Research on Jointed Goatgrass In Washington

Dr. Frank Young, a Weed Scientist with the USDA-ARS in Pullman, recently completed a project evaluating the possibility of spring germinating jointed goatgrass producing viable spikelets in spring planted wheat.  This project was the basis for a former master of science student, Darrin Walenta, and was completed in June 2001.  This study is based on the hypothesis that planting spring wheat and adjusting the time of planting will prevent the production of viable jointed goatgrass spikelets.  They concluded that delaying spring wheat planting can reduce jointed goatgrass seed production.  However, the risks of reduced yield needs to be weighed against this practice.  Young suggests using this information as part of an integrated management program.

Young is also involved in a long-term integrated management research project on jointed goatgrass. This study was completed in December 2001.  Young has showed the effects a competitive wheat variety has on jointed goatgrass .  “Edwin,” a club-type soft white winter wheat with excellent seedling vigor and a tall mature plant height was compared in plots with a standard soft white variety “Cashup.”  The Edwin cultivar appeared to be out-competing jointed goatgrass in plots infested with the weed.  At heading, Edwin heads were above the jointed goatgrass spikes, while the Cashup heads were the same height as the jointed goatgrass.  Jointed goatgrass was competing much more noticeably with Cashup than with Edwin.  Yield data was collected on these research plots during harvest in July and early August. 

“Combining a competitive wheat cultivar like ‘Edwin’ with integrated management practices such as deep-banding fertilizer, increasing seeding rates, planting high-quality (large size) certified seed, and rotating with spring crops makes a difference in jointed goatgrass control,” said Young.

Dr. Joe Yenish, Extension Weed Scientist at Washington State University in Pullmans, and Young are researching the best crop rotations for jointed goatgrass control using herbicide resistant wheat.  Clearfield® Production Systems for wheat from BASF will be available to northwest producers in two to three years.  The system combines locally adapted varieties of wheat possessing the Clearfield gene, with the herbicide Beyond®, also from BASF.  Clearfield wheat varieties are non-GMO, and bred using traditional plant breeding techniques.  Young and Yenish are researching crop rotation strategies in two production zones that will prevent the development and spread of herbicide-resistant weeds when Clearfield wheat is used to manage jointed.  Jointed goatgrass control using Beyond in Clearfield wheat often exceeds 98% in university trials.  The system also provides good control of cereal rye (with proper application timing), downy brome, and Italian rye.

This experiment is being conducted in a low rainfall (9-11 inch) zone and a high  rainfall (18-22 inch) zone.  The low-rainfall site is located on a farm near Pasco, Washington in a winter wheat-fallow rotation.  The high-rainfall site is in a winter wheat-spring cereal-spring legume rotation on a farm near Pullman, Washington.  This six-year study began in August of 2000 and will conclude in August 2005.

To find out more about the research conducted by Dr. Joe Yenish please contact him at yenish@wsu.edu or contact Doug Schmale, JGG Extension Coordinator.