WL 220
1. WL 220 is a synthetic nearly equal to Vernal in fall dormancy in the northern latitudes, but considerably less so in the central midwest. It is comprised of 214 survivors of screening tests for resistance to spotted alfalfa aphid, pea aphid, and Phytophthora root rot. Parentage traces to WL 311, WL 318, WL 215, WL 219, and other advanced WL germplasm with multiple pest resistance.
2. WL 220 is a hay and haylage type cultivar to be merchandised in the northern region of adaptation. It is currently being tested in Ohio, Michigan, northern Illinois, southern Wisconsin, central Iowa, Minnesota, and Nebraska.
3. Flowers are approximately 75% purple, 20% variegated, 3% yellow, and 2% white. WL 220 possesses high resistance levels to bacterial wilt and pea aphid, moderate resistance to Phytophthora root rot, anthracnose, and biotypes of the spotted alfalfa aphid found in the San Joaquin Valley of California. Reaction to stem nematode has not been determined.
4. Seed production shall be on a three generation basis: breeder, foundation and certified. Sufficient breeder seed was produced in Kern Co. Calif., and is maintained in environmentally controlled storage. Breeder seed, the composite harvest from 214 parent clones interpollinated under cage by honey bees, will be planted in the northern region of adaptation to produce foundation seed. Certified seed will be produced from either breeder or foundation seed. No other generation or class of seed will be recognized.
5. Marketed fall 1978.
6. Application for Plant Variety Protection is unlikely.