Duration: 10/01/2007 to 09/30/2012

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Onion (Allium cepa) is an economically important crop in the U.S., generating over 900 million dollars annually in farm receipts from 2000 to 2004. U.S. onion production area ranges from 65,000 to 70,000 hectares annually, with over 80 percent of the summer production (54,000 hectares) in the western states. On average, 53 million metric tons of onion bulbs are harvested annually from nearly 3 million hectares worldwide. A significant portion of the U.S. and world supply of onion seed is produced in the western U.S., primarily in the Pacific Northwest.

Projected economic impacts of Iris yellow spot virus and thrips in the U.S. could reach 60 million dollars (10 percent loss) to 90 million dollars (15 percent loss), in addition to environmental and economic costs due to additional pesticide sprays for thrips control (7.5 to 12.5 million dollars for 3 to 5 additional sprays on 48,500 hectares per year) on onion, and potentially on other allium crops. JUSTIFICATION: Iris yellow spot virus and its Thrips tabaci vector represent an immediate and serious threat to sustainable and productive onion production in the U.S., and the recent detection of this disease in numerous onion producing countries worldwide emphasizes the need to develop economically sound and effective IPM strategies.

The overall objectives of this project have been discussed in previous allium meetings by the 20 or more participants on this regional project, and are designed to promote the national network of onion and other allium researchers, extension personnel and industry reps.

Related, Current and Previous Work

In 2001, IYSV was observed in bulb onion crops in Colorado (Schwartz et al., 2002), Utah, and Idaho (J. Moyer, personal communication). IYSV has since been confirmed in all onion producing states in the western U.S., including California, Arizona, New Mexico, Nevada, Oregon, and Washington (Creamer et al., 2004; Crowe and Pappu, 2005; du Toit et al., 2004; J. Moyer, personal communication); as well as recently in Texas (Miller et al., 2006) and New York (C. Hoepting et al., 2007).

The 2003 Colorado IYSV epidemic is estimated to have cost growers $2.5 to $5.0 million in farm receipts alone (Schwartz and Gent, unpublished). During 2004, outbreaks of IYSV seriously reduced yields of bulb onions as well as onion seed crops in Washington and Oregon. Some seed fields had 7 to 20% infected plants, in which the flower stalks (scapes) that lodged could not be harvested. One seed field in Washington was completely abandoned because the male parent was decimated by IYSV and thrips within two months of planting, at an estimated loss to the grower of $100,000. If the rate of spread and damage from IYSV and thrips continues unchecked in the western U.S., projected economic impacts could reach $60 million (10% loss) to $90 million (15% loss in farmgate value), in addition to environmental and economic costs incurred from an increase in numbers of pesticide sprays despite their limited efficacy ($7.5 to $12.5 million dollars for 3 to 5 additional sprays on 48,500 hectares per year) (Schwartz, unpublished). IYSV is an immediate and serious threat to sustainable and productive onion production in the U.S. (Boyd, 2003), including (since 2004) the Vidalia onion industry in Georgia, and now bulb production in New York and Texas. The rapid and international spread of this disease emphasizes the need to develop economical and effective IPM strategies.

The reasons for the sudden development and dissemination of IYSV on onion bulb and seed crops in the western U.S. remain unclear. Seed transmission does not appear to be epidemiologically important in disease development (Mohan and Moyer, unpublished), although low levels of seed transmission (<0.0001%) have not been disproved. A new vector or strain of the onion thrips vector that more efficiently acquires or transmits the virus may have been introduced into the western U.S. Alternatively, a more virulent IYSV strain may have been introduced. Abad et al. (2003) reported that two genetically distinct populations of IYSV onion strains exist in the western U.S., based upon N gene sequence diversity. They also discovered a third subgroup of strains infecting chive that may constitute a new distinct tospovirus. The N gene diversity may reflect host or ecological niche specialization. Additionally, the nucleocapsid protein of a Brazilian onion strain of IYSV was 9.5% divergent from iris strains isolated from the Netherlands and the strains also differed in host range, further suggesting an ecological specialization (Pozzer et al., 1999). Perhaps just as importantly, there have been increased cases of the difficulty of controlling onion thrips due to changing environmental conditions (thrips are more problematic in hot, dry weather and such atmospheric conditions are becoming more common) and problems with insecticide resistance (see below).

The spatial distribution of IYSV-infected plants varies within and among onion fields depending on cultivar, plant population and location in the field (Gent et al., 2004). In Colorado, distinct disease gradients were observed in two fields with susceptible and moderately resistant cultivars. The significance and basis of disease gradients across fields are unknown, but do not appear related to prevailing wind direction or specific bordering crop (Gent et al., 2004). Correspondingly, distinct edge effects have been documented in onion bulb crops in Colorado, where the highest IYSV incidence was often found on the borders of fields and the lowest incidence near the field centers (Gent et al., 2004, unpublished results from existing study). Interestingly, plant population was negatively correlated with IYSV incidence in a field planted to a moderately resistant cultivar (explaining 56% of the observed variability in IYSV incidence), but not with two susceptible cultivars. Altering planting patterns and avoiding thin stands reduces tospovirus incidence in other cropping systems (Brown et al., 2001), but the effect of planting pattern on IYSV incidence remains unknown. Spatial disease patterns also appear to be associated with plant stress (Schwartz, Gent, and Mohan, unpublished). In studies during 2003 to 2006, we obtained and analyzed soil samples and remotely-sensed bare soil imagery from plots with known IYSV incidence. A significant relationship was detected between incidence of IYSV for a moderately resistant cultivar and soil color, as well as other edaphic properties such as salinity, pH and texture. Plant stress alleviation may be a central component of an integrated and sustainable IYSV management program. Further study should elucidate the relationship between plant stress, symptom expression and disease management. This research has being supported, in part, by a grant from the Western Region IPM Center for 2005-2006; see progress report.

Onion growers in the western U.S. currently rely almost exclusively on insecticides for thrips management. Problems with insecticide resistance in western populations of onion thrips have been anecdotally reported for over 15 years. Failure of organophosphates (e.g., methyl parathion and azinphosmethyl) to control thrips was widespread by the early 1990's; their use by growers has ceased for over a decade. The pyrethroids originally provided improved thrips suppression, but shortly afterwards resistance of thrips was observed to rapidly develop in onion fields treated with permethrin, cypermethrin, and lambda-cyhalothrin (Al-dosari, 1995). This response has more recently been demonstrated again in New York (Shelton et al., 2003 and 2006). Resistance development occurred within individual fields in a single season and cross-resistance among pyrethroids was demonstrated. Problems with resistance to pyrethroids have since increased. Poor control with the pyrethroid standard, Warrior (lambda-cyhalothrin), has been reported from all onion producing areas in Colorado since 2001 and growers have responded by increasing insecticide rates and shortening application intervals.

Given the unreliability of pyrethroids to control thrips, several other insecticides have received extensive testing and some have been considered for or received SLN registrations (e.g., formetanate hydrochloride, spinosad, abamectin). In general, these products and others seem to perform better against thrips in eastern US onion fields than in onions in the west. We speculate that there are two major reasons for these differences. First, there is a longer duration of thrips pressure in the western US, sometimes up to nearly two additional months, compared with the eastern U.S. Second, insecticide coverage in western onion fields is not likely as good as it is in the east. Growers in the west tend to spray onions by air using up to only 7 gallons per acre, while growers in the east use ground rigs and apply insecticides at 30 to 60 gallons per acre. A review of insect control studies on onion in Colorado from 1995-2006 has been compiled by Cranshaw (2006) and results from similar studies in New York have been reported by Nault and Hessney (2006, 2007).

In addition to the insecticides mentioned previously, there are only two others in the pipeline that have demonstrated excellent and consistent control of thrips. The first is spinetoram (Radiant SC), which is closely related to spinosad, and it is applied as a foliar spray. Dow AgroSciences anticipates submitting a Section 3 package to EPA for spinetoram on onion later in 2007 (J. Dripps, personal communication). The other product is fipronil, which is a phenylpyrazole. Although fipronil is not likely to receive registration for foliar use on onion use because of risk cup issues,it may receive registration as a seed treatment (new proposed name is Mundial). EPA has been reviewing fipronil as a seed treatment on onion since 2005. This use primarily has been developed to manage onion maggot (Nault et al. 2006); however, because fipronil has systemic activity, early season thrips suppression in the western US is possible for onion bulb producers and is likely for onion seed producers

Reliance on insecticides alone to control thrips in onions is not sustainable. Alternative thrips management strategies have been evaluated in Oregon with some success (Jensen et al., 2002). Biological-based insecticides, e.g., spinosad, azadirachtin (neem extract), provided poor thrips suppression alone, but when combined with straw mulch results have been promising. These results were repeated in Colorado during 2004 to 2006 (Schwartz et al., unpublished). Studies in New York have indicated that straw mulches can delay the arrival of onion thrips as well as provide some level of season long suppression (Shelton et al., unpublished). This suggests that the use of mulches, combined with insecticides with low impact on natural enemies of thrips, may be more successful and sustainable in onion production systems.

Cultural practices can also significantly influence thrips population dynamics (Schuch et al., 1998; Stavisky et al., 2002) and the incidence of tospoviruses (Stavisky et al., 2002). Modification of cultural practices is an environmentally-sound and often underutilized means of thrips and tospovirus management. For example, managing nitrogen fertilization has successfully reduced thrips populations on some crops (Brodbeck et al., 2001; Mollema and Coloe, 1996; Schuch et al., 1998), and may also be useful in tospovirus management (Stavisky et al., 2002). Additional studies have suggested that removal of culls in the field can reduce the populations of thrips, especially early in the season (Shelton et al., unpublished).

Another promising and sustainable means for long-term thrips management is development of cultivars with tolerance to thrips injury. Several evaluations of onion cultivar suitability as thrips hosts have been reported (Coudriet et al., 1979; Jones et al., 1934; Saxena 1977). These studies documented differences in thrips populations colonizing different cultivars, but the differences in thrips numbers on different cultivars have generally been more modest. Al-dosari (1995) expanded the idea of thrips resistance in onion by considering cultivar response injury, along with cultivar suitability to thrips as a factor in resistance to thrips. These studies developed the idea that tolerance to thrips feeding  rather than resistance to insect infestation  can be a very important resistance mechanism involved in reducing damage to onion crops. A wide range in tolerance to thrips feeding injury was demonstrated, independent of thrips populations on plants and these were expanded into the idea of varietal-based action thresholds that have been promoted in Midwest onion production IPM (Davis et al., 1995). The idea behind this is that some cultivars suffer high yield loss from thrips infestation; others sustain little, if any, yield loss at similar thrips infestation levels. These differences should be reflected in action thresholds used to optimally manage thrips on onions. Recent studies have shown that some of the thresholds currently recommended may, in fact, be too high to avoid some yield loss even without IYSV (Rueda et al., 2007). Additional studies in New York have indicated that thresholds should also be adjusted according to the effectiveness of individual insecticides (Nault et al., unpublished).

No more recent published studies on thrips damage tolerance levels among onion cultivars are known to have been published in the western US. However, this concept has periodically been retested in Colorado studies. For example, 2005-2006 studies established onion plots that were maintained at different action thresholds (5, 15, 30 thrips/plant) through the season. In 2005, the yield response between the plots receiving high thrips maintenance (3-5 insecticide applications) to attempt maintenance of 5 thrips/plant showed a yield response of +19, + 16, -3, and -4% among the cultivars, Aspen, Rumba, Exacta, and Teton, respectively. A similar trial in 2006 showed a yield response difference in onions maintained on a high thrips insecticide management program, applying insecticidal control when thrips populations exceeding 5 thrips/plant, resulting in total yields compared to the untreated plants of +9, + 1, 0, -20% among the cultivars Aspen, Rumba, Renegade and Yula. In both years, concurrent weekly counts of thrips on plants showed modest differences in numbers of thrips per cultivar, with Aspen being among the cultivars supporting the lowest numbers of thrips/plant. These types of studies suggest that some cultivars (e.g., Aspen) are more susceptible to the effects of thrips feeding than are other cultivars (e.g., Yula), and that tolerance to injury is an important thrips resistance mechanism (Mahaffey, 2006; Cranshaw, unpublished data).

It is suggested that a dedicated effort be made to exploit this tolerance mechanism by screening a broad collection of onion cultivars and advanced breeding lines for relative tolerance to thrips feeding. With this information, existing onion cultivars can be categorized for relative risk of yield loss from onion thrips infestation. Such information can be used to guide cultivar selection by growers and crop consultants. This information can also be incorporated into varietal-based action thresholds for treatment, as developed by Al-dosari (1995) and subsequently promoted in Colorado and the Midwest (Davis et al., 1995). Following identification of sources of tolerance to thrips within existing germplasm, more long-term studies can be conducted. Mechanisms of resistance as well as the gene sources that confer such resistance may be identified. This information could be used in onion breeding programs so that thrips tolerance becomes a characteristic incorporated routinely into new cultivars. Furthermore, since the plant tolerance mechanism(s) does not involve selective genetic pressure on onion thrips, this cultural change should provide a more sustainable means of managing thrips damage in onion crops.

The epidemiology of IYSV and its thrips vector are largely unknown, and the literature is devoid of IYSV management recommendations. However, preliminary studies in Colorado, Idaho, and Oregon, have documented that onion cultivars and color classes differ widely in their susceptibility to IYSV infection and tolerance to thrips feeding. For example, IYSV incidence was measured in more than 40 cultivars evaluated in northern Colorado in 2003 and 2004 and in Washington in 2004. Disease incidence ranged from 16 to 100% in the Colorado trial (Gent and Schwartz, 2004) and 58 to 97% in the Washington trial (du Toit et al., 2005), suggesting host tolerance and/or resistance may be available in commercially-accepted cultivars.

In the preliminary Colorado cultivar trials, leaf color was associated with IYSV incidence; cultivars with dark green or blue-colored leaves were typically the most susceptible to IYSV. Other preliminary studies have noted that differences among onion cultivars in cuticular wax content and plant vigor are associated with thrips preference and IYSV symptom expression (Terry 1997; Mohan, Jensen, and Shock, unpublished; R. Watson, personal communication). We have also identified onion cultivars with tolerance to thrips feeding which thus require less frequent insecticide applications for thrips (and presumably IYSV) management. In preliminary studies conducted in 2003 and 2004, we observed that several cultivars with partial resistance to IYSV also possessed some degree of thrips feeding tolerance. Combining IYSV resistance with thrips tolerance may be a sustainable management strategy to reduce or eliminate conventional insecticide use, but a more focused and intensive effort is essential to identify commercially acceptable cultivars that will be readily adopted by growers.

Objectives

1. Screen onion germplasm for improved levels of tolerance to Iris yellow spot virus (IYSV) and thrips
   
2. Study the biology and epidemiology of IYSV and thrips, and impacts of chemical, cultural and biological tactics that can reduce their impacts upon onions.
   
3. Transfer information on progress dealing with IYSV and thrips biology and IPM strategies to the onion industry and other interested parties
   

Methods

Objective 1, Onion IYSV/Thrips Evaluation Nursery Protocol - Uniformly evaluate and report the reactions of onion entries (advanced breeding lines, cultivars, germplasm accessions) when exposed to Iris yellow spot virus and thrips populations under field and controlled conditions. This nursery is available to all allium industry personnel including those involved with university, USDA and seed company projects. We encourage regional participation of these nurseries, at 4 to 6 sites. Promising materials will be promoted for use in onion cultivar improvement efforts by public and private onion breeders. Participants will include scientists from: CO, ID, NM, NY, OR, TX, WA, and USDA-ARS. Germplasm Evaluation Nursery Design: The Germplasm Evaluation nursery will initially be limited to 20 to 25 entries in addition to the standard checks. Randomized, split-block design with 3 replicates; main block planted on 2 beds (1 or 2 lines per bed), 2 meters in length, with 1 bed treated with an insecticide(s) to control thrips and the other bed left untreated, with a 1 m alleyway between blocks. Plant every third row with an IYSV/Thrips susceptible border that is not treated with any insecticide to provide more uniform pest pressure adjacent to each 2-bed plot of the germplasm accession. Surround nursery by a border (3 meters) of a local onion variety that receives all agronomic inputs except for insecticide treatments. Cooperators are encouraged to plant in an area with a history of IYSV and moderate to high thrips pressure. IYSV pressure may be increased by promoting development of IYSV infected volunteers, transplanting infected plants into and around the nursery. Split-block treatment may include: A. Untreated control and B. Fipronil (Regent) seed treatment or soil drench + foliar insecticides. Other than the insecticide treatment, the nursery should receive standard grower practices for herbicides, fungicides, fertilizer and irrigation. Plant Population will be thinned to 18 emerged plants/linear meter per line to provide a minimum of 36 plants per line per treated and untreated plot. Thrips Population Counts: Without removing plants, count the average number of adult and larval thrips / plant on 10 plants for each entry & treatment at 4 weeks pre-bulbing, 2 weeks pre-bulbing, bulbing, 2 weeks post-bulbing, 4 weeks post-bulbing. IYSV Evaluation Scale: Without removing plants, estimate the IYSV ratings for each entry & treatment at bulbing, 3 weeks post-bulbing, and 6 weeks post-bulbing. Record % incidence as proportion of 25 plants exhibiting symptoms of infection, and severity as an average rating of infected plants (Severity classes: 1 = 1-2 small lesions, 2 = 3-10 medium lesions, 3 = 11-25 medium to large lesions, and 4 = more than 25 medium to large lesions per infected leaf). Objective 2, IYSV and Thrips Biology and Management Research. Collaborators will follow conventional and proven scientific and biological approaches for the study of the insect, virus and their interaction in field, greenhouse and laboratory settings. When possible, follow the methods outlined above for the Nursery Protocol in terms of experimental design, minimum plot size, pest sample periods and evaluation tools. Methodologies will include the use of scientifically accepted molecular tools such as DAS-ELISA (based upon AGDIA technology) and PCR/rt-PCR protocols developed by various laboratories, in addition to applied tools that are accepted by scientific societies and peer-reviewed publications. Specific thrips and virus protocols will be based upon methods that already been employed by project participants, and it is anticipated that collaborative activities and meetings will enable participants to develop and test proven protocols and modify protocols as more data and experiences occur in the upcoming years. Participants will include scientists from: CO, GA, ID, MN, NY, OR, TX, UT, WA, WI, and USDA-ARS. It is vital that we identify potential sources of the virus and its vector in and around onion production systems to effectively design and implement effective pest management strategies. Using GPS/GIS technology, survey transects (10 to 25 km in length) will be established in major onion production areas with a history of IYSV, with 5 to 10 sites (fields that typically vary in size from 5 to 25 hectares each) per transect. Plant samples (10 to 25 representative individuals of the target species from in and around the sample field) will be collected (as aliquots of leaf, seed, stem tissues), stored on ice, and transported/mailed to the nearest laboratory for assay with ELISA and RT-PCR (confirmation of ELISA positive samples). Target plants will include wild Allium species and other members of the Liliaceae. Surveys will concentrate on the weed species which are commonly encountered in onion production fields. Thrips will be counted from a bulked composite of 10 randomly selected onion plants at each plot grid on a 2 - 4 week interval. Representative thrips will be washed from plants using 70% ethanol, collected in a small glass vial containing 70% ethanol, and later classified to the species level. If a project objective is to study viruliferousness of recovered thrisp, a subsample (10 thrips larvae) of the predominant thrips species will be recovered from targeted plots in a water (not alcohol) wash, separated to species, transferred to Nicotiana benthamiana, and incubated for 3 to 4 days prior to leaf tissue harvest and testing with the ELISA and/or rt-PCR protocol(s). Record % incidence of IYSV as proportion of 25 plants exhibiting symptoms of infection; it is suggested that disease readings be taken at bulbing, 3 weeks post-bulbing, and 6 weeks post-bulbing. Objective 3, Annual Meeting: W 2081 (WDC 7) will hold annual meetings to update participants on current research, share information on new outbreaks and ongoing concerns with onion virus (IYSV) and thrips problems, identify potential sources of support for research needs, prioritize research needs, establish cooperative approaches to research needs, pursue successful grant applications that involve stakeholders and end users, and assign committees to address specific virus and/or thrips related issues as needed. Every other year, e.g., 2008 (Georgia), 2010 (to be selected), and 2012 (to be selected) our committee will schedule its meeting in conjunction with the 2-3 day long National Allium Research Conference. Formal and informal participation at these meetings is encouraged from all participants as a means of updating information and providing new information on onion virus (IYSV) and thrips problems. Participants will include scientists from: CO, MN, NY, OR, TX, UT, WA, WI, and USDA-ARS. Peer-reviewed research and extension publications, in addition to articles in trade magazines such as Onion World are also encouraged as a way to communicate with peers and growers. Information will be shared with collaborators in a common database that will be accessible via the web site at www.alliumnet.com

Measurement of Progress and Results

Outputs

• Local and exotic germplasm, possessing traits useful to the U.S. onion production, will be converted to temperate adaptation and released to the public. This germplasm will provide researchers with novel genes to broaden the genetic base of U.S. onion cultivars (e.g., new resistance or tolerance genes to biotic stresses with an emphasis on IYSV and thrips).
• A detailed understanding of the extent and nature of genetic diversity of the pathogen causing economically important diseases such as Iris yellow spot virus in the U.S. will be obtained. Similarly, new alternative methods of detection, inoculation, and/or screening environments for the virus and thrips pests will be developed and serve as standardized protocols across the industry. Together, this will help determine the most appropriate inoculation method and the number and type of strains/isolates of the virus and biotypes of thrips and species that need to be used for breeding and selection. Also, the potential utility of molecular diagnostic tools and genetic fingerprinting for detecting and monitoring pest diversity in the U.S. will be established.
• The genetic base of resistance will be broadened; and new germplasm, improved breeding lines and cultivars of major onion market classes will be screened. The improved breeding lines and cultivars will possess increased levels of tolerance to IYSV and/or thrips. Concurrently, molecular markers for new resistance or tolerance alleles and QTL for these pests will be generated from this project.

Outcomes or Projected Impacts

• Identification of priority research issues and development of cooperative strategies to obtain funding, conduct research and transfer results to the other industry and other interested parties.
• Identification of new strains of IYSV or biotypes of thrips affecting onion and other alliums, and dissemination of information concerning such pests to members of W-x and the onion industry.
• Uniform testing of onion germplasm, breeding lines, and cultivars for reactions to IYSV and thrips will provide scientists and growers with objective information on host toler-ance and selection of less susceptible materials for various onion classes and production regions.
• Exchange of ideas and information through the use of annual meetings, brief publications, and a dedicated web site (www.alliumnet.com) specifically directed at interested clientele.
• Acting as a resource group, which would provide advice and recommendations to impact policy related to germplasm importation and utilization of transgenic resistance and germplasm pertinent to IYSV and thrips issues.
• Outcome/Impact 6 Improved high yielding onion cultivars with increased tolerance to IYSV and/or thrips may dominate the regional and national production. Area planted to new cultivars may increase by more than 10% leading to substantial yield increases in the participating states. Commercial value of new cultivars may exceed $100 million annually. Outcome/Impact 7 Adoption of multiple-pest resistant cultivars may reduce pesticide use by 25% or more resulting in savings to the producers and impacting positively to healthier environments. Outcome/Impact 8 Development of sustainable, biologically-based IPM practices to manage thrips/IYSV.

Milestones

(2007): Submit a formal request to create a regional research committee, and invite participation by all interested agricultural experiment stations, USDA-ARS projects, and onion commodity groups.

(2008): Implement an Onion IYSV/Thrips Evaluation (AITE) Nursery to systematically evaluate onion germplasm in multiple locations in the U.S. - Initiate development of transgenic plants with improved levels of resistance to IYSV - Work towards improved virus diagnostics with refinement of ELISA and PCR - Expand knowledge on hosts of IYSV - Technology transfer posted at www.alliumnet.com web site

(2009): Develop inoculation protocol - Expand knowledge on biological & molecular properties of the virus strains - Identify stress factors involved in expression of IYSV in onion - Describe virus movement within the plant - Describe field relationship between virus and thrips on onion

(2010): Expand knowledge base on thrips species roles as a pest and/or vector - Develop regional IYSV Risk Index Model - Develop regional IYSV & Thrips IPM Strategies

(2011): Evaluate transgenic plants for reaction to IYSV - Validate regional IYSV Risk Index Model - Validate regional IYSV & Thrips IPM Strategies

(2012): Validate regional IYSV Risk Index Model - Validate regional IYSV &Thrips IPM Strategies - Share published information on IYSV and/or thrips with the onion industry

Projected Participation

View Appendix E: Participation

Outreach Plan

OUTREACH PLAN: Research results from each sub-project will be published in refereed and non-refereed journals, extension bulletins, and flyers; and posted on the web sites of individual institutions or programs, e.g., www.alliumnet.com. Germplasm, breeding lines and cultivars will be tested statewide, regionally, and nationally (e.g., the Onion IYSV/Thrips Evaluation Nursery), including on-farm, strip-plantings of the most promising or outstanding genotypes in different production systems. Field days will be held each year at or near crop maturity. In addition, the most important findings will be shared with all interested parties through workshops, news media, and electronic sources such as the dedicated web site at www.alliumnet.com.

An annual report, including identified research priorities for the region, plus individual summaries from each participant at the annual meeting will be generated. Minutes of the meeting and the annual report/summaries will be sent to committee members and archived on the dedicated web site. In addition, the annual report will be sent to appropriate University Deans and Agricultural Experiment Station Directors, key legislators, and identified clientele, i.e., onion grower groups within the region. A one page review of committee activities and its role will be submitted to major onion industry magazines such as Onion World for grower information.

The following clientele groups will be engaged by W-2081: National Onion Association California Garlic and Onion Dehydrator Colorado Onion Association Columbia Basin Vegetable Seed Growers Association (Washington) Georgia Fruit and Vegetable Growers Association Grand Canyon Sweet Onion (Arizona) Idaho-Eastern Oregon Onion Committee Idaho Onion Growers Association Malheur County Onion Growers Association Michigan Onion Committee New Mexico Dry Onion Commission New York State Onion Growers Association New York State Vegetable Growers Association Noonday Onion Growers Association (Texas) Pacific Northwest Vegetable Association South Texas Onion Committee Texas Produce Association Utah Onion Association Vidalia Onion Committee Walla Walla Sweet Onion Marketing Committee Washington Potato and Onion Association Western Oregon Onion Commission Wisconsin Muck Farmers Association Onion Seed Companies: Nunhems, American Takii, Bejo, Crookham, Seminis, etc. Pesticide Companies: BASF, Dupont, Syngenta, etc.

Organization/Governance

W-2081 will hold annual meetings to update participants on current research, share information on new outbreaks and ongoing concerns with onion virus (IYSV) and thrips problems, identify potential sources of support for research needs, prioritize research needs, establish cooperative approaches to research needs, pursue successful grant applications that involve stakeholders and end users, and assign committees to address specific virus and/or thrips related issues as needed.

Formal and informal participation is encouraged from all participants as a means of updating information and providing new information on onion virus (IYSV) and thrips problems. Recent and upcoming publications are also identified.

Present officers of the W-2081 Regional Project are: Chair, H. F. Schwartz , Colorado State University plant pathologist, Fort Collins, CO. Vice-Chair, Chris Cramer, New Mexico State University onion breeder, Las Cruces, New Mexico. Secretary, Stuart Reitz, USDA-ARS-CMAVE entomologist, Tallahassee, Florida. The directors of the various participating state institutions designate the W-2081 participating researchers, who in-turn elect the Members or officers of the Technical Committee. The project is considered a Western Regional Research Project, but has substantial participation by states in other onion producing regions of the U.S. and USDA-ARS researchers. The Technical Committee officers are a Chairperson, Vice-Chairperson, and Secretary. Unless he/she declines to serve, the Vice-Chairperson will succeed the Chairperson. The Secretary is elected annually and the previous Secretary will succeed the Vice-Chairperson, unless he/she declines to serve. An election will be held if any officer declines to serve in his/her office. The officers will be elected from the officially designated representatives, and may serve consecutive years if re-elected by the committee members. The Western Association of Agricultural Experiment Station Directors select the Administrative Advisor who has no voting rights.

The Technical Committee will meet annually, unless otherwise planned, at a place, and on a date designated by a majority vote of the committee. Minutes will be recorded and an annual progress report will be prepared by the Technical Committee and submitted through proper channels.

Literature Cited

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2. Al-dosari, S.A. 1995. Development of an IPM system for onion thrips (Thrips tabaci Lindemann) as a pest of bulb onions. Ph.D. Colorado State University. Ft. Collins, CO. 124 pp.

3. Boyd, V. 2003. A jumbo threat. The Grower 36 (9):10-11, Lenexa, KS.

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7. Coudriet, D.L., Kishaba, A.N., McCreight, J.D. and Bohn, W.G. 1979. Varietal resistance in onions to thrips (Thysanoptera, Thripidae). J. Econ. Entomol. 72:614-615.

8. Cranshaw, W. S. 2006. Colorado Insecticide Trials for Control of Thrips on Onion, 1995-2006. Colorado State University Agricultural Experiment Station Report. In press.

9. Creamer, R., Sanogo, S., Moya, S., and Romero, J. 2004. Iris yellow spot virus on onion in New Mexico. Plant Dis. 88:1049.

10. Crowe, F. J., and Pappu, H. R. 2005. Outbreak of Iris yellow spot virus in onion seed crops in central Oregon. Plant Dis. 89:105.

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