1. Quantum is a synthetic variety with 62 parent clones. Parent clones trace to 19 populations selected for resistance to the following pests: bacterial wilt, Fusarium wilt, Verticillium wilt, Phytophthora root rot, anthracnose and Aphanomyces. Phenotypic recurrent selection was used. Final selections were made from 2-year-old space-plant
selection nurseries at Marshfield and Livingston, Wisconsin, based on vigor, leafhopper yellowing resistance, leaf disease resist