Since 1954, the spotted alfalfa aphid has severely damaged alfalfa in California, Arizona, and Nevada. Plant breeders and entomologists from all three states have worked to develop Sonora—a new variety, resistant to the aphid and high producing, particularly in winter and early spring. The purple-flowered, upright-growing Sonora recovers rapidly after cutting and is adapted to areas of the Southwest, formerly planted to African, where winter forage production is desired.