|Seefeldt, Steven - NEW ZEALAND AGRICULTURE|
|Yenish, Joseph - WASHINGTON STATE UNIV.|
|Thill, Donn - UNIVERSITY OF IDAHO|
|Ball, Dan - OREGON STATE UNIVERSITY|
Submitted to: Jointed Goatgrass Symposium
Publication Type: Proceedings
Publication Acceptance Date: January 31, 1999
Publication Date: N/A
Interpretive Summary: Jointed goatgrass continues to plague winter wheat growers in the western United States by reducing crop yield, quality, and profitability. Jointed goatgrass is adapted to winter wheat production areas and cannot be selectively controlled in winter wheat. The only method currently available to reduce harmful effects of jointed goatgrass in winter wheat, other than crop rotation, is to utilize an integrated program of crop planting strategies. In a three-state, five-year study, winter wheat is planted using growers' standard practices compared to integrated planting practices. Integrated practices include starter fertilizer and N fertilizer at the time of planting, increased seeding rate and seed size, and planting a competitive wheat cultivar. During the 1997-98 growing season, integrated winter wheat increased yield an average of 25% compared to the standard winter wheat practices at the three locations in WA, OR, and ID. In Oregon, dockage from jointed goatgrass seed in wheat decreased from 2.4% in the standard practice to 0.4% in the integrated system. Reducing dockage 2% increased farm profitability 25 cents per bushel. In the past two years, winter wheat fertilized with starter fertilizer and N at the time of planting had better emergence and stand establishment than wheat without starter fertilizer and N applied four months earlier.
Technical Abstract: In the Pacific Northwest, jointed goatgrass was first recognized as a major deterrent to reduced or no-till winter wheat cropping systems in the 1970s. Since then, many individual chemical, cultural, mechanical, and preventive methods of jointed goatgrass control have been examined. In the Pacific Northwest, loss of soil is very high because of water and wind erosion. In nthis study, we focused on long-term, inter/mutli-disciplinary systems research for the management of specific weed species in cropping systems. Mechanical tillage is not a viable option for jointed goatgrass control. In the fall of 1996, a total integrated system for the management of jointed goatgrass was initiated in the field in the traditional winter wheat/fallow region of WA, OR, and ID. The multi-state project is designed to utilize the information generated from the many single component jointed goatgrass studies conducted in the PNW. Project treatments include one- time burning, crop rotation, and integrated practices for planting winter wheat. Data to be collected include a) weed seed viability and density in the soil; b) jointed goatgrass plant density each year in each system; c) crop yield and dockage; and, d) economics and risk assessment.