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United States Department of Agriculture

Agricultural Research Service

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Research Project: Development of Improved Grape Production and Utilization Practices in the Pacific Northwest

Location: Horticultural Crops Research

2012 Annual Report

1a. Objectives (from AD-416):
The objective of this cooperative research project is to conduct collaborative viticulture research of mutual benefit to ARS and the University of Idaho. The research conducted by the University of Idaho will be complementary to the wine grape research program established by ARS at the University of Idaho’s Parma Research and Extension Center. The broad objective of the ARS program is to investigate integrated, sustainable production practices for development of improved vineyard management strategies and improved end product quality or perceived market value.

1b. Approach (from AD-416):
Investigate critical management and production practices impacting wine grape quality components. Emphasis will be placed on water and canopy management, endproduct processing methods, as well as germplasm evaluation.

3. Progress Report:
This research was conducted in support of objective 305 1B Perennial Crops. Survey of viruses present in wine grapes in Idaho. Idaho has a growing viticulture industry, with nearly 1,600 acres of wine grapes in the state. Production is largely concentrated in two locations, the Snake River valley which primarily includes Canyon County in the southwest, and the Clearwater River valley primarily Nez Perce County in the northwest. Until recently, very limited information was available on the prevalence of wine grape virus in the state. From 2009-2011, a survey of virus presence in Idaho vineyards was conducted, spanning both Snake and Clearwater River valleys. Samples were collected at the end of the growing season, from late September to early November, when leafroll symptoms were expressed in red cultivars. Both symptomatic and/or asymptomatic leaf samples were collected from Cabernet Sauvignon, Cabernet Franc, Merlot, Syrah, Lemberger, Barbera, Pinot Noir, and Petit Verdot cultivars, while only random, asymptomatic leaf samples were collected from white cultivars Chardonnay, Riesling, Pinot Gris, Sauvignon Blanc, and Semillon. Total nucleic acids were extracted from leaf petioles collected, and subjected to RT-PCR tests with primers specific to viruses from the leafroll and rugose wood virus complexes. RT-PCR bands from initially identified positive samples were cloned into a plasmid vector and subjected to sequencing to confirm the initial positive identification. Grapevine leafroll-associated viruses (GLRaV) -1, -3, -4, and -5 from the leafroll virus complex, and Rupestris stem pitting associated virus (RSPaV) and Grapevine viruses A and B (GVA and GVB) from the rugose wood virus complex were found in Idaho vineyards. Grapevine fleck virus (GFkV) was also found in multiple vineyards in Idaho. GLRaV-3 was found the most wide-spread, followed by GVA, GLRaV-1, GVB, and GFkV. Only a few positives were found for GLRaV-4, -5, and RSPaV. No positives were found for two nematode-transmitted viruses, Grapevine fanleaf virus (GFLV) and Grapevine arabis mosaic virus. Prevalence and distribution of viruses differed between individual vineyards and specific cultivars, suggesting significant role played by growers in choosing nursery material, and control methods for vector populations. Evaluation of approaches for food quality component analysis. To improve healthfulness and marketability of products consumed by the general public, a thorough identification of a food’s components are key to discerning how cultivar, environment, post-harvest conditions, processing methods, etc. ultimately influence that food. We are currently investigating alternative ways to improve the appearance of specialty crops by limiting impacts to surface color, by looking at available novel varieties and management practices. This work is currently conducted in collaboration with U of I Parma research and extension center faculty and staffs.

4. Accomplishments

Last Modified: 10/16/2017
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