A Cooperative Project
Fusarium blight, generally known as "scab", has emerged in recent years as an industry-threatening disease for all classes of wheat and barley in the United States. This proposal describes a comprehensive, collaborative project that synergistically harnesses and directs the research capacities of ten Land Grant Universities in the north-central region (Michigan, Minnesota, Indiana, North Dakota, South Dakota, Kansas, Nebraska, Illinois, Missouri, and Ohio). New, collaborative and multi-state activities designed to directly benefit all participants are proposed. Those activities will be complemented by strategic investments throughout the region to amplify and strengthen ongoing efforts aimed at understanding and combating this threat to America's agriculture, economy, and food safety.
I. Problem Statement
Scab is a disease of wheat and barley caused by Fusarium graminearum and related fungi. The effects of scab are most obviously manifested as reduced farm yield, lowered test weights, and reduced grain quality. Economic losses of this type were extraordinary in recent years. Across North Dakota, Minnesota, and South Dakota, yield and grain quality losses approached one billion dollars in 1993 and ranged from 200-400 million dollars across the region in subsequent years. Losses were in excess of 300 million dollars in Ohio, Michigan, Indiana, and Illinois in 1995 and 1996. Those facts are themselves alarming, but the problem is amplified to the level of a strategic threat because scab infected grain is usually contaminated with "vomitoxin" (deoxynivalenol) , a toxic metabolite produced when the fungal pathogen invades the developing kernel. Vomitoxin-contaminated wheat and barley has recently been greatly devalued by the U.S. marketing system. Because of a near zero tolerance policy, grain buyers refused to purchase any soft white wheat from Michigan in 1996 or malting barley from North Dakota. Several important international markets are poised to impose restrictions on vomitoxin levels that could result in continuing serious losses for U.S. producers.
Amelioration of scab as a threat to the producers and consumers of wheat and barley has proved to be one of the more intractable problems encountered in the era of modern agricultural science. Adequate genetic or chemical solutions have proven elusive. However, significant progress is evident in both those arenas. Unchecked, scab represents a profound threat to the economic and food safety environment of the United States. In Ohio, Indiana, Michigan, Illinois, Missouri, eastern Nebraska, as well as other soft wheat producing areas, scab could conceivably eliminate wheat as a viable component of cropping systems. This would have immediate, short-term implications for the well-developed wheat-based milling and food processing industries in those regions. In the long run, the reduction in landscape diversity and increases in soil erosion associated with the demise of wheat will in turn have severe negative consequences on the sustainability of our food production capacity. In the hard wheat production regions of the mid-west U.S., where wheat dominates the landscape, scab threatens the very fabric of America's rural economy. Barley production has already been either threatened or eliminated in areas of the upper mid-west where brewers have imposed near zero tolerance limits for vomitoxin in grain.
There is a strong consensus among the institutions collaborating in this proposal that the complexity and seriousness of this problem necessitates a concerted, regional effort. Action is urgently needed. Our food safety-conscious society and associated industries have shown a pronounced propensity to reject foodstuffs that carry connotations of health risks, real or perceived. The research and communication agendas proposed here are the result of a recent meeting of scientists from the states represented by this proposal.
II. Research Needs
Food Safety and Post-Harvest Management of Grain: Efficient and accurate monitoring of grain for vomitoxin contamination requires resolution of new sampling and testing protocols to prevent food safety problems. Commercially viable technologies for the safe and economically maximized handling of vomitoxin contaminated grain require development and dissemination. These may be based on separation, dilution, or detoxification approaches.
Plant Breeding. Conventional and Molecular Approaches to Variety Development and Germplasm Enhancement: The ideal solution to all facets of this problem is the development of wheat and barley varieties that are genetically configured to preclude scab development. Creation of an integrated network of scientists working to identify and evaluate all possible sources of resistance is a critical need. A few genes that impart partial resistance have been identified, but it is very likely that more exist. World germplasm collections, including the World Small Grains Collections maintained by the United States Department of Agriculture in Aberdeen, ID, have not been systematically evaluated for scab resistance. Effective, large-scale screening techniques are also needed to facilitate the incorporation of identified resistance genes into adapted wheat lines. Screening breeding materials ensures that the most susceptible varieties of those currently grown are eliminated from production. Ironically, the lack of uniformity of natural infections forces scientists to employ artificial inoculation techniques. Resolution and distribution of expert knowledge on this aspect of germplasm screening is critical. Employment of molecular techniques to accelerate plant breeding, provide basic information on the host-pathogen interactions, and as a possible source of novel, engineered resistance genes is a prime candidate for fruitful investment.
Epidemiology and Crop Management: The causal organism of wheat and barley scab has a diverse array of plant species on which it can thrive, including corn. Consequently, there is a wide range of sources of the pathogen each year. The occurrence of scab in wheat and barley is probably affected by the management strategies employed throughout a farm or region. However, a full understanding of the epidemiology of scab is yet to be resolved. What is the primary source of inoculum for the annual epidemics in wheat and barley? Are there management strategies that can lessen the risk of scab occurrence? Are there unidentified chemical control strategies? What combination of physical and biological conditions lead to scab epidemics? Can that information be used to predict scab epidemics?
Communication Networks: The scab problem is multi-disciplinary from a scientific perspective, and multi-sectored from an agriculture industry perspective. Proactive efforts aimed at concentration, integration, and dissemination of research, extension, and outreach-oriented information will return large benefits to the overall system.
III. Proposed Approaches and Research Emphases
- Core multi-state research and outreach activities:
- Food Safety and Post-Harvest Management Research Network. Appropriate management of scab infected grain requires reproducible and properly administered vomitoxin testing systems. Milling and food processing techniques that render vomitoxin-contaminated grain safe will be explored. The toxicological properties of vomitoxin will be investigated.
- Regional Advanced Breeding Material Evaluation Nursery System. All states will cooperate as evaluation sites. Two states will provide coordination of seed distribution and data summarization activities. Standardization of data collection and summarization techniques will maximize impact. Each state will benefit from collection of more evaluation data than achievable by a single breeding program operating alone.
- Germplasm Introduction and Evaluation System. There will be two coordinating centers, one in the spring wheat region, and one in the winter wheat region. This system will ensure that plant breeders are afforded access to all possible sources of favorable genes. There is no such system in place for scab or any other breeding objective for wheat in the U.S.
- Fungicide Application Technology Research Network. Development and deployment of alternative spray systems may boost the effectiveness of available fungicides. Alternative fungicide formulations may also provide effective control. Effective chemical control strategies, if developed, would provide relief for producers until new resistant wheat and barley varieties are available.
- Research and Outreach Information Network. Sponsorship and enhancement of the pre-existing annual Scab Forum and NCR-184 committee activities coupled with full exploitation of the "information highway" will maximize information exchange among scientists, thereby preventing unnecessary duplication of efforts. Integrated access via Internet technologies to extension and outreach information will not only economize efforts in that area but also ensure uniformity of the "message."
- Activities and research emphases to be implemented within each state.
- Strengthening and expansion of ongoing plant breeding efforts. Plant breeding programs targeting scab resistance are ongoing in all collaborating states. However, these efforts are hampered by an inadequacy of funds. Actual investments of funds requested here will depend on each state's strengths and needs. All information on techniques, including artificial inoculation and molecular approaches, will be shared via the information network described above.
- Expansion and integration of scab epidemiology and crop management research. Knowledge of the exact physical and biological conditions required for epidemics to occur will be examined and the findings applied to creation of forecasting systems. The actual mechanisms of infection and the sources of inoculum will be identified. Knowledge of the impact of same-field and regional farm management practices will be expanded.
The management and control of scab is a research area that will require sustained investment for an extended period of time. Rapid technological and informational developments are fully expected. The top-level management entity for the project will be a committee comprised of the Director's of the Agricultural Experiment Stations from each of the cooperating states. The initial annual budget request of $5,125,000 is detailed in Table 1. Funding of this magnitude is needed annually for a five year period.
IV. Benefits and Justification.
The health of our country's agricultural and therefore national economy continues to rely heavily on only a handful of crop species. Two of the critical crops for the United States are wheat and barley. Scab represents a serious, strategic threat to the wheat and barley industries in much of the United States. This proposal outlines a unique, large-scale cooperative effort developed at the scientific grass-roots level by plant pathologists, breeders, food scientists, and agronomists. It seeks to provide local flexibility within a firm framework of cooperatively identified and executed activities. Scab falls in the unique category of scientific challenges where neither existing public funding mechanisms, nor private investments are adequate to counter the threats posed. Current investments aimed at the scab problem at the Universities represented here total more than several million dollars per year. The regional integration and synergism that will stem from successful implementation of this project will amplify dramatically the impact of that ongoing investment.
Table 1. Annual budget.
|Food Safety and Post-Harvest Management Research Network||$1,000,000|
|Strengthening and Expansion of Ongoing Plant Breeding Efforts: Conventional and Molecular Approaches to Variety Development and Germplasm Enhancement||$2,500,000|
|Regional Advanced Breeding Material Evaluation Nursery System||$112,500|
|Fungicide Application Technology Research Network||$375,000|
|Germplasm Introduction and Evaluation System||$200,000|
|Expansion and Integration of Scab Epidemiology and Crop Management Research||$800,000|
|Project Coordination and Research and Outreach Information Network||$137,500|