00-5:00 PM before the Western Society of Weed Science meeting in Denver, CO. Meeting adjourned at 4:45 PM.

Accomplishments

IDAHO REPORT Joan Campbell, Principle Researcher; Traci Rauch, Senior Research Specialist; and Don Morishita, Extension Weed Scientist. Plant Science Department, University of Idaho, 875 Perimeter Dr. MS 2333, Moscow, ID 83844-2333; 208-885-7730; <a href="mailto:jcampbel@uidaho.edu">jcampbel@uidaho.edu</a> Objective 1. Results. Using GPS, Italian ryegrass seed was collected in the same locations as in a 2006/2007 herbicide-resistant survey. Italian ryegrass not present due to the cropping system will be collected in 2018. New and additional sites were surveyed for a total of 50 sampling locations. Seed was collected by hand in the center of the infestation in each field. Seeds from each sample along with a known susceptible biotype will be screened in the greenhouse winter 2017/2018 against herbicides used in our area to control Italian ryegrass. Untreated plants are included from each sample. Objective 1. Outcomes/Impacts. Identifying changes in herbicide resistance within previously sampled Italian ryegrass collections will aid growers in understanding how their weed control management practices, including tillage and crop and herbicide rotation, have altered the makeup of the population.  Objective 2. Results. A very wet fall 2016 and spring 2017 (rainfall of 6 inches in October and 7 inches in March) along with an extremely heavy population of Italian ryegrass produced multiple germination events and reduced Italian ryegrass control to inadequate levels in the two following Italian ryegrass studies. In winter wheat, Italian ryegrass control with Anthem Flex was best with the highest rate at the preplant timing but was similar to the highest rate postplant pre-germinated wheat timing. Both application times received rainfall within 5 days. Anthem Flex rate and timing evaluations will be continuing in winter and spring wheat. A winter wheat/Italian ryegrass control study evaluated Zidua and Anthem Flex at the highest labeled rates with the following application times:  pre-fertilization (dry fertilizer followed by field cultivation), post fertilization, postplant no germination and postplant germinated wheat. Italian ryegrass control with both herbicides was improved with less disturbance. The two postplant application times were activated by rainfall 2 days after application and did not differ in Italian ryegrass control. This study is being repeated in 2018. Rattail fescue was controlled 94% or greater with Axiom, Zidua, and Anthem Flex applied postplant preemergence in the fall alone or in combination with spring postemergence applications. Spring applied Everest, PowerFlex, and Maverick only suppressed rattail fescue. This study will be repeated in 2018. Downy brome was controlled 80% or greater with Zidua, Anthem Flex and Axiom alone or combined with Osprey Xtra.  Objective 2. Outcomes/Impacts: Zidua (group 15) was registered for annual grass control, including Italian ryegrass and rattail fescue, in winter and spring wheat in spring 2014. Zidua registration has aided in control of group 1 and 2 resistant Italian ryegrass. Very few herbicides control rattail fescue. Zidua and Anthem treatments controlled rattail fescue 90-99% in 2016.Winter wheat yield was not reduced by Zidua when 0.5 inch of sprinkler irrigation was applied immediately after planting and spraying on the same day (worst-case scenario). Wheat had minimal injury in nine conventional-tilled (chisel plowed/field cultivated) sites and in five direct-seed locations. U of I studies were instrumental in implementing Zidua label changes including an increased use rate and a preplant application time in winter wheat. These label changes have aided growers by giving them more options to improve weed efficacy. Anthem Flex also was registered in wheat fall 2014. Our Anthem Flex studies were useful to FMC when drafting rates and timings for their label. This information will help growers use these products safely and effectively to control grass weeds with minimal crop injury. These registrations provide needed tools to help control herbicide resistant weeds, especially Italian ryegrass.  Objective 3. Results: A field trial was established at UI research farms near Moscow and Genesee to examine tillage effects on rattail fescue. Winter wheat was direct-seeded in fall 2013. The rotation is winter wheat- spring wheat- spring chickpea. Tillage initiated in the fall 2014 included fall disc or chisel plow followed by spring field cultivation. A no-tillage treatment is included as a control. Heavy harrow replaced disc in year 2 and 3. The tillage was performed all 3 years, 2 years or 1 year for a total of 7 tillage regimes. Spring chickpea was seeded in 2016. Rattail fescue populations were low in the chickpea year of the tillage comparison study. The weed was found only in no-till and the one year of chisel plow. Tillage treatments were applied and winter wheat was planted fall 2016 for the third year of the study. Winter wheat yield was confounded by standing water at Moscow and rodent damage at Genesee. Tillage treatments have ended but chickpea will be planted in the spring for the fourth year of the study.  Objective 3. Outcomes/Impacts: Knowledge of cultural controls, crop rotation and tillage is limited for rattail fescue control. Current information is speculative at best. Herbicide usage is the only known research-based tool for rattail fescue control. Tillage is important but research on how invasive and how many times is unknown. This data will help growers take an integrated weed management approach to reducing rattail fescue and increasing crop yield.  Objective 4. Two new broadleaf weed control herbicides in winter wheat were evaluated. Talinor (bicyclopyrone/bromoxynil) controlled catchweed bedstraw 70-75% which was not as good as Widematch and Starane Flex at 90-91%. In winter wheat, Quelex (halauxifen/ florasulam) combined with PowerFlex controlled catchweed bedstraw 96% which was similar to clopyralid containing treatments 90-99%. In spring wheat, Quelex alone controlled common lambsquarters 96%. A new postemergence grass herbicide, Osprey Xtra (mesosulfuron/ thiencarbazone) controlled rattail fescue (89-98%) better than Everest (50%) and Osprey (54-82%). Studies in 2018 will continue to evaluate these new herbicides for weed control efficacy. Nexicor, a stripe rust fungicide, was evaluated in combination with different herbicides. The fungicide combined with PowerFlex and Widematch, Osprey and Huskie or Beyond and Talinor did not reduce yield compared to the fungicide alone or the untreated check.  Objective 4. Outcomes/Impacts: Examining tolerance and efficacy of newly registered and soon-to-be registered herbicides is critical to the development of unbiased information on the use of these products by Idaho wheat growers. Evaluating combinations of fungicides with herbicides for crop response and weed control is also important. This data assists in timely federal registration of new compounds. Herbicides with new and different modes of action are necessary to reduce or stop the development of herbicide resistant weeds. Talinor and Quelex may be options for possible control of herbicide resistant broadleaf weeds.  Objective 5. Suspected-resistant weed seed samples collected from research plots and submitted by growers, fieldmen, and industry representatives were screened in the greenhouse. The weed seed samples were sprayed with suspected-resistant and non-resistant herbicides at twice the labeled rate. Susceptible plants were included to verify spray coverage and rate. Seeds were counted at planting with preemergence herbicides and plants counted at emergence with postemergence herbicides. Untreated plants were included from each sample. Resistance was evaluated on plant survival and vigor compared to the untreated. Six Italian ryegrass seed samples were treated with 12 different herbicides. No sample screened was resistant to Zidua, Shadow (clethodim), or glyphosate. Samples were resistant to Amber, Everest, Osprey, and PowerFlex (group 2) and Poast, Assure II, and Axial XL (group 1) and Dual Magnum (group 15) and Axiom (group 15 and 5). Five wild oat seed samples were treated with 8 herbicides. No sample was resistant to Shadow, Poast, Beyond, Axial XL, and glyphosate. Samples were resistant to PowerFlex, Osprey (group 2), and Assure II (group 1). Five downy brome samples were screened with four herbicides. Samples were resistant to PowerFlex, Beyond, Olympus, and Maverick which are all group 2 herbicides.  Objective 5. Outcomes/Impacts: Screening weed seed samples enables growers to combat herbicide resistance by adjusting their weed control approach so that it includes rotating chemicals, changing crop rotations, and implementing other cultural practices.  Objective 6. Results: Project personnel participated in cereal schools in north Idaho in January. Research information was presented at the Western Society of Weed Science meeting in March. Cereal research was also presented at field days in north and south Idaho in June and July.  Objective 6. Outcomes/Impacts: Information presented at cereal schools, field tours, and extension meetings will aid growers in making the best economic and ecological decisions for weed control in their wheat production systems. OKLAHOMA REPORT Misha Manuchehri, Extension Weed Specialist, Department of Plant and Soil Sciences, Oklahoma State University, 371 Agricultural Hall, Stillwater, OK 74078. 405-744-9588. <a href="mailto:misha.manuchehri@okstate.edu">misha.manuchehri@okstate.edu</a>  Identification and Management of ACCase Resistant Italian Ryegrass. Axial XL resistant Italian ryegrass biotypes are suspected in Oklahoma; however, only plants with an increased tolerance have been identified in greenhouse screenings. The use of ground 15 herbicides may improve the control of these difficult-to-manage plants. Several studies were conducted throughout Oklahoma to evaluate the use of Zidua (pyroxasulfone) and Anthem Flex (pyroxasulfone + carfentrazone) and Axiom (flufenacet+metribuzin) to control Italian ryegrass. Control was at least 95% for all treatments that included pyroxasulfone DPRE or VEPOST or pinoxaden VEPOST. Similar control was achieved with pyroxasulfone + carfentrazone and flufenacet + metribuzin. Timely rains and proper herbicide to soil contact contributed to the success of these treatments.  Horseweed Management in Winter Wheat. Traditional broadleaf postemergence herbicide treatments vs. those containing Quelex (florasulam + halauxifen), Sentrallas (thifensulfuron methyl + fluroxypyr), and Talinor (bicyclopyrone + bromoxynil) were compared when applied to multiple growth stages of horseweed (5, 10, and 15 cm) throughout Oklahoma during the 2016-17 field season. End of season control of 5 cm horseweed was 90% or greater in all treatments with the exception of metsulfuron + chlorsulfuron + MCPA and metsulfuron + 2,4-D. For 10 cm plants, all treatments controlled horseweed 90% or greater with the exception of thifensulfuron methyl + fluroxypyr (low and high rates) + MCPA and 2,4-D alone. Where horseweed rosette size was the largest (15 cm), only those treatments containing florasulam + halauxifen achieved 90% control or greater. Finally, no visual crop injury was observed following any treatment. An additional year of data is currently being collected to support these findings.  Rescuegrass Management in Winter Wheat. Rescuegrass is one of the most challenging winter annual weeds to manage in Oklahoma. There are few herbicides labeled for rescuegrass control in winter wheat and for the ones that are labelled, control is often inconsistent. To evaluate herbicide systems for rescuegrass management, two trials were conducted in Altus and Yukon, OK during the 2017-18 field season. At both Altus and Yukon, rescuegrass control was the highest following fall postemergence applications of imazamox. At Altus, imazamox + AMS + NIS or MSO controlled rescuegrass 93 to 96%. At Yukon, imazamox + AMS + MSO achieved 69% control while imazamox + AMS + NIS controlled rescuegrass 56%. All other treatments at Yukon performed poorly as a six inch rain event followed PRE treatments and control with pyroxsulam was low (<10%). Conversely, at Altus, PRE treatments of glyphosate alone or glyphosate + flucarbazone-sodium or propoxycarbazone-sodium achieved 64 to 69% control. Preemergence treatments of glyphosate alone or glyphosate + flucarbazone-sodium or propoxycarbazone-sodium + pyroxsulam achieved 80 to 84% control. Trials will be repeated next growing season to further evaluate these systems.  CoAXium Systems for Management of Feral Rye. Applications of Aggressor herbicide + NIS, COC, MSO, and/or AMS were applied to feral rye in the fall and/or spring of the 2016-17 field season. Fall treatments alone and a fall treatment followed by a spring treatment achieved the highest levels of control (nearly 100%). A similar trial is being conducted this growing season in feral rye and rescuegrass.  IMPACTS: Through a series of Extension presentations, awareness of herbicide resistance and integrated weed management has been increased in Oklahoma. OREGON REPORT Judit Barroso, Weed Scientist. Crop and Soil Science Department, Columbia Basin Agricultural Research Center, Oregon State University. (541)2784394. <a href="mailto:Judit.Barroso@oregonstate.edu">Judit.Barroso@oregonstate.edu</a>  Prickly lettuce (Lactuca serriola) control with Talinor® (bicyclopyrone + bromoxynil) in spring wheat. Field experiments were conducted at two locations in eastern Oregon, the Columbia Basin Agricultural Research Center (CBARC) near Adams and the Sherman Research Station (SRS) near Moro. The objectives were to evaluate the control of prickly lettuce in spring wheat with Syngenta’s new herbicide in comparison to other herbicides commonly used to control this weed and to determine the potential for crop injury. Talinor® provided complete early season control of prickly lettuce (rosette stage) when applied at the two highest rates (0.221 and 0.252 lb ae/acre). This control was similar to the control provided by the two highest rates (0.217 and 0.241 lb ae/acre) of Huskie® (pyrasulfotole + bromoxynil) and the label rate (0.313 + 0.313 + 0.126) of Kochiavore® (2,4-D + bromoxynil + fluroxypyr). However, late-season control of prickly lettuce (stem elongation) declined for all but the highest rate of Talinor®, which retained excellent control similar to all rates of Huskie® and Kochiavore®. No significant crop injury was observed at either site for any of the treatments under the conditions tested. However, more testing would be needed to know this effect on different wheat varieties, environmental conditions, or crop growth stages. Grain yield was not significantly different among treatments.  Weed control with Quelex® (halauxifen-methyl + florasulam) in winter and spring wheat. Two field experiments were conducted at the Columbia Basin Agricultural Research Center (CBARC) near Adams, one in winter wheat and other in spring wheat, to evaluate the control of Quelex on several weed species. All treatments included in both studies were applied with Act. 90 (0.5%v/v) and AMS (1.52 lb/ac) in addition to the herbicide/s. In winter wheat, the treatments were applied on April 15, 2017 with a CO2 powered backpack sprayer to deliver 15 gal/acre. At application time, the crop and downy brome (Bromus tectorum) were in tillering stage and prickly lettuce (Lactuca serriola) had 2-4 pairs of leaves. Downy brome control was improved with Quelex (0.75 oz/ac) + Powerflex (2 oz/ac) in comparison with Powerflex alone. Prickly lettuce control was very good (higher than 95% control) and similar for the treatments: Quelex (0.75 oz/ac) + Widematch (16 fl oz/ac), Talinor (13.7 fl oz/ac), Huskie (13.5 fl oz/ac), and Perfectmatch (20 fl oz/ac). The control of prickly lettuce with Quelex alone was slightly lower than to the control obtained with 2,4-D ester (8 fl oz/ac) (approx. 75% on average). No crop injury was observed with the new herbicide on the Bobtail winter wheat variety. In spring wheat, the treatments were applied on May 18, 2017 with the same equipment and set ups. The crop was in the tillering stage and the weeds at 3-6 leaf pair stage. The best treatments for prickly lettuce control, as with the winter wheat, were Widematch (21.3 fl oz/ac) + Quelex and Huskie + Quelex. The Quelex alone treatment showed only prickly lettuce suppression. However, tumble mustard (Sisymbrium altissimum) control in the Quelex alone treatment showed a similar percentage of control (all above 93%) as those tank mixed with Widematch, 2,4-D ester, MCPA, Perfectmatch, Huskie or, Bronate Advanced. Impact Statement: To delay the development of herbicide resistance cases, growers need to rotate or tank mix herbicides with different mode of action as much as they can. The results of these research trials provide growers with efficacy and crop safety information of new herbicides on several problematic weed species of the PNW to help them improve their weed management strategies.  Downy brome (Bromus tectorum) and rattail fescue (Vulpia myuros) control with Osprey Extra in winter wheat. Two field experiments were conducted at two locations in eastern Oregon, the Columbia Basin Agricultural Research Center (CBARC) near Adams and the Sherman Research Station (SRS) near Moro. The objectives were to evaluate the control of downy brome and rattail fescue in winter wheat with the new Bayer herbicide (that is not registered yet) in comparison to Osprey® (mesosulfuron-methyl) and Olympus® (propoxycarbazone-sodium) and to evaluate crop safety. At SRS, herbicides were applied on March 31 of 2016 with a CO2-powered backpack sprayer to deliver 15 gal/acre at 43 lb/sq inch, when the crop was initiating tillering and both weeds were slightly behind that growth stage (most of them had five leaves and they were about to tiller). Olympus® showed better control of downy brome than Osprey or Osprey Extra. However, the differences were not significant according to the Bonferroni test. Olympus only showed suppression for rattail fescue. Osprey Extra showed a higher percentage of rattail fescue control than Osprey but the differences were not significant according to the Bonferroni test. Both treatments (Osprey and Osprey Extra) showed significantly higher rattail fescue control than Olympus. The wheat yield did not show significant differences among treatments and no significant crop injury was observed. At CBARC, where only downy brome was present in the experiment area, herbicides were applied on April 15 of 2017 with the same equipment and set ups. Crop and weeds were finishing tillering stage. The three treatments did not show significant differences. Data from Olympus and Osprey Extra were very consistent in the four repetitions. Wheat yield did not show significant differences among treatments, but in all the treatments it was higher than in the control plots, which had an 11.7% on average of lower yield. No significant crop injury was observed. Impact Statement: Collaborating with the industry to understand how potential new herbicides work in the different regions is critical to provide growers with unbiased information once the product is available on the market. Growers are normally very interested in new products that can help them with the day-to-day problem of resistant weeds.  UTAH REPORT Earl Creech, Extension Agronomist; Corey Ransom, Extension Weed Scientist; Steve Young, Weed Scientist. Plants, Soils & Climate Department, Utah State University, 4820 Old Main, Logan, UT 84322; 435-797-0139; <a href="mailto:steve.young@usu.edu">steve.young@usu.edu</a>  Research: Kochia-cover crop study. There is a paucity of research on tactics other than herbicides for controlling kochia in wheat. Thus, with funding from the Western Integrated Pest Management (IPM) Center, a 1-year project was initiated on March 1, 2018, as part of a long-term study evaluating a more diverse set of tactics to be included in an IWM approach for managing kochia in wheat. In this project, three tactics in two weed control categories (physical and cultural) will be tested either alone or in combination with a third category (chemical). The hypothesis is that cover crops, mulches, and planting dates and seeding rates will be more effective than herbicides alone for effectively controlling kochia in wheat. The results will be shared with growers in an effort to broaden the adoption of ecological approaches into IWM plans for controlling kochia in wheat. The objective of this study is to evaluate the influence of cover crops, and planting dates and rates on kochia populations in wheat fields of Utah and southern Idaho. Planting dates and rates will be assessed as secondary tactics (e.g., early or late season plantings – avoidance, size advantage; high rates – resource use, competitive advantage) against kochia in combination with cover crops as a primary tactic.  Extension: Kochia-cover crop study. Several avenues will be used to provide growers and their advisors useful facts and promote the exchange of information. Growers will engage in hands-on extension activities such as sharing their knowledge at joint field day events. Specific methods for disseminating results will include: 1) establishing research at university field sites, 2) conducting field days in partnership with local growers, crop advisors and seed dealers (Utah Seed), 3) updating county educators, regional specialists, and private crop advisors at in-service meetings, 4) uploading findings on university extension and private organization websites, 5) presenting findings at local and regional meetings and conferences, 6) announcing project findings in local newsletters, newspapers for growers, and during statewide and regional speaking engagements, and 7) integrating research findings into course teachings that target next generation ag-professionals.  Impacts: Kochia-cover crop study. Outcomes: Growers will benefit from our project through increased understanding and directly implementable results. At the beginning of the project, we will collect baseline data on wheat grower practices and the impacts of kochia on their farm. A follow up survey will be conducted at the field day to determine what changes have occurred in awareness, knowledge, attitude, or skills related to learning and resulting actions, if any. Even though only a 1-year project, we expect growers to engage more than if it was just a survey sent to them by mail. The Extension activities associated with the project will require in-person grower participation and response. WASHINGTON REPORT Drew J. Lyon, Extension Weed Scientist; Ian C. Burke, Weed Scientist. Crop and Soil Sciences Department, Washington State University, Pullman, WA 99164-6420; 509-335-2961. <a href="mailto:drew.lyon@wsu.edu">drew.lyon@wsu.edu</a>  Research: Rattail fescue control in winter wheat with Osprey Xtra herbicide. A field study was conducted at Wolf Farms near Uniontown, WA to evaluate Osprey Xtra for its postemergence rattail fescue control in direct-seeded hard red winter wheat. Osprey Xtra (thiencarbazone + mesosulfuron) active ingredients are both ALS-inhibiors (Group 2). Osprey Xtra also contains mefenpyr-diethyl, which is used as a safener in combination with the active ingredients for selective weed control in wheat. Osprey Xtra was compared to the current formulation of Osprey, which only contains (mesosulfuron + mefenpyr-diethyl). Osprey Xtra is not yet registered for use in wheat. The addition of one or two broadleaf emulsifiable concentrate (EC) herbicide formulations have been shown to increase the activity of Osprey Xtra on rattail fescue. Postemergence treatments were applied on April 21, 2017 with a CO2-powered backpack sprayer set to deliver 10 gpa at 43 psi at 2.3 mph. At the time of application, the majority of rattail fescue had two detectible tillers and was 0.75-inch tall and the wheat had three detectable tillers with a height ranging from 6 to 8 inches. Rattail fescue was uniformly distributed across the trial area. Osprey Xtra provided better control of rattail fescue than the current Osprey formulation. Rattail fescue control was not improved by tank mixing one or two EC herbicide formulations with Osprey Xtra. Osprey + Huskie + Brox-M provided comparable control to Osprey Xtra. Wheat yield was negatively impacted by the presence of rattail fescue. Wheat in the Osprey Xtra, Osprey Xtra + Huskie, Osprey + Huskie + Brox-M and Osprey Xtra + Huskie + WideMatch treatments exhibited an increase in yield compared to the nontreated check.  Common lambsquarters control is spring wheat with Quelex herbicide. A field study was conducted at the Spillman Farm near Pullman, WA to evaluate Quelex for the control of common lambsquarters in spring wheat. Quelex is a new herbicide premixture for the control of annual broadleaf weeds in wheat (including durum), barley and triticale. Quelex contains florasulam and halauxifen. Florasulam is an ALS-inhibitor (Group 2) and halauxifen is a new synthetic auxin (Group 4). Postemergence treatments were applied on June 8th with a CO2-powered backpack sprayer set to deliver 10 gpa at 45 psi at 2.3 mph. The wheat had 2 tillers and was 9 inches tall. The common lambsquarters were 1.5 inches tall and at an average density of 1,700 plants per square yard. No significant crop injury was observed with any of the herbicide treatments. Bromoxynil-based treatments including Huskie, Quelex + Huskie and Quelex + Bromac were the first to show excellent control of common lambsquarters. Lambsquarters in these treatments exhibited pronounced leaf tip burning. Plants in the other treatments exhibited more twisting, but leaves remained green and healthy. Quelex as a standalone product was very slow acting and on the final rating date was not providing commercially acceptable control. The addition of Quelex to Huskie did not increase its performance. The addition of Quelex to WideMatch did increase its performance on common lambsquarters.  Impact Statement: Grower and industry awareness of herbicide resistance continued to increase in 2017 through a variety of presentations and articles in the popular press and through Timely Topic posts on the Wheat and Small Grains Website (<a href="http://smallgrains.wsu.edu/">smallgrains.wsu.edu</a>). Wheat growers were provided with two new decision tools to help them make more informed decisions on herbicide use for the control of troublesome weeds. Growers were also provided with efficacy and crop safety information for newer herbicide products in wheat.

Publications

Peer Review Publications:  Aramrak, A., N.C. Lawrence, V.L. Demacon, A.H. Carter, K.K. Kidwell, I.C. Burke, and C.M Steber. 2018. Isolation of mutations conferring increased glyphosate resistance in spring wheat. Crop Sci. 58:84-97. Barroso J., J. Gourlie, L. Lutcher, L. Mingyang and, C.A. Mallory-Smith. 2017. Identification of glyphosate resistance in Salsola tragus in Northeastern Oregon. Pest Manag. Sci. 74: 1089-1093. San Martin C., D.J. Lyon, H.C. Wetzel, J.A. Gourlie and, J. Barroso. 2018. Weed control with bicyclopyrone + bromoxynil in wheat. Crop, Forage & Turfgrass Manag. (Accepted). Kumar, V., J.F. Spring*, P. Jha, D.J. Lyon, and I.C. Burke. 2017. Glyphosate-resistant Russian-thistle (Salsola tragus) identified in Montana and Washington. Weed Technol. 31:238-251. Lawrence, N.L., A.L. Hauvermale, A. Dhingra, and I.C. Burke. 2017. Population structure and genetic diversity of Bromus tectorum within the small grain production region of the Pacific Northwest. Ecol. Evol. 7:8316-8328. Schlatter, D.C., C. Yin, I. Burke, S. Hulbert, and T. Paulitz. 2017. Impacts of repeated glyphosate use on wheat—associated bacteria are small and depend on glyphosate use history. Appl. Eviron. Microbiol. 83:e01354-17.  Extension Publications: Barroso J, Gourlie J, Lutcher L, Mingyang L and Mallory-Smith C. 2017. Identification of glyphosate resistance in Russian thistle in Northeastern Oregon. Dryland Field Day Abstracts, June 2017. pp. 11. Hagerty C, Barroso J, Machado S, Wysocki D, Schroeder K, Carter P, and Murray T. 2017. Assessment of soil acidity on soil borne pathogens, weed spectrum, herbicide activity, and yield on dryland wheat production. Dryland Field Day Abstracts, June 2017, pp. 20-21. Burke, I.C., K. Kahl, N. Tautges, and F.L. Young. 2017. Integrated Weed Management. In Yorgey, G. and C. Kruger, eds. Advances in Dryland Farming in the Inland Pacific Northwest, Washington State University Extension Publication EM108, Pullman, WA. 353-398. Lofton, J. J., M. R. Manuchehri, and B. Haggard. 2017. Weedy Mustards of Oklahoma. Oklahoma State University, PSS-2787. Lyon, D.J., I.C. Burke, and J.M. Campbell. 2018. Integrated management of mustard species in wheat production systems. (PNW703). Lyons, D. J., I.C. Burke, A.G. Hulting, and J.M. Campbell. 2017. Integrated management of mayweed chamomile in wheat and pulse crop production systems. PNW 695. p.7.  Conference Presentations: Barroso J., C. San Martin, M. Thorne M. and, D.J. Lyon. 2018. Seed retention of major weed species at harvest in the PNW. Proc. West. Soc. Weed Sci. (in press). Crose, J. A., M. R. Manuchehri, K. E. Cole, R. Rupp, B. Lindenmayer, and D. Cummings. 2018. Horseweed Management in Oklahoma Winter Wheat. Western Soc. Weed Sci. 71:34. Manuchehri, M.R., T. A. Baughman, and A. R. Post. 2017. Grassy Weed Management in Oklahoma Winter Wheat. Weed Sci. Soc. Am. Abs. 57:56. Manuchehri, M. R., J. A. Crose, K.E. Cole, R.N. Rupp, B. Lindenmayer, D.C. Cummings. 2018. Horseweed Management in Oklahoma Winter Wheat. Weed Sci. Soc. Am. Abs. 58:38. Manuchehri, M. R., G. Strickland, K. E. Cole, J. A. Crose. 2018. Rescuegrass Management in Oklahoma Winter Wheat. Western Soc. Weed Sci. 71:32. Ogden, G. K., M. R. Manuchehri, and A. C. Hixson. 2017. Pyroxasulfone Weed Management Systems in Oklahoma Winter Wheat. Proc. West. Soc. Weed Sci. 70:4. Ogden, G. K., M. R. Manuchehri, A. C. Hixson, K. E. Cole, J. A. Crose. 2018. The Development and Management of ACCase Resistant Italian Ryegrass in Oklahoma. Western Soc. Weed Sci. 71:35. Rauch T. A., and J.M. Campbell. 2017. Broadleaf Weed Control in Winter Wheat with Bicyclopyrone Plus Bromoxynil. Proc. West. Soc. Weed Sci. (in press). Rauch, T.A. and J. M. Campbell. 2017. Italian ryegrass control with pyroxasulfone/carfentrazone in wheat. Research Prog. Report. Western Soc. Weed Sci. 79. Rauch, T.A. and J. M. Campbell. 2017. Mayweed chamomile control in winter wheat. Research Prog. Report. Western Soc. Weed Sci. 86. Rauch, T.A. and J. M. Campbell. 2017. The effect of disturbance on Italian ryegrass control with pyroxasulfone in winter wheat. Research Prog. Report. Western Soc. Weed Sci. 95. Rauch, T.A. and J. M. Campbell. 2017. Rattail fescue control in winter wheat. Research Prog. Report. Western Soc. Weed Sci. 89. San Martin C., D. Long, J. Gourlie J. and, J. Barroso. 2018. Effect of fallow management on weed infestation. Proc. West. Soc. Weed Sci. (in press). San Martin C., D. Long, J. Gourlie, and Barroso J. 2018. Effect of intensified wheat-based cropping systems on weed infestation. Proc. West. Soc. Weed Sci. (in press).

Impact Statements

Grower and industry awareness of herbicide resistance continued to increase in 2017 through a variety of presentations and articles in the popular press and through Timely Topic posts on the Wheat and Small Grains Website (smallgrains.wsu.edu). Wheat growers were provided with two new decision tools to help them make more informed decisions on herbicide use for the control of troublesome weeds. Growers were also provided with efficacy and crop safety information for newer herbicide products in wheat.

Date of Annual Report: 05/10/2019

Report Information

Annual Meeting Dates: 03/11/2019 - 03/11/2019
Period the Report Covers: 10/01/2017 - 09/30/2018

Participants

Barroso, Judit (judit.barroso@oregonstate.edu) – Oregon State University;
Campbell, Joan (jcampbel@uidaho.edu) - University of Idaho;
Creech, Cody (ccreech2@unl.edu) - University of Nebraska;
Creech, Earl (earl.creech@usu.edu) - Utah State University;
Hulting, Andy (Andrew.hulting@oregonstate.edu) - Oregon State University;
Kumar, Vipan (vkumar@ksu.edu) - Kansas State University ;
Lehnhoff, Erik (lehnhoff@nmsu.edu) - New Mexico State University;
Lyon, Drew (drew.lyon@wsu.edu) - Washington State University;
Mallory-Smith, Carol (carol.mallory-smith@oregonstate.edu) - Oregon State University;
Manuchehri, Misha (misha.manuchehri@okstate.edu) - Oklahoma State University;
Morishita, Don (don@uidaho.edu) - University of Idaho;
Ransom, Corey (corey.ransom@usu.edu) - Utah State University;
Rauch, Traci (trauch@uidaho.edu) - University of Idaho;
Roering, Kyle (kyle.roering@oregonstate.edu) - Oregon State University;
Seipel, Tim (timothy.seipel@montana.edu) - Montana State University;
Thompson, Curtis (cthompso@ksu.edu) - Kansas State University;
Young, Steve (steve.young@usu.edu) - Utah State University;
Westra, Phil (philip.westra@colostate.edu ) - Colorado State University

Brief Summary of Minutes

Judit Barroso, Chair, called the meeting to order at 3:00 pm. Attendance sheet was passed and attendees introduced themselves.

Presentation from Bill Whitacre (Policy Advisor for Western Governors’ Association):

The meeting was initiated with an update from Bill Whitacre. Major topics addressed included:

Biosecurity & Invasive Species Initiative
- Launched in July – ends in June
- Workshops – website (westgov.org) – initiative page
- Webinars
- Initiative Deliverables
  - Cheatgrass/Invasive annual grasses
  - Grazing practices
  - Biocontrol
- Invasive Species Data Mobilization Campaign
  - Improve invasive species occurrence data

Update from Mike Harrington (Director of Western Association of Agricultural Experiment Station Directors, Colorado State University):

The next update was from Mike Harrington. He provided a Multistate Committee Update.

Multistate Committee Update
- NIFA in the Federal Budget – President’s budget cuts 22 programs
- Changes in AFRI Programs – new programs focus on collaborations, RFA will soon be available for Sustainable Ag Systems Program
- New initiatives – single request 200 M increase in NIFA budget

Impact Reporting
- Output vs. Impacts
- What is an impact statement? = So what? Who cares?

Update on seeding direction study:

Unfortunately, Andrew Kniss could not attend the meeting due to his Presidential responsibilities. Judit will contact him in there is an update further than what we discussed in the meeting.

What we learned
- An effect was not observed with brome
- Carol aw something with ryegrass
- Andrew, Joan, and Judit lost trials

Now what? Publish something in Weed Tech Notes?

Discussion of feral rye collections:

Not much done. Seems to be a low priority

Phil will talk to Todd Gaines about his possible involvement

New collection this spring?

Do we need funding in order to increase prioritization? CPPM?

WERA-77 Priority Discussion:

What are our priorities?
- Need individual’s to lead projects that they are passionate about
- Do we need a social media platform for our group?
- Misha will incorporate these ideas in the 2020 meeting so look for her emails!

Other business:

The 2020 meeting will take place on Monday, March 2, 2020 in Maui, Hawaii. Time TBD, but likely at the same 3 PM time.

Misha Manuchehri will be collecting the state reports (due 6 weeks from the meeting).

Selection of new secretary/chair elect:

Vipan Kumar volunteered to be the new secretary/chair elect for next year. All the meeting participants agreed. Consequently, next year (2020) Misha Manuchehri will organize and conduct the meeting and Vipan Kumar will take notes and file the annual report.

The meeting adjourned at 4:30 pm.

Accomplishments

IDAHO REPORT Joan Campbell, Principle Researcher; Traci Rauch, Senior Research Specialist; and Don Morishita, Extension Weed Scientist. Plant Science Department, University of Idaho, 875 Perimeter Dr. MS 2333, Moscow, ID 83844-2333; 208-885-7730; <a href="mailto:jcampbel@uidaho.edu">jcampbel@uidaho.edu</a> Objective 1. Results. Using GPS, Italian ryegrass seed was collected in the same locations as in a 2006/2007 herbicide-resistant survey. Italian ryegrass samples were collected in 2017 and 2018. Samples not collected due to the cropping rotation (3 year) will be collected in 2019. Currently, 94 samples have been collected. Seed was collected by hand in the center of the infestation in each field. Seeds from each sample along with a known susceptible biotype are screened in the greenhouse against herbicides used in our area to control Italian ryegrass. Untreated plants are included from each sample. For 2017, no resistant samples were found for Zidua, Dual Magnum, Outlook or glyphosate. Axiom resistance is very low but screening for the group 15 herbicides is still incomplete at this point. Axial XL resistance is near 50% while PowerFlex and Osprey resistance is widespread (<90%). The non-selective group 1 herbicides with resistance includes:  Shadow (clethodim) (10%)< Poast (60%)<Assure II (80%). Objective 1. Outcomes/Impacts. Identifying Italian ryegrass changes in herbicide resistance overtime aids growers in understanding how their weed control management practices, including tillage and crop and herbicide rotation, have altered the makeup of the population. Objective 2. Results. In winter wheat, Italian ryegrass control with Anthem Flex at the highest rate applied preplant was similar to preplant Anthem Flex followed by spring applied Anthem Flex. A winter wheat/Italian ryegrass control study evaluated Zidua and Anthem Flex at the highest labeled rates with the following application times:  pre-fertilization (shank applied dry fertilizer), post fertilization, postplant no germination and postplant germinated wheat. Italian ryegrass control was improved with Anthem Flex versus Zidua at all timings due to a higher rate of pyroxasulfone. Axiom did not control Italian ryegrass and is most likely due to a resistant population. This study is being repeated in 2019. Rattail fescue was controlled 89 to 98% with Axiom, Zidua, and Anthem applied postplant preemergence in the fall alone or in combination with spring applied PowerFlex, Maverick and Everest. PowerFlex and Maverick alone only suppressed rattail fescue, while Everest controlled rattail fescue 90%. This study will be repeated in 2019. Downy brome was controlled 91% or greater with Zidua, Anthem Flex and Axiom alone or combined with Osprey Xtra. Osprey Xtra alone did not control downy brome. Downy brome was controlled 91% or better with Axiom, Zidua, and Anthem applied postplant preemergence in the fall alone or in combination with spring applied PowerFlex, Maverick and Everest. Everest alone did not control downy brome (78%). In the greenhouse, Italian ryegrass was planted into dry conditions and sprayed with Zidua. Pots were irrigated with 0.3 inch of rainfall at 0, 8,15, 22,29, 36, and 43 DAT. Pots with untreated plants were included. The study is arranged as a randomized complete block with 4 replications. It is currently ongoing and plant emergence, height and biomass will be measured. Objective 2. Outcomes/Impacts: Zidua (group 15) was registered for annual grass control, including Italian ryegrass and rattail fescue, in winter and spring wheat in spring 2014. Zidua registration has aided in control of group 1 and 2 resistant Italian ryegrass. Very few herbicides control rattail fescue. Zidua and Anthem treatments controlled rattail fescue 89-97% in 2018.Winter wheat yield was not reduced by Zidua when 0.5 inch of sprinkler irrigation was applied immediately after planting and spraying on the same day (worst-case scenario). Wheat had minimal injury in 11 conventional-tilled (chisel plowed/field cultivated) sites and in seven direct-seed locations. U of I studies were instrumental in implementing Zidua label changes including an increased use rate and a preplant application time in winter wheat. These label changes have aided growers by giving them more options to improve weed efficacy. Anthem Flex also was registered in wheat fall 2014. Our Anthem Flex studies were useful to FMC when drafting rates and timings for their label. This information will help growers use these products safely and effectively to control grass weeds with minimal crop injury. These registrations provide needed tools to help control herbicide resistant weeds, especially Italian ryegrass. Objective 3. Results: A field trial was established at UI research farms near Moscow and Genesee to examine tillage effects on rattail fescue. Winter wheat was direct-seeded in fall 2013. The rotation is winter wheat- spring wheat- spring chickpea. Tillage initiated in the fall 2014 included fall disc or chisel plow followed by spring field cultivation. A no-tillage treatment is included as a control. Heavy harrow replaced disc in year 2 and 3. The tillage was performed all 3 years, 2 years or 1 year for a total of 7 tillage regimes. Spring chickpea was seeded in 2016. Rattail fescue populations were low in the chickpea year of the tillage comparison study. The weed was found only in no-till and the one year of chisel plow. Tillage treatments were applied and winter wheat was planted fall 2016 for the third year of the study. Winter wheat yield was confounded by standing water at Moscow and rodent damage at Genesee. This is currently being repeated. Objective 3. Outcomes/Impacts: Knowledge of cultural controls, crop rotation and tillage is limited for rattail fescue control. Current information is speculative at best. Herbicide usage is the only known research-based tool for rattail fescue control. Tillage is important but research on how invasive and how often is unknown. This data will help growers take an integrated weed management approach to reducing rattail fescue and increasing crop yield. Objective 4. Results: Two new broadleaf weed control herbicides in winter wheat were evaluated. Talinor (bicyclopyrone/bromoxynil) was combined with grass herbicides that require a fertilizer adjuvant. The Talinor label currently does not allow applications with ammonium sulfate (AMS), a fertilizer. Talinor combined with PowerFlex or Osprey plus UAN (fertilizer) did not reduced grain yield or test weight compared to PowerFlex or Osprey alone plus UAN. Talinor was also combined with foliar fungicides to evaluate wheat tolerance. No visual injury or yield and test weight reduction were found with Tilt, Priaxor, Quilt Xcel, Nexicor, Approach and Trivapro. In winter wheat, Quelex (halauxifen/florasulam) alone or combined with Huskie, Talinor, and Starane Ultra controlled mayweed chamomile 95 to 96% which was similar to WideMatch or Starane Flex alone (91&94%). In spring wheat, Quelex alone controlled common lambsquarters 86% which was similar to Huskie and WideMatch combined with Affinity Broadspec and Affinity TankMix (99%). A new postemergence grass herbicide, Osprey Xtra (mesosulfuron/ thiencarbazone) controlled rattail fescue (86-96%) better than Everest (20%) and Osprey (61%). Osprey controlled downy brome better than Osprey Xtra. Studies in 2019 will continue to evaluate these new herbicides for weed control efficacy. Objective 4. Outcomes/Impacts: Examining tolerance and efficacy of newly registered and soon-to-be registered herbicides is critical to the development of unbiased information on the use of these products by Idaho wheat growers. Evaluating combinations of fungicides with herbicides for crop response and weed control is also important. This data assists in timely federal registration of new compounds. Herbicides with new and different modes of action are necessary to reduce or stop the development of herbicide resistant weeds. Talinor and Quelex may be options for possible control of herbicide resistant broadleaf weeds. Objective 5. Results: Suspected-resistant weed seed samples collected from research plots and submitted by growers, fieldmen, and industry representatives were screened in the greenhouse. The weed seed samples were sprayed with herbicides at twice the labeled rate. Susceptible plants were included to verify spray coverage and rate. Seeds were counted at planting with preemergence herbicides and plants counted at emergence with postemergence herbicides. Untreated plants were included from each sample. Resistance was evaluated on plant survival and vigor compared to the untreated. Two interrupted windgrass seed samples were treated with five herbicides. No sample was resistant to Shadow (clethodim) or glyphosate. Samples were resistant to PowerFlex, Osprey, and Everest (group 2). Three downy brome seed samples were screened with six herbicides. No sample was resistant to Shadow or glyphosate Samples were resistant to PowerFlex, Beyond, Olympus, and Maverick (group 2). A mayweed chamomile seed sample was treated with six herbicides. The sample was resistant to Affinity BroadSpec and Ally Xtra (group 2). It was not resistant to Huskie, Lorox, Talinor and WideMatch. A common lambsquarters seed sample was treated with five herbicides. The sample was susceptible to all herbicides (Pursuit, Spartan, Valor, Sharpen, and metribuzin). Objective 5. Outcomes/Impacts: Screening weed seed samples enables growers to combat herbicide resistance by adjusting their weed control approach so that it includes rotating chemicals, changing crop rotations, and implementing other cultural practices. Objective 6. Results: Project personnel participated in cereal schools in north Idaho in January. Research information was presented at the Western Society of Weed Science meeting in March. Cereal research was also presented at field days in June and July. Objective 6. Outcomes/Impacts: Information presented at cereal schools, field tours, and extension meetings will aid growers in making the best economic and ecological decisions for weed control in their wheat production systems. KANSAS REPORT Vipan Kumar, Weed Scientist Kansas State University, Agricultural Research Center, Hays, KS 67601. <a href="mailto:vkumar@ksu.edu">vkumar@ksu.edu</a> Research: Downy brome control in CoAxium™ winter wheat. Field experiment was conducted at Kansas State University Agricultural Research Center near Hays, KS to evaluate Aggressor herbicide for downy brome control in CoAxium™ winter wheat. CoAXium™ wheat is a new herbicide-resistant (non GMO) wheat technology that contains the AXigen™ trait for resistance to the ACCase (Group 1) class of herbicides. Aggressor is the herbicide labeled for use on CoAXium wheat and contains the active ingredient quizalofop-p-ethyl. POST treatments of Aggressor were applied in fall (Nov 6, 2017) and spring (Mar 28, 2018) using a CO2-operated backpack sprayer calibrated to deliver 14 GPA at 40 psi. All Aggressor treatments were applied with NIS adjuvant. Field site was uniformly infested with natural population of downy brome. Downy brome plants were at 3 to 4-lf stage at fall application timing and 2 to 3 tiller stage at spring application timing. No visible injury to winter wheat was observed with any of the fall or spring applied Aggressor treatments. Aggressor applied at 8 to 10 fl oz/a in fall provided an excellent, season-long control (96% prior to wheat harvest) of downy brome. Control with Aggressor (8 fl oz/a) applied in spring was slightly lower than fall application timing, and did not exceed 91% at final rating. Lower control observed with spring application of Aggressor was possibly due to presence of some dormant seedlings of downy brome at spring timing. Fall treatments of Aggressor (8 or 10 fl oz/a) showed slight increase in wheat yields compared with spring application timings.     Downy brome control in Clearfield® winter wheat. A field study was conducted at Kansas State University Agricultural Research Center near Hays, KS to evaluate PRE alone, POST alone and PRE followed by (fb) POST herbicide treatments for downy brome control in Clearfield® winter wheat. PRE alone programs included Zidua (pyroxasulfone) at 3 oz/a, Olympus (propoxycarbazone-sodium) at 0.6 oz/a, and AnthemFlex (pyroxasulfone + carfentrazone) at 3 fl oz/a; POST alone treatments were Powerflex HL (pyroxsulam) at 2 oz/a and Beyond (imazamox) at 5 fl oz/a; PRE fb POST treatments were Zidua (1.5 oz/a) fb Beyond (5 fl oz/a), Olympus (0.6 oz/a) fb Beyond (5 fl oz/a), and AnthemFlex (3 fl oz/a) fb Beyond (5 fl oz/a). All PRE treatments were applied on Sep 29, 2017 and POST treatments were applied on Mar 28, 2018 using a CO2-operated backpack sprayer equipped with four nozzle tips and calibrated to deliver 14 GPA at 40 psi. Data on percent downy brome control were collected on biweekly interval after POST applications. The study site had uniform, natural population of downy brome. POST applications of Beyond herbicide was made by using NIS adjuvant. All PRE alone and PRE fb POST treatments provided effective control (91 to 99%) of downy brome at final rating (prior to wheat harvest). Downy brome control with POST alone treatments was moderate and did not exceed 83% at final rating. No significant differences in wheat yields were observed among these herbicide programs. Response of Kansas feral rye populations to Beyond and Aggressor. Feral rye is a problematic winter annual grass weed species in Kansas winter wheat production. A random collections of feral rye seeds were initiated in summer 2018 from wheat fields in central Kansas. Seeds of nine feral rye populations were randomly collected with GPS coordinates at the time of wheat harvest. Greenhouse experiments were conducted at Kansas State University Agricultural Research Center near Hays, KS to determine the response of those populations to Aggressor (quizalofop-p-ethyl) and Beyond (imazamox) herbicides. Seedlings of population were grown in 4- by 4-in plastic pots containing commercial potting mixture. At 3- to 4-lf stages, feral rye seedlings were separately treated with various doses (ranging from 0.25X to 4X) of Aggressor (1X = 8 fl oz/a) and Beyond (1X = 5 fl oz/a) in cabinet spray chamber. NIS and MSO adjuvants were included with Aggressor and Beyond herbicide doses as per each label guidelines. Percent visual control of those treated seedlings were assessed at 7, 14, and 21 days after treatment (DAT). For majority of the feral rye populations tested, control with Beyond herbicide was inconsistent. Percent control ratings for feral rye at 21 DAT of Beyond at field-use rate (1X=5 fl oz/a) ranged from 75 to 80 % for those nine populations. In contrast, the Aggressor provided effective control (95 to 100%) of all nine feral rye populations even at half of the labeled-use rate (4 fl oz/a) 21 DAT. Control ratings of all nine populations were consistent with the shoot dry weight reductions with various Beyond and Aggressor herbicide rates tested.   Impact Statement: Information obtained from these research projects was delivered to Kansas wheat growers through a variety of presentations and popular press articles on K-State Agronomy Extension e-update (<a href="https://webapp.agron.ksu.edu/agr_social/">https://webapp.agron.ksu.edu/agr_social/</a>). Results were also shared with wheat growers, county ag agents and crop consultants through Weed Schools conducted across western Kansas. OKLAHOMA REPORT Misha Manuchehri, Extension Weed Specialist, Department of Plant and Soil Sciences, Oklahoma State University, 371 Agricultural Hall, Stillwater, OK 74078. 405-744-9588. <a href="mailto:misha.manuchehri@okstate.edu">misha.manuchehri@okstate.edu</a> Identification and Management of ACCase Resistant Italian Ryegrass Axial XL resistant Italian ryegrass biotypes are suspected in Oklahoma; however, only plants with an increased tolerance have been identified in greenhouse screenings. The use of group 15 herbicides may improve the control of these difficult-to-manage plants. Several studies were conducted throughout Oklahoma throughout the 2016-17, 2017-18, and 2018-19 seasons to evaluate the use of Zidua (pyroxasulfone), Anthem Flex (pyroxasulfone + carfentrazone), and Axiom (flufenacet+metribuzin) to control Italian ryegrass. Control was at least 95% for all treatments that included pyroxasulfone DPRE or VEPOST or pinoxaden VEPOST. Similar control was achieved with pyroxasulfone + carfentrazone and flufenacet + metribuzin. Timely rains and proper herbicide to soil contact contributed to the success of these treatments. A study evaluating the impact of residue on performance of these group 15 herbicides is currently being carried out. IMPACTS Growers in Oklahoma battling Italian ryegrass can receive nearly season long control of the weed with DPRE applications of Zidua, Anthem Flex, or Axiom as long as products have been adequately incorporated with rainfall. Horseweed Management in Winter Wheat Traditional broadleaf postemergence herbicide treatments vs. those containing Quelex (florasulam + halauxifen), Sentrallas (thifensulfuron methyl + fluroxypyr), and Talinor (bicyclopyrone + bromoxynil) were compared when applied to multiple growth stages of horseweed (5, 10, and 15 cm) throughout Oklahoma during the 2016-17 and 2017-18 field seasons. Across all site years, halauxifen + florasulam achieved greater than 90% control with the exception of two treatments at Altus in 2018 and one treatment at Ponca City in 2018. Thifensulfuron + fluroxypyr + dicamba achieved greater than 90% control at all site years except at Ponca City in 2017. Halauxifen + florasulam and thifensulfuron + fluroxypyr were both effective at controlling a wide range of horseweed rosette sizes across all locations while control with other treatments varied depending on presence of herbicide resistance, weed size at time of application, and tank mix partner. Finally, no visual crop injury was observed following any treatment. IMPACTS Halauxifen + florasulam and thifensulfuron + fluroxypyr are both effective at controlling a wide range of horseweed rosette sizes across Oklahoma. Successful horseweed control in winter wheat aids in ease of harvest, increased grain quality, and suitable planting conditions for double crops. Rescuegrass Management in Winter Wheat Rescuegrass is one of the most challenging winter annual weeds to manage in Oklahoma. There are few herbicides labeled for rescuegrass control in winter wheat and for the ones that are labelled, control is often inconsistent. To evaluate herbicide systems for rescuegrass management, several trials were conducted throughout Oklahoma during the 2017-18 and 2018-19 field seasons. At both Altus and Yukon, rescuegrass control was the highest following fall postemergence applications of imazamox. At Altus, imazamox + AMS + NIS or MSO controlled rescuegrass 93 to 96%. At Yukon, imazamox + AMS + MSO achieved 69% control while imazamox + AMS + NIS controlled rescuegrass 56%. All other treatments at Yukon performed poorly as a six inch rain event followed PRE treatments and control with pyroxsulam was low (<10%). Conversely, at Altus, PRE treatments of glyphosate alone or glyphosate + flucarbazone-sodium or propoxycarbazone-sodium achieved 64 to 69% control. Preemergence treatments of glyphosate alone or glyphosate + flucarbazone-sodium or propoxycarbazone-sodium + pyroxsulam achieved 80 to 84% control. CoAXium Systems for Management of Feral Rye and Rescuegrass Applications of Aggressor herbicide + NIS, COC, MSO, and/or AMS were applied to feral rye in the fall and/or spring of the 2017-18 and 2018-19 field seasons. Fall treatments alone and a fall treatment followed by a spring treatment achieved the highest levels of control (nearly 100%); however, all treatments controlled these plants at a greater level than other, existing herbicide options. Still, in Oklahoma, the primary recommendation to manage these weeds is to rotate out of winter wheat or delay planting if rescuegrass is the target weed species. IMPACTS The cost of successfully managing feral rye and rescuegrass with herbicides in Oklahoma is typically not worth the investment. If primary weed species include feral rye or rescuegrass, rotation out of a winter cereal is highly recommended. Tillage or glyphosate burndown follow by a delayed planting date also can be a successful strategy in managing rescuegrass populations. OREGON REPORT Judit Barroso, Weed Scientist. Crop and Soil Science Department, Columbia Basin Agricultural Research Center, Oregon State University. (541)2784394. <a href="mailto:judit.barroso@oregonstate.edu">judit.barroso@oregonstate.edu</a> Research: Weed responses to fallow management in Pacific Northwest dryland cropping systems: A two-year rotation of summer fallow (SF)/winter wheat (WW) is the most common cropping system in low precipitation areas of the U.S. Pacific Northwest (PNW). In SF, multiple tillage operations are used to manage weeds and maximize soil water storage and potential WW yield. Reduced tillage fallow (RTF) is an alternative to SF that leaves>30% of the previous crop’s residue on the surface. A four-year (2014–18) field study was conducted to evaluate the influence of SF and RTF on weed species density, cover and composition in dryland WW; determine if changes in these weed infestation attributes have any influence on crop density and yield; and evaluate economic costs of each type of fallow management. The experimental design was randomized complete block with four replications where each phase of SF/WW and RTF/WW rotations was present every year. Individual plots of WW were divided into a weedy sub-plot with no weed control, general area with chemical weed control, and weed-free sub-plot where weeds were manually removed. Infestations of annual grass and other weeds in weedy sub-plots increased throughout the study. Grass weed cover, consisting mainly of downy brome (Bromus tectorum L.), and total weed cover were significantly lower in WW following RTF than following SF in all years except 2018. Densities of grass and total weeds were similar in both fallow managements indicating that weed plants were larger in WW following SF than following RTF due to earlier or faster emergence. Grass cover differences were not found in general areas likely because of a reduced seedbank. When weeds were present, mean yield of WW was higher following RTF than SF indicating that weeds were less competitive in RTF. Impact Statement: Reduced tillage fallow could improve weed management in fallow/WW cropping systems of the PNW compared to SF/WW, particularly if the most problematic species are grasses. Effect of cropping system intensification on weeds in the semi-arid region of inland Pacific Northwest: Downy brome (Bromus tectorum L.) is a problematic weed for the conventional fallow/winter wheat (F/W) production system in the low precipitation-region (<350mm yr−1) of the Paciﬁc Northwest. A 4-yr ﬁeld experiment was conducted to determine if incorporating spring barley (B, Hordeum vulgare L.) or spring carinata (C, Brassica carinata A. Braun) into 3-yr crop rotations with W would beneﬁt weed management. The experimental design was a split-plot with four replications where each phase was present every year for the following rotations: 1) F/W, 2) F/W/B, and 3) F/W/C. Reduced tillage, consisting of a single undercutting operation with a wide-blade sweep, and herbicides were used to control weeds during the fallow period. The seeded plots were subdivided in three diﬀerent weed management areas: a weed-free area where weeds were pulled by hand, a weedy area with no weed control and a general area where weeds were chemically controlled. Weed density and cover per species and W yield were evaluated in each rotation. Grass cover and density after one and two complete cropping cycles were signiﬁcantly higher in F/W than in F/W/B and F/W/C. Reduction in density and cover of total weeds was found after two cycles. However, diﬀerences in community biodiversity were only found between F/W, and F/W/B or F/W/C in 2017. Winter wheat plots of F/W had more downy brome than F/ W/B or F/W/C indicating the greater capacity of the latter to control this weed. In 2018, the 3-yr rotation with barley had greater winter wheat grain yield compared with F/W when weeds were not present though weeds were more competitive in F/W/B. Impact Statement: Intensifying the F/W cropping system into a 3-yr crop rotation of W followed by spring barley or spring carinata may reduce weed infestations of winter annual grasses that are diﬃcult to control in W and the most competitive due to larger similarities in their life cycle with this crop. Downy brome (Bromus tectorum) and rattail fescue (Vulpia myuros) control with Osprey Extra in winter wheat. A field study was conducted at the OSU Columbia Basin Ag Research Center near Pendleton, OR to test the efficacy and tolerance of Osprey Xtra in combination with other herbicides on winter wheat for control of downy brome (Bromus tectorum) and rattail fescue (Vulpia myuros). Osprey Xtra is a Group 2 herbicide (ALS inhibitors) containing mesosulfuron-methyl, thiencarbazone-methyl and mefenpyr-diethyl. Crop damage was low for all treatments at all evaluation times. The Zidua (Fall pre-emerge) + Osprey Xtra (Spring) treatment had the best downy brome control (93%), followed closely by Axiom (Fall pre-emerge) + Osprey Xtra (Spring) (86%). Axiom (Fall pre-emerge) showed the least downy brome control of all treatments. There was no significant difference among treatments for rattail fescue, with Zidua (Fall pre-emerge) and Zidua (Fall pre-emerge) + Osprey Xtra (Spring) showing the best control (69%). Zidua (Fall pre-emerge) + Osprey Xtra (Spring) (92 bu/A) was the only treatment to have a significant difference in yield with the untreated plots (34 bu/A). However, all treatments had at least double the amount of yield compared to the control plots. Impact Statement: Collaborating with the industry to understand how new herbicides work in the different regions is critical to provide growers with unbiased information. Growers are normally very interested in new products that can help them with the day-to-day problem of resistant weeds. UTAH REPORT Earl Creech, Extension Agronomist; Corey Ransom, Extension Weed Scientist; Steve Young, Weed Scientist. Plants, Soils & Climate Department, Utah State University, 4820 Old Main, Logan, UT 84322; 435-797-0139; <a href="mailto:steve.young@usu.edu">steve.young@usu.edu</a> Research: Kochia-cover crop study – Year 2 (2019) The objective of this study is to evaluate the influence of cover crops, and planting dates and rates on kochia populations in wheat fields of Utah and southern Idaho. Similar to Year 1 (2018), planting dates and rates will be assessed as secondary tactics (e.g., early or late season plantings – avoidance, size advantage; high rates – resource use, competitive advantage) against kochia in combination with cover crops as a primary tactic. Wheat allelopathy study – Year 1 (2019) Many plants are reported to naturally produce secondary compounds that can have a deleterious effect on neighboring vegetation, also known as allelopathy. While not lethal, this allelopathic effect by a plant can also provide a competitive advantage against weed species. Unknown is to what extent allelopathy in wheat prohibits species of weeds. Therefore, our hypothesis is that wheat cultivars from the Pacific Northwest will stop weed species seed from germinating. The objective is to determine the allelopathic effect of several wheat cultivars on the growth and development of weed seed. Extension: Kochia-cover crop study – Year 2 (2019) Similar to Year 1 (2018), specific methods for disseminating results will include: 1) establishing research at university field sites, 2) conducting field days in partnership with local growers, crop advisors and seed dealers (Utah Seed), 3) updating county educators, regional specialists, and private crop advisors at in-service meetings, 4) uploading findings on university extension and private organization websites, 5) presenting findings at local and regional meetings and conferences, 6) announcing project findings in local newsletters, newspapers for growers, and during statewide and regional speaking engagements, and 7) integrating research findings into course teachings that target next generation ag-professionals. Impacts: Kochia-cover crop study – Year 2 (2019) Outcomes: Growers will benefit from our project through increased understanding and directly implementable results. A survey will be administered at the in-service meetings to determine what changes have occurred in awareness, knowledge, attitude, or skills related to learning and resulting actions, if any. WASHINGTON REPORT Drew J. Lyon, Extension Weed Scientist; Rachel J. Zuger, Research Technician; Ian C. Burke, Weed Scientist. Crop and Soil Sciences Department, Washington State University, Pullman, WA 99164-6420; 509-335-2961. <a href="mailto:drew.lyon@wsu.edu">drew.lyon@wsu.edu</a> Research: Evaluation of Aggressor herbicide for the control of feral rye in the CoAXium wheat production system. The CoAXium™ wheat production system was recently developed by the Colorado Wheat Research Foundation, Inc., Limagrain Cereal Seeds, LLC and Albaugh, LLC. AXigen™ is the non-GMO trait in wheat that confers tolerance to the ACCase inhibitor (Group 1) herbicide Aggressor™ (quizalofop-P-ethyl). The AXigen trait will be made available to both private and public breeders and was one of the reasons we were interested in evaluating the system. Aggressor is labelled to control annual grassy weeds, such as downy brome, jointed goatgrass and feral rye that are problematic in the low to intermediate rainfall zones of eastern WA. On October 17th, the trial area was direct-seeded with a John Deere 9400 hoe drill with openers on a 7-inch spacing and a planting depth of 2.0 inches. The area was seeded at the rate of 120 lb/A, 107 lbs CoAxium winter wheat plus 13 lbs cereal rye. The ground was fertilized with 100 lb N per acre from dry urea on March 21, 2018. The soil at this site is a Palouse silt loam with 4.2% organic matter and a pH of 5.0. Early postemergence treatments were applied on April 11th. At the time of application, wheat was at the 2-tiller stage and was 7 inches tall. Cereal rye had one node and was 14 inches tall, which is larger than the 1- to 4-inch height prescribed on the label. Late postemergence treatments were applied on May 4th. At the time of application, wheat had one node and was 14 inches tall. Cereal rye had 3 nodes and was 22 inches tall. Both applications were made with a CO2-powered backpack sprayer set to deliver 15 gpa at 47 psi at 2.3 mph. The Aggressor label only allows applications to be made on 1- to 4-inch tall cereal rye, hence our applications were made outside the label guidelines. Despite the late applications, early spring applications of Aggressor were highly effective for cereal rye control. There were no significant differences among the three rates evaluated, and no differences seen between NIS and MSO. The late spring application was also highly effective. Only Aggressor treatments applied at 8.0 or 10.0 fl oz/A and tank mixed with 1.0% MSO had a few plants that escaped control. There were no significant differences in yield among the Aggressor treatments and the mean was 86 bu/A. The yield in the nontreated check plots was 85 bu/A with 15% foreign material as cereal rye. Aggressor appears to be highly effective for the control of cereal or feral rye in the high rainfall zone. It will be important to evaluate the CoAXium wheat production system in the intermediate to low rainfall zones under more stressful environmental conditions. Control of Bromus spp. (Bromus tectorum L. and Bromus sterilis L.) in Winter Wheat. Downy brome (Bromus tectorum) continues to be a problematic and widespread weed in inland PNW wheat-fallow rotations. Acetolactate synthase inhibitor resistance continues to spread, and there are very few herbicide options remaining. Sterile brome (Bromus sterilis) is another bromegrass invading wheat fields in intermediate and low rainfall zones. Our objective was to identify one or more herbicide treatments with different herbicide modes of action for management of downy brome and sterile brome. Two winter wheat studies were conducted in the intermediate to low rainfall (< 17” rainfall annually) area in 2018 at Ewan and Anatone, WA. Visual control was assessed for both sites. The combination of both a fall applied delayed-PRE and a spring applied POST herbicide treatment did not impact the efficiency of Bromus spp. control at either site. All delayed-PRE treatments, except propozycarbazone and sulfosulfuron + metribuzin, controlled the Bromus spp. with greater than 65% control compared to the nontreated control. Yield for both sites was combined and increases in yield were observed for pyroxasulfone + metribuzin (780 kg ha-1), pyroxasulfone + diclofop (850 kg ha-1), pyroxasulfone + metribuzin + diclofop (840 kg ha-1), diclofop (770 kg ha-1), and metribuzin + diclofop (770 kg ha-1). The nontreated control yielded 640 kg ha-1. Pyroxasulfone, with and without either metribuzin of diclofop, appears to be an effective PRE herbicide for both Bromus tectorm and Bromus sterilis when applied delayed-PRE. Impact Statement: Grower and industry awareness of herbicide resistance continued to increase in 2018 through a variety of presentations and articles in the popular press and through Timely Topic posts and podcast episodes on the Wheat and Small Grains Website (<a href="http://smallgrains.wsu.edu/">smallgrains.wsu.edu</a>). Wheat growers were provided with a <a href="http://herbicidecomparison.cahnrs.wsu.edu/">new decision tool</a> to help them make more informed decisions on herbicide use for the control of troublesome weeds. Growers were also provided with efficacy and crop safety information for newer herbicide products in wheat.

Publications

Peer Review Publications: Barroso J, Gourlie J, Lutcher L, Mingyang L, Mallory-Smith C. 2018. Identification of glyphosate resistance in Salsola tragus in Northeastern Oregon. Pest Management Science 74:1089-1093. Lawrence NC, Hauvermale AL, Burke IC. 2018. Downy Brome (Bromus tectorum) vernalization: variation and genetic controls. Weed Sci. 66:310-316. Lyon DJ, Swanson ME, Young FL, Coffey T. 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, Kniss AR, Lyon DJ, Zemetra RS. 2018. Jointed goatgrass (Aegilops cylindrica): A review. Weed Sci. 66:562-573. Reardon CL, Wuest SB, Melle CJ, Klein AM, Williams JD, McCallum J, Barroso J, Long DS. 2019. Soil enzyme activity under minimum and conventional tillage wheat-fallow cropping systems. Soil Science Society of American Journal (Accepted (01/15/2019), In Press). San Martin C, Long D, Gourlie JA, Barroso J. 2018. Suppression of downy brome by reduced tillage fallow in dryland winter wheat. PloS One 13(9):1-17. San Martín C, Lyon DJ, Gourlie J, Wetzel HC, Barroso J. 2018. Weed control with bicyclopyrone + bromoxynil in wheat. Crop Forage Turfgrass Manage. 4:180011. doi:10.2134/cftm2018.02.0011. San Martín C, Long D, Gourlie JA, Barroso J. 2019. Spring crops in three year rotations reduce weed pressure in winter wheat. Field Crops Research 233, 12-20. Spring, JF, Thorne ME, Burke IC, Lyon DJ. 2018. Rush skeletonweed (Chondrilla juncea) control in Pacific Northwest winter wheat. Weed Technol. 32:360-363. Walsh MJ, Broster JC, Schwartz-Lazaro LM, Norsworthy JK, Davis AS, Tidemann BD, Beckie HJ, Lyon DJ, Soni N, Neve P, Bagavathiannan MV. 2018. Opportunities and challenges for harvest weed seed control in global cropping systems. Pest Manag. Sci. 74:2235-2245. Extension Publications: Hauvermale AL, Race KN, Lawrence NC, Koby L, Lyon DJ, Burke IC. 2018. A mayweed chamomile growing degree day model for the Inland Pacific Northwest. (FS306E). Lyon DJ, Ball DA, Hulting AG. 2018. Rattail fescue: Biology and management in Pacific Northwest wheat cropping systems. (PNW613). Lyon DJ, Burke IC, Campbell JM. 2018. Integrated management of mustard species in wheat production systems. (PNW703). Manuchehri MR, Ogden G. 2018. Herbicide Programs for Italian Ryegrass Control in Oklahoma Winter Wheat, PSS-2791. Manuchehri MR. 2018. Herbicide Mixing Order. Oklahoma State University, PSS-2789. Manuchehri MR, Adcock M, Arnall DB. 2018. Rainfastness for Fallow and In-Season Winter Wheat Herbicides that have Postemergence Activity, L-468. Manuchehri MR, Arnall DB. 2018. How Does Soil pH Impact Herbicides. Oklahoma State University, PSS-2778. Peterson D, Kumar V. 2018. CoAXium Wheat and Aggressor Herbicide for Grass Weed Control. Kansas State University, eUpdate. Issue 719. November 7, 2018. Conference Presentations: Childers JT, Manuchehri MR, Kumar V, Liu R, Crose JA. 2019. Non-tolerant Wheat Response to Simulated Drift of Quizalofop-P-ethyl in Central Oklahoma. Proc. West. Soc. Weed Sci. 72:24 (in press). Liu R, Kumar V, Lambert T, and Manuchehri MR. 2019. Response of Kansas Feral Rye Populations to Imazamox and Quizalofop-P-ethyl. Proc. West. Soc. Weed Sci. 72:119 (in press). Ogden, G. K., M. R. Manuchehri, A. C. Hixson, K. E. Cole, J. A. Crose. 2018. The Development and Management of ACCase Resistant Italian Ryegrass in Oklahoma. Western Soc. Weed Sci. 71:35. Crose, J. A., M. R. Manuchehri, K. E. Cole, R. Rupp, B. Lindenmayer, and D. Cummings. 2018. Horseweed Management in Oklahoma Winter Wheat. Western Soc. Weed Sci. 71:34. Manuchehri, M. R., G. Strickland, K. E. Cole, J. A. Crose. 2018. Rescuegrass Management in Oklahoma Winter Wheat. Western Soc. Weed Sci. 71:32. Manuchehri, M. R., J. A. Crose, K.E. Cole, R.N. Rupp, B. Lindenmayer, D.C. Cummings. 2018. Horseweed Management in Oklahoma Winter Wheat. Weed Sci. Soc. Am. Abs. 58:38. Rauch T, Campbell J.  2018.  Rattail fescue and downy brome control in winter wheat with mesosulfuron plus thiencarbazone.  Western Society of Weed Science Proceedings 71:17. Wuest SB, Barroso J. 2019. Is volunteer wheat a serious weed in annual winter wheat production? Proceedings of the WSWS Annual Meeting. Denver, CO. Abstract.

Impact Statements

WSU: Wheat growers were provided with a new decision tool to help them make more informed decisions on herbicide use for the control of troublesome weeds. Growers were also provided with efficacy and crop safety information for newer herbicide products in wheat.