Brief Summary of Minutes of Annual Meeting

Colorado State University We are focused this year on feral rye control with imazamox, trying to understand the interaction between rye vernalization and control in the field. We continue to work on gene flow issues between jointed goatgrass and winter wheat; this on-going research is being supported by a new grant proposal that was funded for 3 years. We are wrapping up the research that was funded by the National Jointed Goatgrass program. University of Nebraska In field studies conducted in the Nebraska Panhandle on feral rye, Clearmax provided similar to slightly better control of feral rye than Beyond herbicide. Clearmax also provided slightly better control of tumble mustard in one year when it was present with the rye (data not shown). In a 2006/2007 study conducted near Sidney, liquid fertilizer (32-0-0) was used at three rates (2.5, 25, and 50% v/v) with Beyond and Clearmax herbicides applied in the fall and spring. Herbicide treatments were applied in 10.9 gallons/acre of spray solution. The higher rates of fertilizer reduced feral rye control with Beyond, particularly the spring applications. However, feral rye control with Clearmax was not reduced with increasing fertilizer rates. Crop injury was slightly greater with Clearmax than with Beyond. In North Platte, a study that examined the effect of tillage method and burning in fallow to reduce jointed goatgrass in a winter wheat-fallow rotation has come to a close with the harvest of the final winter wheat crop this summer. The use of plowing with complete inversion almost eliminated jointed goatgrass by burying seed too deep to germinate. Burning significantly decreased the incidence of jointed goatgrass by destroying the seed on the surface. Disking was ineffective at decreasing the incidence of jointed goatgrass. The use of Clearfield wheat 'Above' combined with application of Beyond herbicide reduced the density of jointed goatgrass compared to tillage alone. Downy brome control was evaluated in 2006-2007 at North Platte. Best control was achieved with a fall application of Olympus at 0.9 oz/acre or a split fall/spring application of Olympus with 0.6 oz/acre followed by 0.6 oz/acre. Extension. Two NebGuides on winter annual grass weed control in winter wheat were updated 2007. The major changes involved adding new information on the use of the Clearfield production system to control these weeds. An article on the control of winter annual grass weeds in winter wheat was published in the UNL newsletter Crop Watch (cropwatch.unl.edu/archives/2007/crop5/wheat_weeds.htm). No specific extension programming focused on winter annual weeds in winter wheat in 2007. Texas A&M University Several weed management trials for grass weeds were initiated in the Rolling Plains and Blacklands of Texas. These research trials included several relatively new chemistries that are focused on various grass weeds. Weed management trials in the Blacklands focused on managing Italian ryegrass with several new and older herbicides. Finesse Grass and Broadleaf® was evaluated for efficacy on Italian ryegrass at several different rates of the active ingredients and also several rates of liquid fertilizers. Overall efficacy of this product was marginal in 2006 but was acceptable in 2007. The increased efficacy was associated with two factors. First the Italian ryegrass plants were smaller and the weeds were actively growing in 2007. Olympus Flex®, Osprey®, and Axial® were evaluated for Italian ryegrass and wild oat control at two locations. All these herbicides provide sufficient control of 1-2 tiller Italian ryegrass and wild oats. However, the efficacy of the Osprey and Olympus Flex was lower than Axial on larger plants in the plots. Todd Baughman evaluated pyroxsulam (Dow Agro-Science) for managing rescuegrass in wheat. Based on this trial, pyroxsulam at three different rates provided better control when applied in the fall; however, the fall application only resulted in 60-80% control. A follow-up study was conducted on the ALS resistant Italian ryegrass that was reported in 2006. Seed from the ALS resistant ryegrass was evaluated for resistance to Osprey®. Based on the research conducted by Drew Ellis and Tom Mueller, the bio-type was highly resistant to Osprey, despite the fact that Osprey had never been applied in the field. Oregon State University-Corvallis Given increasing winter wheat acreage in the Willamette Valley (at the expense of mostly perennial ryegrass acreage) , several on-farm demonstration trials that showcase best sequential Italian ryegrass control in herbicide resistant and non-resistant populations have been completed. Long-term grass seed growers have selected for very little resistance in Italian ryegrass and are using older standards such as diuron followed by diclofop effectively. In other areas with multiple resistant Italian ryegrass populations flufenacet + metribuzin (Axiom) or flufenacet (Define) applications followed by pinoxaden or mesosulfuron can sometimes be ineffective (60-80 % control). Current recommendation for these Italian ryegrass populations is: delayed wheat planting with multiple tillage or glyphosate burndowns, EPOST Axiom or Define followed by POST pinoxaden or mesosulfuron depending on grass spectrum present or do not rotate to winter wheat. Becoming over reliant on Group 15 flufenacet. Evaluation of KIH-485 (Kumiai) for winter annual grass control in winter wheat. Lower injury potential than Axiom treatments in 2007. Evaluation of built in surfactant formulation of pinoxaden in spring wheat. Evaluation of pinoxaden and mesosulfuron compatibility with bromoxynil + pyrasulfotole in spring wheat. Longer-term cropping system studies initiated in Fall 2006 where the goal is to quantify evolution of resistance in Italian ryegrass to Group 1 and Group 2 herbicides. Combinations of two and three year crop rotations specific to the Willamette Valley-winter wheat, spring wheat, clover (seed crop), and canola. Confirmed glyphosate resistance in Italian ryegrass related to glyphosate overuse in filbert orchards. Three other sites suspected. Working on the mechanism of resistance. It is unknown as to how this may or may not impact small grain and grass seed cropping systems. Utah State University New herbicides were evaluated in winter wheat for broadleaf weed and wild oat control. Wild oat herbicides were evaluated alone and in tank mixtures with herbicides having broadleaf activity. Combinations of graminicides with herbicides for broadleaf weed control can antagonize wild oat control. Specific herbicide combinations can be selected to avoid antagonism. A bulletin on best management practices for jointed goatgrass control was completed in cooperation with other States. University of Wyoming Dr. Steve Miller is now on an administrative appointment, and Dr. Andrew Kniss began as agronomic weed scientist in August. Two studies were initiated in the fall looking at downy brome control with split applications (fall/spring) of several herbicides. A manuscript summarizing 6 years of research on jointed goatgrass management in imazamox-resistant wheat was recently submitted to Crop Science. This research was conducted cooperatively with Dr. Drew Lyon at the University of Nebraska.

Quinn, M., D. Morishita, J. Evans, R. Whitesides, and T. White. 2007. Jointed Goatgrass Best Management Practices (BMP) Intermountain Region. Washington State University Extension Bulletin, EB2003. Gaines, T., P.F. Byrne, P. Westra, S.J. Nissen, W.B. Henry, D.L. Shaner, and P.L. Chapman. 2007. An empirically derived model of field-scale gene flow in winter wheat. Crop Sci. 47:2308-2316. Gaines, T., C. Preston, W. Brien Henry, P. Byrne, and P. Westra. 2007. Adventitious presence of herbicide resistant wheat in certified and farm-saved seed lots. Crop Sci. 47:479-454. Gaines, T., W.B. Henry, P.F. Byrne, P. Westra, S.J. Nissen, and D.L. Shaner. 2008. Jointed goatgrass (Aegilops cylindrica) by imidazolinone-resistant wheat hybridization under field conditions. Weed Sci. 56:32-36 Lyon, D. J., R. N. Klein. 2007. Controlling jointed goatgrass. NebGuide G1252, University of Nebraska Lyon, D. J., and R. N. Klein. 2007. Rye control in winter wheat. NebGuide G1483, University of Nebraska. Herbicide-Resistant Weeds and Their Management. PNW 437. Carol Mallory-Smith, Oregon State University; Andy Hulting, Oregon State University; Donn Thill, University of Idaho; Don Morishita, University of Idaho; Jen Krenz, Oregon State University Quinn, M., D. Morishita, J. Evans, R. Whitesides, and T. White. 2007. Jointed Goatgrass Best Management Practices (BMP) Intermountain Region. Washington State University Extension Bulletin, EB2003.