Agronomics and Economics of No-till Facultative Wheat Produced in the Dryland Pacific Northwest.
Laylah Scarnecchia, Frank Young, Joseph Yenish, Richard Alldredge, and Douglas Young. Washington State Univ, P.O. Box 646420, Pullman, WA 99164-6420
Since the 1900’s, winter wheat rotated with dust-mulch summer fallow (WW/SF) has been the dominant production practice in the low-precipitation zone (<305 mm) of the Pacific Northwest (PNW). Over time, WW/SF has developed several problems including severe wind erosion, increased pest problems and costs of production, and reduced crop yields. Producers need crop and system alternatives to replace or incorporate into the traditional WW/SF system. One proposed alternative is production of no-till facultative wheat rotated with chemical fallow (FW/ChF). Facultative wheats are characterized by strong photosensitivity and partial sensitivity to vernalization. In general facultative wheats have less cold tolerance, a shorter but distinct period required for vernalization, and start growing and flower earlier compared to true winter wheats. The general objective of this research was to determine if FW/ChF would be a viable alternative for growers in the PNW. In 2003, rotations of FW/ChF and no-till facultative wheat/spring wheat (FW/SW) were incorporated into a larger conservation tillage cropping systems study initiated in 1995. Results will focus on the agronomics, economics, and weed species dynamics of FW/ChF, FW/SW, and WW/SF. Research component results will be summarized, with a major focus on agronomics and economics of FW/ChF compared to FW/SW and WW/SF. Facultative wheat planted in late-fall, with early spring emergence and potential to yield as high as winter wheat, may be a viable option for growers in this region. Over the 4-year study period FW/ChF yielded 538 kg/ha higher in 2003 and 403 to 1747 kg/ha lower in 2004-2006, than WW/SF. Facultative wheat/chemical fallow yielded 1277 and 1411 kg/ha higher than SW/FW in 2003 and 2005 respectively, and 1478 kg/ha higher than FW/SW in 2005. In 2004 and 2005 FW/ChF, SW/FW, and FW/SW yielded similarly. Both FW/SW and SW/FW yielded between 403 and 2621 kg/ha lower than WW/SF.