DOI: 10.5061/dryad.bk3j9kddv
title: Data from: Emerging wild virus of native grass bioenergy feedstock is well established in the Midwestern USA and associated with premature stand senescence

description: This dataset includes values for the prevalence of switchgrass mosaic
 virus (Genus Marafivirus, Family Tymoviridae) detected with molecular
 diagnostics (RT-PCR) in individual Panicum virgatum (switchgrass) plants
 and in Graminella leafhoppers that feed on them. Surveys were conducted in
 15 sites in August 2012. Stands surveyed had been established for some
 time and represent a range of landscape contexts. Measures of stand height
 and percent senescence were also collected. Land cover composition
 surrounding each site was calculated from the USDA-NASS Cropland Data
 Layer and estimates of drought impact were derived from the US Drought
 Monitor.
description: <strong>Field collections and laboratory
 analysis</strong> Plant and leafhopper samples
 were collected in the field during the 2012 growing season. Virus
 infection was detected within samples using RT-PCR with specific primers.
 Detailed methods are described in the associated manuscript.
 <strong>Land cover analysis</strong>
 For land cover analysis, we evaluated relevant regions from the
 USDA National Agricultural Statistics Service Cropland Data Layer. 2012.
 Published crop-specific data layer [Online]. Available at
 https://nassgeodata.gmu.edu/CropScape/. USDA-NASS, Washington,
 DC. Land cover types included within each aggregate
 category We grouped all raster cells as belonging to
 one of the following eight broad land cover groups: Agriculture: Alfalfa, Apples,
 Barley, Blueberries, Carrot, Cherries, Corn, Cucumber, Dry Beans, Grapes,
 Oats, Onion, Potatoes, Pumpkins (1.5 km only), Radish, Rye, Soybean,
 Squash, Sugarbeet, Sunflower, Watermelon (1.5km only), Winter
 Wheat<br>Barren: Barren<br>Forest: Deciduous Forest, Evergreen
 Forest, Mixed Forest<br>Grass/Meadow: Fallow Cropland,
 Grassland/Pasture, Other Hay, Sod/Grass Seed<br>Developed:
 Developed/High Intensity, Developed/Medium Intensity, Developed/Low
 Intensity, Developed/Open<br>Miscellaneous Perennial Habitat:
 Shrublands, Clover/Wildflowers<br>Open Water: Open
 Water<br>Wetlands: Herbaceous Wetland, Woody Wetlands
 Following Werling et al., 2011 (Werling, B. P., T. D. Meehan, B.
 A. Robertson, C. Gratton, and D. A. Landis. 2011. Biocontrol potential
 varies with changes in biofuel-crop plant communities and landscape
 perenniality. Global Change Biology Bioenergy 3:347-359), we created an
 additional aggregate category, which contains elements from several
 categories above: Herbaceous perennial habitat:
 Alfalfa, Other Hay, Fallow Cropland, Shrubland, Clover/Wildflowers,
 Grassland/Pasture To quantify how much drought each
 study site experienced, we calculated a drought index value based on
 spatially-explicit estimates of the duration and weekly severity of
 drought conditions as published in the US Drought Monitor
 (https://droughtmonitor.unl.edu/). Description of methods as excerpted
 from our associated article: "The Drought Monitor rates moisture
 conditions as no drought or dryness (no drought rating), abnormally dry
 (D0), moderate drought (D1), severe drought (D2), extreme drought (D3),
 and exceptional drought (D4). For each site’s GPS location (i), we thus
 calculated a Drought Index (<em>DI)</em> as <br>where <em>j</em> = the growing season week, and d<em><sub>j</sub></em> = the Drought Monitor D value rating (0 – 4) for week <em>j</em>. Thus, weekly ratings of D0, D1, D2, D3, and D4 were valued as 1, 2, 3, 4, and 5 respectively. Weeks with no recorded drought or dryness were valued as 0. Switchgrass in this region typically sprout in early May, so we calculated DI for the 16 weeks from the week of May 1 through the week of August 14, when early August field measures were completed (i.e., n = 16)."
description: <strong>Abbreviations used in field names (full
 descriptions of fields are provided in README
 file):</strong> Samples were collected in two
 periods in August 2012. In field names, the first period (August 2-8 or
 early August) is referred to as 8a12 and the second period (Aug 23-29 or
 late August) as 8b12. LH = leafhopper
 prev = prevalence gram = Graminella
 aureo = G. aureovittata oqmo = G. oquaka and
 G. mohri PC = percent Mn
 =mean <strong>Data set</strong>
 NA = missing data