Abstract: Three millet （Setaria italica Beauv.） plants with the same growth potential of listed plants were selected at each stage of millet growth for the measurement of morphological and biomass parameters of each organ. Based on effective accumulated temperature and Logistic model, the growth model of millet plant height, dry matter mass of overground and leaf area varying with effective accumulated temperature was constructed. The results showed that when the effective accumulated temperature was 700~900 ℃, the millet was in the jointing to booting stage, and the growth rate plant height was the fastest; when the effective accumulated temperature was 1 100~1 200 ℃, the millet was in the heading to filling stage, and the growth rate dry matter weight of the ground was the fastest. When the effective accumulated temperature was 600~800 ℃, the millet was in the jointing to heading stage, and the leaf area growth rate was the fastest. When the effective accumulated temperature was 1 000~1 100 ℃, the value of the millet leaf area reached the maximum. R² values of three modes were 0.989 1, 0.963 6, 0.964 9, the test showed that the models had higher accuracy and better significance. The establishment of a millet growth model based on the effective accumulated temperature can better predict the growth changes of millet height, dry matter above the ground, and leaf area.

Key words: millet （Setaria italica Beauv.）, effective accumulated temperature, Logistic models, extra-green segmentation