Abstract
The objective of this study was to classify Japanese alfalfa varieties using fall dormancy ratings(FDR). In 2004 and 2005 fall dormancy tests were carried out at three research fields of National agricultural research center for Hokkaido region, located in Sapporo, Memuro and Monbetsu. Nine Japanese cultivars, eleven breeding strains and thirteen foreign cultivars including nine check cultivars were used in this study. The FDR of Japanese alfalfa cultivars for the warmer regions ranged from 5.9 to 7.0. On the other hand, FDR of those for the cold regions ranged from 2.2 to 5.3. The range of FDR was greater in cold region cultivars than those of warmer region cultivars. The FDR of Haruwakaba was smallest in cultivars for the cold regions, which suggested that adaptability to the cold regions was the greatest in Haruwakaba. We discussed advantages of the FDR method over previous mehods in classification of Japanese alfalfa cultivars.
