Growth characteristics and their correlation with yield for 10 varieties of Medicago sativa were evaluated from 1999 to 2002 under space sowing at Lanzhou, China. The peak period of growth for Medicago sativa occurred in the third year. The greatest increase in dry matter yield occurred before the first cutting, and the fastest daily average increase in height occurred before the second cutting. The coefficients of variance for yield properties among varieties from highest to lowest were leaf area> total dry matter 〉annual average increase height/day. Among years, the highest coefficient of variance for total dry matter and leaf area occurred in the 1~(st) and 4~(th) years, and in the 2~(nd) year for daily increase in height. Between cuttings, the highest coefficient of variance for dry matter yield and increase height/day occurred in the second cutting of the 4~(th) year and in the second cutting of the 3~(rd) year, respectively. The correlation analysis showed that the total dry matter for the 10 varieties very significantly positively correlated to yield components in the 2~(nd), 3rd and 4~(th) years, among which annual dry matter yield in the 3rd and 4~(th) years had the greatest influence on total dry matter yield.
Acta Prataculturae Sinica
dry matter yield