Brief Summary of Minutes of Annual Meeting

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.

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; jcampbel@uidaho.edu

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. misha.manuchehri@okstate.edu 

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. Judit.Barroso@oregonstate.edu 

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; steve.young@usu.edu 

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. drew.lyon@wsu.edu 

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 (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.

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).