Growth dynamics of annual seedlings of Glycyrrhiza uralensis

Objective To study the growth rhythm of height, diameter at ground and the distribution of biomass of annual seedlings of Glycyrrhiza uralensis. Methods Dynamic measurings were carried out after sowing to determine the indexes including the growth quantity and biomass of overground and underground part of annual seedlings of G. uralensis. Results The growing period can be divided into four stages: the emergence phase, initiation phase, prosperous phase, and late phase. The growth quantity during the prosperity period accounted to 63.3% and 50.2% of biomass of the whole year. The growth rate of root was much higher than that of the stem and leaf. The accumulating rate of biomass is the highest during the period of the July 20th to September 20th. The biomass distribution ratio of root, stem, and leaf was 49.02∶17.75∶33.23, and the biomass ratio of underground part to overground part was 0.96. According to regression analysis, the height and diameter at ground were liner correlation with underground biomass and total biomass was individually larger than that of two biomasses of diameter at ground. Conclusion The growth pattern of the height and diameter at ground is accordance with S curve and can be simulated with Logistic equation. The height and diameter at ground is linearly correlation with the underground biomass and total biomass.