Location: Forage Seed and Cereal Research Unit
Project Number: 2072-21000-051-023-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2021
End Date: Aug 31, 2022
(1) Address long-term threats to hop market access and competitiveness though breeding. Specifically, this will involve breeding of publicly-available germplasm and cultivars with reduced sensitivity to primary pests (twospotted spider mites, hop powdery mildew) that require less pesticide use to produce a high yield with quality of hops. (2) Mitigate short- and medium-term threats to market access associated with regulatory barriers to trade due disparate pesticide Maximum Residue Levels in export markets. Specifically, this will involve analysis of extant datasets to identify factors associated with efficient, low-input production systems, and identification of alternatives to fungicides that may present future barriers to export in the European Union.
Objective (1): Phenotype extant male hop germplasm resources for genetic sources of spider mite and virus/viroid resistance for use in cultivar development. Quantify heritability of these traits and associate genetic loci to phenotypes using genetic markers identified by genotyping-by-sequencing and subsequent association mapping. Crosses will be made with parents possessing desirable traits, progeny screened using traditional methods or newly developed markers, and advanced to field plots for evaluation in the established breeding cycle. Objective (2): Databases developed previously by private sector cooperators and USDA will be interrogated to identify producers that consistently apply more or less fungicides than the industry average. Grower interviews and surveys will be conducted to identify potential predictors to develop a complete data set for analysis. Machine learning algorithms will be applied to identify suites of production factors that are predictive of fungicide use intensity and levels of powdery mildew. Field plots will be established to identify alternatives to fungicides presently used by hop producers in the western U.S. but likely to present trade barriers in the future under the European Union Farm to Fork Policy. Candidate alternatives will be evaluated in a blocking program varied based on mode-of-action and crop phenology. Data from multiple years will be aggregated and analyzed in a meta-analysis to identify programs that provide comparable disease control to current industry standards.