Influence of Temperature on the Growth of Three Cultivars of Alfalfa (Medicago sativa L.)

HARADA Isamu

doi:10.14941/grass.21.169

Two experimental parts for influence of temperature on the growth of three cultivor of alfalfa, were conducted and are discussed as part I and part II. One-year-old plants of "Vernal", "Cody", and "Florida 66" were grown in three growth chambers set at different temperature regimes ; (1) hot (H) 32℃ during the day and 27℃ at night ; (2) warm (W) 27/21℃, and ; (3) cool (C) 21/15℃ All chambers had an 18-hour photoperiod of ca. 21, 500lux (ca. 6.3g Cal/cm^2/hr.). In part I, plants were harvested on a time basis. Each variety were harvested, when "Florida 66" reached first flower at 27 days. In the second part, all cultivars were harvested, when each variety reached first flower. In part I, the maturity of three cultivar was delayed as temperature decreased from 32/27℃ to 21/15℃. Shoot height and weight of plant parts for each cultivar were greatest in the (W) regime. The highest weight of all plant part was obtained in (W) regime except for weight of root and crown, followed in descending order by the (H) and (C) regimes. Total plant yield was highest in the (W) regime and was progressively lower in order with the (H) and (C) regimes. TNC concentrations of leaves and stems were increased as temperature decreased. Among cultivars, "Florida 66" had the highest concentration of TNC, in each plant part, while differences between "Cody" and "Vernal" for concentrations of TNC were insignificant. In part II, "Vernal", "Cody", and "Florida 66" reached the first flower stage after 27 to 32 days in the (H) regime, after 32 to 36 days, in the (W) regime, after 42 to 49 days in the (C) regime. "Vernal" flowered significantly later than the "Florida 66" and "Cody" in all three temperature regimes by 3 to 5 days. Average shoot height for each cultivar at the first flower stage was greatest in the (W) regime followed in descending order by plants in the (C) and (H) regimes, but there were no significant differences among cultivars. The highest weight of all plant at the first flower stage for three cultivars was obtained in the (C) regime, except for weight of stem from "Cody." Among cultivars the highest weight were obtained in the "Vernal" except for weight of roots in the (W) regime. Total plant yield was highest in the (C) regime and progressively lower in the (W) and (H) regime, and among cultivars, "Vernal" alfalfa was highest. The TNC concentrations of leaves and crown were highest in the (C) regime, except crown of "Vernal." There were no significant difference in percentage of TNC of stems and roots in the three regimes. Plant growth rate (mg/pot/day) of leaves and roots were increased as temperature decreased. Among cultivars, the rate of "Vernal" was highest, and the difference between "Cody" and "Florida 66" was not clear. The accumulation rate for leaves and stems was highest in the (C) regimes and among cultivars "Vernal" was higher than the others.

Influence of Temperature on the Growth of Three Cultivars of Alfalfa (Medicago sativa L.)

Bibliographic Information

Search this article

Description

Journal

Details 詳細情報について

Export

Report a problem