Difference of production performance of alfalfa varieties grown on winterfallow farmland in Nanjing

In order to select high yield and quick growth of alfalfa cultivars used in south China，the yield components and dry matter of 8 weak fall dormancy alfalfa cultivars were studied in a winterfallow farmland in Nanjing. Dry matter yields of 8 alfalfa cultivars were 730.26-1 460.25 g/m2 determined by harvesting 2 times in next spring. Plant height，primary shoot number and crop growth rate are important factors in dry matter yield. At the first cutting，dry matter yield was positively correlated significantly with plant height, internode number per caulis, primary shoot number and crop growth rate. At the second cutting，dry matter yield was positively correlated with crop growth rate, plant leaf area, stem diameter, primary shoot number, plant height, growth rate of plant height and branch number. Four cultivars including WL414，WL525HQ，Siriver and Derby had high potential that would to be used in south China as higher dry matter yield resulted from more plant height, primary shoot number and crop growth rate.