Few pests attack alfalfa in the Klamath Basin. The main diseases present are bacterial wilt and phytophthora root rot. Verticillium wilt has not been found in the basin, but it occurs in many surrounding areas. The main insect pest is the alfalfa weevil. Some breeding programs are beginning to select for resistance to this pest.
Pest resistances are important variety selection criteria.
Winter hardiness is important in selecting a variety for the Klamath Basin. Local variety trials are being used to develop empirical winter hardiness and stand persistance measurements to supplement fall dormancy ratings as a measure of variety hardiness. Forage yield is a function of a complex set of interactions between the alfalfa plant and its environment. Variety trials conducted at the KES provide alfalfa producers locally developed data on the yield potential and persistence of new alfalfa varieties. An alfalfa variety trial established at KES in 1996 is the subject of this report.