Selection and cultivation of introduced alfalfa varieties in NorthSichuan region

The production performances of introduced 11 alfalfa （Medicago sativa） cultivars in NorthSichuan region of China were evaluated by using the comprehensive evaluation model of grey relevancy theory based on seven main indexes, including fresh forage yield, dry forage yield, the ratio leaf to stem, plant height, branch number, main root length and regrowing rate. A comprehensive evaluation model was established in the study. By analyzing the data using the model, the results showed that the order of weight of seven indexes was fresh forage yielddry forage yieldthe ratio of leaf to stemplant heightbranch numbermain root lengthregrowing rate. Cultivars of Hunter river, Hoopuland and WL323 had relatively good productive performances, while Afliter, Terry and Farmers treasure had poor performances. Although Emperor and Victoty had higher fresh forage yields, but the comprehensive evaluation scores were low because of their slower regrowing rate, lower ratio of leaf to stem and dry material contents.