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183 1. Breeding program was initiated at Woodland, California, in February 1963, with establishment of a thinly seeded nursery plantings of Moapa and Sonora. A very heavy epiphytotic of downy mildew (Peronospora trifoliorum) occurred, killing or severely injuring nearly two-thirds of the seedlings. Approximately 2,000 healthy surviving seedlings were thinned to a single-plant basis and evaluated during the summer, 1963, for leafiness, foliage color and recovery after 28-30 day interval top-growth removal. By fall, approximately 200 plants had been chosen as superior in forage characteristics. In spring 1964, a total of 135 single plants were chosen primarily on spring vigor of which 94 traced to Moapa and 41 from Sonora origins. Rooted cuttings of these 135 plants were established for evaluation of forage and seed. In fall 1964, 31 clones were chosen, established as rooted cuttings in the greenhouse, and tested for antibiosis resistance to ENT-B of spotted alfalfa aphid. Twenty were highly resistant. During the winter 1964-65, a complete diallel was made by hand crossing to obtain seed of 190 possible F1 crosses among the 20 parental clones. In addition, each of the 20 clones was self-pollinated to obtain sufficient seed for S1 progeny evaluation. Sufficient F1 seed was obtained to test all 190 crosses in 4 replications with 16 plants per replication, spaced 1 foot apart in rows 1 foot apart. This forage trial was harvested three times in 1965, and six times in 1966. Several experimental synthetics of superior clones were made up in cages in 1966 for testing in 1967, of which one was subsequently increased and distributed as 183. 2. Sacramento and San Joaquin Valleys in California and in Mexico as a variety to be used for hay production. 3. Blue flowers with variations in shades of color from light to dark blue. Comparable to other varieties in normal variability as a synthetic. Fall dormancy very similar to Moapa. Upright, tall in growth habit. Susceptible to ENT-F spotted alfalfa aphids and to pea aphids. 4. Breeder seed is produced by compositing seed from the vegetative multiplication of eight parental clones grown in isolation. Breeder seed fields are inspected by the California Crop Improvement Association. Breeder seed field stands remain for only 2 years. Foundation seed is produced in California from breeder seed in isolation, as specified by AOSCA. Stands for foundation seed remain for only 2 years. Certified seed can be produced from foundation seed or from breeder seed. 5. Fall 1971.
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