Abstract:

The growth rhythm of Cinnamomum cassia Presl annual seedlings was studied to provide a basis for its production and management, and to improve the quality of cinnamon seedlings out of the nursery. On the basis of regular observation, the growth dynamics, biomass accumulation, growth indexes and distribution law of Cinnamomum cassia Presl at seedling stage were studied, and the growth model of seedling height and ground diameter was established. The results showed that: the growth process of Cinnamomum cassia Presl annual seedlings could be divided into 4 stages, including seedling emergence stage, early growth stage, rapid growth stage and late growth stage. The growth of seedling height at rapid growth stage was 8.58cm, accounting for 52.59% of the annual growth. The growth of ground diameter at rapid growth stage was 0.029 cm, accounting for 67.44% of the annual growth. The biomass of stems and leaves was greater than that of roots for cinnamon annual seedlings, with a ratio of 7:3, indicating that the growth center of cinnamon was above the ground. Therefore, Logistic equation can be used to predict the growth of seedling height and ground diameter in the growing period and provide a theoretical basis for formulating reasonable seedling culture measures. From May to September, the seedling height grows rapidly, and the application amount of nitrogen fertilizer should be increased. From October to November, the seedling height grows slowly, and the ground diameter is still in the rapid growth stage, the application of nitrogen fertilizer should be stopped, and phosphorus and potassium fertilizer should be applied to promote the lignification of seedlings. From March to April of the following year, compound fertilizer with balanced nitrogen, phosphorus and potassium can be applied.

Key words: Cinnamomum cassia Presl, seedling height, ground diameter, growth rhythm