WERA097: DISEASES OF CEREALS
Statement of Issues and JustificationThe cereal grains, particularly wheat and barley, constitute major cash crops throughout the western region of the United States. The types of cereal grains produced are diverse, including soft white winter, soft white spring, club, hard red winter, hard red spring, and durum wheat classes; 2-row and 6-row winter and spring feed and malting barley types; hay, grain and/or forage oat types; and grain and/or forage triticale types. Areas of production for these diverse crops overlap throughout the western region, and production occurs in both high and low rainfall areas, with or without irrigation, and under a wide-range of other production inputs (level of fertilization and degree of weed, insect, and disease control inputs). Overall, western cereal production is geared for the bulk commodity and specialized niche domestic markets as well as for export. In these markets, profit margins are slim and to remain competitive, cereal producers desperately seek assistance to reduce operating costs and minimize disease losses.
To maintain profitability in a diverse and changing disease environment requires constant surveillance and rapid responses to emergent disease problems. Over the last five years, several important cereal diseases have emerged in the Western United States. The most notorious of these have been Fusarium head blight and stripe rust of wheat and barley. In 2004, Fusarium head blight (scab) spread from the corn-belt states and Northern Great Plains into Inter-mountain regions of the Western U.S. causing millions of dollars in lost production. While losses are not as pervasive as in the Great Plains, individual growers experience catastrophic losses that can only be addressed through adapting head blight control measures to local situations. This includes development of resistant cultivars suited to local production systems, the validation of previously developed disease models, and utilization of specific agronomic practices and fungicides to reduce infection and toxin accumulation. In this situation, professional connections established through WERA-97 helped provide technical support that enhanced research responses. In contrast to Fusarium head blight, new races of stripe and leaf rust annually migrate eastward from Pacific coastal areas and northward from the Gulf states into central and northwestern regions. With ever changing virulence profiles, maintaining effective varietal resistance to both stripe rust and leaf rust requires constant vigilance. When resistance breaks down, the consequences are dramatic as seen with the 2003 stripe rust epidemic which caused an estimated 89 million bushels in lost wheat production. By enhancing cross communication among USDA rust specialists, state plant pathologists and breeders, more coordinated and responsive breeding efforts are being conducted than would otherwise be possible.
In addition to emerging diseases, changes in production practices to more intense, no-till cereal production has lead to shifts in disease dynamics. Increases in severity and incidence of Cephalosporium stripe, Fusarium crown rot, common root rot, root lesion nematodes, eyespot, and wheat streak mosaic have been documented. These diseases are persistent, endemic threats that have increased in severity and incidence in the past decade. Maintaining WERA-97 is instrumental in addressing these issues on regional and national basis. Looking to the future, WERA-97 is providing a forum to address emerging threats. In particular, new races of stem rust found in North Africa are currently spreading across central Asia and can be expected to reach North America in the coming decade. In these environments of constantly changing disease dynamics, the relationships developed through WERA-97 between USDA scientists, university and local researchers are vital to maintaining a safe and secure U.S. cereal production system.
With states having limited resources to address the plethora of disease related losses, responses need to be efficiently obtained through coordinated efforts of state and regional programs. By providing a forum for communication and collaboration, WERA-97 enhances synergy amongst participating members, minimizes redundancy and ultimately provides a more responsive targeting of research and extension efforts to assist producers in reducing disease related losses. Current member states include California, Colorado, Idaho, Kansas, Minnesota, Montana, Nebraska, North Dakota, Oregon, South Dakota, Texas, Utah, and Washington. The Committee welcomes participation and input from states outside the region and is reaching out to currently non-participating western states to solicit their involvement. Joint meetings with NCERA-184 at Idaho Falls, Idaho, in 2007, the Western Wheat Workers and the NCERA-184 at Davis, California, in 2008, and with the Western Wheat Workers at Corvallis, Oregon, in 2009 are good examples of the Committee reaching out to a wider spectrum of researchers and disciplines related to plant pathology.
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