Developing Priorities for Research
Over the past three years, nearly $20 million has been allocated to fund 125 completed and continuing research projects to address Pierce’s disease (PD). Support for the projects has come from the California Department of Food and Agriculture (CDFA), the PD–GWSS [glassy-winged sharpshooter] Board, the University of California Pierce’s Disease Research Grants Program, the United States Department of Agriculture–Animal and Plant Health Inspection Service (USDA–APHIS), the American Vineyard Foundation, the California Competitive Grant Program for Research in Viticulture and Enology, the California Citrus Nursery Advisory Board, the Almond Board of California, and the California Department of Transportation (Gleeson et al., 2004). The hope is that the research will produce tools and tactics for management of Xylella fastidiosa (Xf) and its insect vectors in the short term and to PD prevention and cure the long term (CFDA, 2004).
The research effort has yielded some progress. Successful management efforts include chemical control of GWSS populations; removal of PD-infected grapevines; and, to a lesser degree, the identification, manipulation, or removal of host plants for GWSS from the individual landscape. The research that focuses on prevention and cure has led to improved understanding of the genetics and biology of susceptible and resistant interactions between grapes (Vitus vinifera L.) and Xf.
Despite those accomplishments, however, there are numerous gaps in meeting the short- and long-term objectives. For example, it is not known whether management efforts are effective for maintaining the disease below
economic thresholds, nor are there complete data on the effects of area wide management programs (Gleeson et al., 2004). The gaps in knowledge about prevention and cure are substantial. Given the short period of intense study, however, and the complexity of the challenges presented by PD, the insect vectors, the host plants, and the California agricultural landscape, those gaps are not unexpected.
Although most of projects funded over the past 3 years are only now beginning to yield results, current federal and state fiscal challenges are likely to reduce the amount of funding available for agricultural research, outreach, and management programs. That fiscal reality and the economic consequences of PD provide the context for the Committee on California Agricultural Research Priorities: Pierce’s disease deliberations: the need to focus priorities for research on the biology and management of the PD–GWSS problem.
The California Department of Food and Agriculture has divided the current PD–GWSS program into nine areas of basic research (Gleeson et al., 2004):
crop biology and ecology ($1.34 million)
vector basic biology ($692,000)
insect–plant interactions and vector population ecology ($1.09 million)
genetics of Xf ($930,000)
Xf––host plant–insect interactions ($3.2 million)
Xf disease epidemiology ($1.26 million)
vector monitoring and action thresholds ($1.38 million)
Xf monitoring and action thresholds ($1.56 million)
The program also supports development of applied strategies for managing PD–GWSS:
biological control of Xf and vector ($3.0 million)
chemical control of Xf and vector ($3.68 million)
cultural, physical, and behavioral control ($435,000)
resistance to Xf diseases ($1.07 million)
Basic research accounts for just over half of the funding, with projects that examine interactions between the host, the insect vector, and the pathogen receiving the largest share. Most of the funding for applied research has been spent on studying chemical controls of the vector. Economics studies are noticeably under funded.
The collective of topics encompassed by the research program addresses the breadth of issues important in the exploration of the PD–GWSS problem. The program appears to be positioned to identify mechanisms for interfering with one or more of the interactions between the host, the vector, and the pathogen. Successful interference with any one of them could break the chain that culminates in plants succumbing to PD. By identifying particular mechanisms, researchers eventually can provide growers with tools and strategies to minimize risks or consequences of the disease in agricultural production. The concept of host–vector, vector–pathogen, and host–pathogen provided the committee with a logical way to group the research efforts. In subsequent Chapters 3, 4, and 5 of this report, the committee uses those groupings as the focus for evaluating the individual elements of the current program.
Although the PD–GWSS research agenda is broad, to most effectively address PD–GWSS, the program also should attempt to increase the odds of identifying interference mechanisms and consequent management strategies. It is important to recognize the varying pace at which information will flow from different projects and to assess the relative value and quality of information in leveraging progress from the whole of the program. Some subject areas or projects can be given more emphasis than others as the overall research progresses over time. It is also important to fund only those projects that meet the highest standards for scientific rigor. That strategic approach rests on the ability of the program to achieve significant coordination in the solicitation and selection of projects and to maintain the flexibility to shift priorities as research results provide new information.
For several reasons, including the relatively short life of the program, the research agenda seems to be the result of a loosely coordinated process. The committee had difficulty understanding the basis for or the process of priority setting. Communication among the various entities (see Figure 1-2) occurs through the overlapping of memberships of the various boards and panels. CDFA receives advice from the PD/GWSS Board about which projects to fund. That board relies on its research-screening subcommittee to solicit and evaluate new projects and to evaluate the projects already under way. The PD/GWSS Board seeks reviews and evaluates projects that are overseen by the CDFA, and there is board representation that overlaps with other entities that distribute research funds, such as the University of California Pierce’s Disease Research Grants Program and USDA–APHIS, or that are involved in PD–GWSS research, such as USDA–ARS. In addition, the Advisory Task Force on Pierce’s Disease is expected to assist CDFA in identifying viable funding sources and in planning long-term research agendas. A science advisory panel advises the Advisory Task Force on technical matters. Although coordination is attempted through the overlap of representation, interviews with experts and stakeholders familiar with the Pierces’ Disease Control Program reveal a lack of coordination among the various funding entities and the advisory groups. The result is a lack of clear communication between those bodies and CDFA, among the bodies themselves, and between the bodies and the scientists who receive research support.
The disparate priorities of stakeholders also affect strategic coordination of the program. For example, industry is searching for a solution to the commodity problem while much of the research community is still attempting to understand the basic biology and epidemiology of PD–GWSS. Although there are good reasons to pursue research on management options and on basic questions of biology, disjointed selection of projects could hinder opportunities to create synergies or hamper a logical progression of projects. The result could be a series of in individual, incremental successes that are inefficient from the perspective of the goals and the progress of the research enterprise as whole, particularly in the face of limited resources.
The greatest concern of the committee is that the scientific merit of the proposals is not receiving consistent scrutiny and attention. A strategic research program tries to ensure that consistently high scientific standards are applied in the review of proposals and in the evaluation of the research agenda so that the best work (and the best mix of projects) can move forward. Research proposals now are presented for consideration through multiple channels and follow different pathways to approval; there are even different methods of allocating funds once projects are approved. Depending on the pathway, proposals can receive different amounts of scrutiny and evaluation, and many proposals are reviewed more than once by the same peoples in the context of different committees associated with the program. Although that might eliminate the possibility that the same proposal would receive funding independently via different pathways, the redundancy still is inefficient and time-consuming.
So little information is available about the PD system that it makes sense to support a variety of projects, but ensuring the selection of the strongest scientific projects—those that are well conceived and that will generate reliable, useful data—is the best way to guarantee progress and the ability to intelligently focus resources on the most promising directions.
Recommendation 2.1. To ensure scientific rigor in, and enhance coordination of the PD–GWSS research program, participating research sponsors should consolidate the processes for proposal solicitation and review.
A consolidation would facilitate the identification of strategically critical projects and programmatic gaps (critical areas that are not receiving funding), avoid redundancy in the selection of research projects, eliminate overlapping processes, reduce costs, and distinguish projects for which teams or consortia should be established from those grants appropriate for one or two principal investigators. Consolidation adds uniformity and balance in determining the scientific merit of proposals. Box 2-1 explores some of the issues related to establishing high standards for proposal selection.
The National Institutes of Health (NIH), the National Science Foundation (NSF), and the USDA’s National Research Initiative (USDA–NRI) are recognized for the rigorous processes they follow for evaluation of extramural projects and proposals. Their attention to scientific merit is considered to offer the best peer evaluation (NRC, 2003). The committee suggests the methods those groups follow as models for the PD–GWSS proposal review process.
Those agencies issue national (and sometimes international) requests for proposals, they set clear guidelines (program scope, grant length, funding, and evaluation criteria) that also clearly describe the funders’ expectations for the progress required to receive continued support. Solicitations typically define and request individual and consortium (multi–investigator) types of projects based on the sponsors’ visions of short-, medium-, and long-term program priorities.
To ensure the highest scientific standards, the grant programs require that those who oversee solicitation and review of proposals are distinguished scientists, free of conflicts of interest. That is, those persons are not themselves receiving support from the relevant grant program while they are involved in the review, or at a minimum, that they have no proposals under consideration in the current year. Those persons also must have experience in handling proposals, have the time to spend on the substantial work involved in proposal review, and be able to communicate effectively with principal investigators and agency sponsors. The people who oversee the review process come from the major areas of expertise relevant to the research in question. In the case of Pierce’s disease, the disciplines would include entomology, ecology, economics, genetics, plant biology, plant pathology, microbiology, and molecular biology. Typically, membership in the oversight group rotates, using fixed term lengths to ensure stability and continuity and allow needed expertise and fresh perspectives to be incorporated.
Oversight groups for NIH, NSF, and USDA–NRI always recruit additional external peer reviewers, generally national and international experts, to help review the proposals. Based on the reviewers’ assessments, individual proposals typically are ranked for scientific quality, cost effectiveness, and the degree to which they meet program criteria. The research sponsors (for example, different institutes within NIH) then decide which of those recommended will receive funding.
A similar process is used to determine eligibility for continued funding. Progress can be assessed through evidence of achievement of benchmarks established by a principal investigator at the beginning of the project, submission of annual reports, or publication of research reports in peer-reviewed journals—which constitutes an additional level of scrutiny. Presentations at scientific meetings can offer another means of assessing progress. The American Vineyard Foundation calculates a measure of efficiency for researchers in terms of how many results a researcher produces for each unit of resources invested. That kind of measure, however, might not consider the complexity of scientific endeavor, especially in the study of fundamental mechanisms that, once unlocked, lead to major breakthroughs in application.
During the course of its work the committee established a framework that could assist CDFA in the development of its research agenda. Chapters 3, 4, and 5 use the framework to examine the current research program. If the PD program were to consolidate its processes, the proposed framework could be used as an evaluation and priority-setting tool. The framework flows from the principal that the problem of PD can and must be addressed by a range of approaches that are scientifically rigorous (regardless of whether the research is basic or applied), ecologically sound, and economically feasible and that provide sustainable solutions. The most effective response to PD is likely to emerge at the nexus of information contributed by different approaches. The framework consists of two independent evaluation criteria—feasibility and sustainability—and a system for grouping current and prospective research projects into categories that reflect differences in risk, cost, and relative effectiveness.
The first evaluation criterion assesses the ability of projects to produce applications that will help solve the PD–GWSS problem.
Feasibility: Considering technical barriers and practical limits (including cost), what is the likelihood that the research will result in tools for effective management of PD–GWSS?
Time: What period is required for the research effort to deliver an effective strategy, approach, or tool?
Effectiveness: What is the likelihood that the research product will deliver a strategy that will improve the PD–GWSS situation? Because the degree to which a given strategy or product will change the situation will vary, it must be determined whether the degree of change is better or worse than that achieved by other management measures and whether the strategy or product is sufficiently effective to warrant funding.
Cost: What will it cost to accomplish the research objectives?
Sustainability: The second criterion addresses the important idea of long-term application of a strategy or product. Is the approach or product biologically adaptable and affordable? Will it remain useful for a long period? Efforts to manage disease or pest outbreaks in agriculture often promote research that results in effective short-term solutions, but because diseases and pests are dynamic and evolving, those control measures often are not sustainable.
With information on the first factors for any given project, the research can be classified into one of four categories:
Category 1: The research option holds reasonable promise of generating successful tools for the management of PD–GWSS, either in the short term or in the long term.
Category 2: The research approach looks promising, but either because of insufficient data or because of inconclusive results, it is difficult to predict whether it will lead to successful applications for management.
Category 3: The research effort can produce data and results that are promising for successful management of PD–GWSS, but because of its complexity and the technology required, it would be prohibitively expensive for any one funding source to manage.
Category 4: The research approach does not show promise even in the long term, for PD–GWSS management.
The assignment of projects to those categories provides a useful way to examine options for the program as a whole. In considering how projects might be selected from within any category, the committee returned to the criterion of sustainability, concluding that, because many short- and medium-term control options are unlikely to be sustainable, a mixture of projects should be considered.
It is important to recognize that several factors other than purely scientific considerations will affect decisions to pursue or implement particular management strategies. For example, the cultivation and maintenance of unique lineages of grapes that result in the production of distinctive varieties of wine, such as chardonnay or cabernet sauvignon, adds value to grape production, but it severely limits the opportunities for crop improvement strategies that focus on breeding for disease or insect resistance by the methods conventionally used in many other crops. Although the process of categorizing research options focused on the potential effectiveness, time, and cost of a particular approach, the report mentions those factors when applicable. In some cases they are directly related to the issue of sustainability.
Recommendation 2.2. Research priorities should be developed according to their ability to meet two criteria—the predicted ability of the approach to contribute to PD–GWSS management and its sustainability. The committee recommends a balance among short-, medium- and long-term research projects to ensure the development of sustainable management approaches.
Economics: An Overarching Research Need
At least some information is available about the scientific aspects of different research and management approaches, but the same cannot be said of economic data, as illustrated by the lack of information about the economic consequences of PD described in Chapter 1. But the cost of PD that drives research, and economic considerations provide the context for setting research priorities. Because it is not economically feasible to pursue all possible projects simultaneously, priorities for the advancement of PD management strategies must be examined relative to the costs incurred in their implementation. The objectives and costs are different for different stakeholders, including growers and the wine and table grape industries and for the general public. Economic
costs (and benefits) are shaped by many factors, including environmental concerns, issues of sustainability, and the effects that PD can have on crops. Economic analyses should be implemented for short-, medium-, and long-term PD management strategies.
Chapter 3 discusses that issue as it obtains biological control and includes a more specific economic analysis of pesticide regimens. The attention given to the economics of pesticide-based control of GWSS should not be interpreted as suggesting that other management strategies should receive less attention from economists. Pesticide or chemical treatment is recommended for economic analysis because it is relatively easy to quantify and it lends itself to economic analysis. In fact, it is possible that other measures developed in the short run might be more useful for controlling PD, and those measures should also be evaluated from an economic perspective. For example, the use of barrier crops or nets along riparian area and vineyard interfaces are short-run measures that warrant economic analysis.
Thus far, however, economic analysis of PD has been confined to the studies by Siebert (2001) and Brown et al. (2002). No economic analysis of research-based management outcomes has been done. An economic analysis is needed to help determine which outcomes will be most satisfactory to growers.
Recommendation 2.3. An economic analysis, including a study of environmental impacts, should be conducted for all potential management strategies and outcomes (Category 1).
Economic analysis of management outcomes should focus on developing estimates of the economic consequences, including the implications for financial risk that are associated with management alternatives. That process would include estimating the cost, effectiveness, and reliability of management alternatives to identify the most attractive from a grower's financial perspective.
Economic Research Needed on Sustainable PD Management
The GWSS was introduced to California through human activities, and the species spread from its original location as a result of human activities. Some who are familiar with GWSS in California do not regard it as a unique or new PD vector. Remarks to the committee by the director of the American Vineyard Foundation (Gleeson, personal communication) indicate concern that GWSS is just one vector of PD; others eventually will emerge. Thus, GWSS is only the current focus of a more troubling long-term problem with PD.
The need to manage invasive species, such as GWSS and others that could emerge as PD vectors, could become even more significant in the years ahead than in has been in the past, for three important reasons: First, the trend toward reduced in barriers to trade will increase the volume of goods traded regionally and internationally and provide a concomitant increase in the accidental transport of potential PD vectors across regional and international
boundaries. Second, the Internet is dramatically increasing the accessibility of biological commodities to buyers in all regions, and is thereby greatly adding to the difficulty faced by regulatory agencies in protecting regional and domestic environments. Third, there is a growing awareness of the biosecurity issues that attend domestic crop and livestock production (Wheelis et al., 2002). Because of potential multiplier in regional and statewide economic effects, high-value crops could be attractive targets in this regard.
The current concern about PD is the result of GWSS as introduced in California by human activities. In view of this, it is perhaps not surprising that changes in human behavior could be part of a more permanent solution to PD. Drawing parallels with public-health programming related to HIV. C.H. Perring and colleagues (2002) argue that, in general, the probability of both the establishment and the spread of invasive species depends on human behavior, and incentives and institutions are needed to help change behavior that is not in the public interest. They conclude that control of invasive species is a public good that cannot be provided by uncoordinated, individual efforts. Aside from current CDFA nursery regulatory, bulk grape, and bulk citrus programs, there could be an array of policy instruments and institutional structures that could reduce the probability of GWSS spread in California and avert the introduction and spread of other PD vector species. The relative cost of most policy alternatives is largely unknown, although efficiency studies are possible. Sharov and Liebhold (1998) focus on the general use of barrier crops to impede movement of invasive species. With specific reference to PD–GWSS, Brown and colleagues (2002) optimized barrier zone width in vineyards. More economic analyses along those lines are needed to promote efficiency gains in PD vector containment.
Private and commercial activities can disregard the risks imposed on the agricultural economy in California. Study of policy alternatives for internalizing those risks to lessen the probable consequences is lacking, as is the study of regional or multi/state institutions to deal efficiently with PD vector issues. Economic analysis is needed to inform cost-effective and equitable policy regulations, incentives, and institutions that will lessen the probability of PD vector introduction and movement. The current statewide inspection program reveals the crux of the problem. Significant costs are being borne by entities, such as nurseries, with little to gain. If effective and sustainable vector control is to occur, some mechanism for reward or compensation must be in place. The design of that mechanism must be based on analysis of costs and industry operations.
Recommendation 2.4. The long-term research agenda should include economic analyses of policy regulations, incentives, and institutions to limit introduction and movement of PD vectors (Category 2).
Although the introduction of GWSS as well as its spread and the costs that have followed for commercial agriculture must be dealt with in the present, it is also important to acknowledge that the future could hold additional PD
vectors. The experience with GWSS could provide information about economic policy regulations, incentives, and institutions that could discourage introduction and movement of future PD vectors. We recommend that effort be carried out over 15–25 years because its intent is not to focus on developing incentives for growers to adopt given practices related to GWSS; rather it is designed to address a more general issue, of which GWSS is a current symptom. The experience with GWSS could facilitate learning that can be applied to new problems as they emerge.
In the remaining chapters of the report, the committee uses its framework to evaluate and categorize current and prospective research strategies for PD–GWSS and, ultimately, as the basis of its research recommendations.