Abstract:

【Objective】 To develop a geometrical attribute model of leaf blade based on dry weight (DW), which is the output of growth model. 【Method】 Firstly, the model was deduced from the relationship between biomass and geometrical parameters of leaf theoretically. And then, based on observations on leaf length and leaf width of different leaf positions (LP) on main stems under different nitrogen rates and densities with four cultivars (LY108, 86Y8, NJ43, YD 6), the change patterns of specific leaf weight (SLW) with leaf position and the relationship between leaf length and width of rice on main stem were analyzed. 【Result】 The results indicated that the relationship between leaf blade length and width could be expressed in power function, and SLW changed with the leaf position (LP) in quadratic equation. 【Conclusion】 The validation of the model with independent experimental data under different nitrogen rates and densities with four cultivars showed that the RMSE of dynamic leaf length and leaf width on main stem were 2.55 cm and 0.06 cm, respectively, and the model could be used in simulating the geometrical characteristics of rice leaf blade on main stem under different growth conditions.

Key words: rice, biomass, leaf length, leaf width, specific leaf weight