Perennial ryegrass seed, produced for sale as turf and forage grass seed, is grown in rural agricultural areas of northern Minnesota and contributes $15-20 million to rural economies annually. As a perennial, perennial ryegrass has many environmental benefits in a crop rotation including decreased erosion, reduced leaching, high organic matter production, and greater habitat for wildlife due to fewer tillage operations. From a farmers standpoint, perennial ryegrass is a desirable crop rotation option because it is profitable, tolerant of diverse weather conditions, requires less labor than annual crops, and harvest occurs earlier than for annual crops so labor requirements are spread throughout the season. Minnesota farmers have indicated that crown and stem rust pathogens are a severe issue in seed production fields (causing up to 80% yield reduction) and that new cultivars that are resistant to crown and stem rust pathogens would be desirable. Currently the only way to control rust pathogens is to spray fungicides which are costly and harmful to human and environmental health. The goal of my research is to develop a method for rapid, and accurate selection for resistance to rust pathogens in perennial ryegrass germplasm based on plant chemical compounds (a “metabolic fingerprint”) associated with rust resistance. Termed metabolomics-assisted breeding, this technique will lead to faster rust resistant cultivar development, ultimately reducing fungicide use and making perennial ryegrass seed production a more profitable, marketable and sustainable option for farmers in rural communities in northern Minnesota as well as the Pacific Northwest and Canada.