Grey association degree analysis on the main characters of domestic and overseas alfalfa

Seventeen alfalfa varieties were used to analyze the relationship among their characters with grey relate degree analysis based on the investigation for 3 years. The result showed that the plant height was the most effective factor affecting the yield, and followed by the growth speed, branch diameter and branch number. The effective factor affecting the quality was the growth speed, branch diameter and branch number. The plant height and growth speed were the key characters for the breeding with purpose of high yield. As for high quality breeding, the growth speed, branch diameter and branch number were the key characters.