Improve Virus Risk Assessment and Vector Management <ol> <LI>Develop a virus risk assessment method for cool season legumes i. Determine virus incidence in host plants and pea aphids from potential reservoirs to the west of the Palouse region <BR>ii. Monitor aphid populations to build on a 24-year record of outbreak incidence and explore these data for patterns of association with meteorological data over the same period. <BR>iii. Determine the temporal and spatial patterns of variation in virus and virus disease in pea and lentil in the Palouse region<BR> iv. Determine the relationship between virus in immigrating pea aphids and the occurrence of virus disease in legume crops<BR> v. Incorporate the information into a procedure for assessing virus risk in cool season legumes <LI>Develop tools for improved virus vector management<BR> i. Develop and refine EILs for pea aphid as a direct pest and virus vector in peas and lentils<BR> ii. Determine the efficacy of selected insecticides for reducing spread of BLRV and PEMV</ol> Breed for Virus-Resistant Cool Season Legumes<ol> <LI> Develop varieties of pea and lentil with resistance to PEMV and BLRV and use marker-assiste<BR>d selection to augment the breeding process <LI>Increase marker density in the genomic region of En and lr for resistance to PEMV and BLRV, respectively. <LI>Establish reliable, high throughput diagnostic tools to characterize and verify virus incidence and disease reaction. </ol> Develop and Extend Crop Protection Practices from Outcomes of I and II <ol> <LI>Develop an advisory group of farmer cooperators. <LI>Educate growers about aphid management and use of project tools. <LI>Assess farmer learning and adoption of aphid management tools from the project. <LI>Disseminate project information through various media.
Non-Technical Summary: The project is a comprehensive and integrated approach to managing aphid vectored viruses of cool season food legumes grown in southeastern Washington State and adjoining Idaho. For decades, unpredictable episodic outbreaks of aphids and the diseases caused by viruses they vector have severely reduced yields of pea and lentil crops in this region. Adapted dry pea and lentil varieties lack resistance to the two most prevalent viruses, Pea enation mosaic virus (PEMV) and Bean leaf roll virus (BLRV), each vectored by the pea aphid Acyrthosiphon pisum. Growers, therefore, typically either prophylactically apply the organophosphate insecticide dimethoate to suppress aphids even when the realized risk of virus infection is low, or they avoid spraying and instead leave the crop open to catastrophic loss when infection risk is high. We address this problem with three integrated research and extension outreach components. The first develops IPM decision tools for producers. These include deriving a virus risk assessment system for pea and lentil based on monitoring immigrating aphids for virus (using reverse transcriptase polymerase chain reaction based detection of viral RNA) and incorporating meteorological data to predict the intensity and timing of aphid flight activity. This first component also develops economic injury levels for direct aphid injury as well as indirect injury caused by the aphid-vectored viruses, and tests alternatives to dimethoate for reduction of indirect injury when indicated. The second component accelerates ongoing efforts to breed resistance to BLRV and PEMV in adapted pea and lentil varieties. These varieties will reduce the need to treat aphids for one or both viruses. The third component educates producers about the IPM tools developed and engages these producers in project activities and product development. The principal investigators include virologists, breeders, entomologists and extension educators from two universities in Idaho and Washington and the USDA-ARS. Results and IPM recommendations will be disseminated via the world wide web, grower newsletters and listserves and workshops. The virus management decision support system will be maintained with industry funds under the guidance of the PD after the project's completion. The project addresses issues covered in the Pest Management Strategic Plan for Pulse Crops. The project also directly addresses RAMP program goals to enhance the development and implementation of innovative IPM strategies for multi-crop food and fiber production systems on an area-wide or landscape scale. <P> Approach: The methods are summarized for each of the three parts of the project: Part I: Improve Virus Risk Assessment and Vector Management Regional surveys for virus sources will be conducted based on sampling the Columbia Basin and points west for aphids and host plants, and examining these for virus using PCR. NOAA weather databases will be examined for relationships with virus outbreak data available over the past 25 years. Aphids immigrating into the Palouse region each year will be monitored using a network of pan traps. Virus incidence in these aphids will be used to construct a risk of virus disease in the crop. Guidelines for treating aphids to control virus spread, when indicated, or to avoid direct injury otherwise, will be developed and promoted to producers. Part II: Breed for Virus-Resistant Cool Season Legumes Existing virus resistant lines will be used to create segregating populations. These will be screened for resistance and a set of resulting lines varying in resistance will be characterized with a high density map of molecular markers. Part III: Develop and Extend Crop Protection Practices from Outcomes of I and II A group of farmer advisors will be established and this group will interact regularly with the research team. Workshops will be held throughout the region to communicate results and advice stemming from the research effort. A web page will be constructed to communicate project results and resulting decision tools to farmers.