Seasonal variation of the canopy structure parameters and its correlation with yield-related traits in sugarcane.

Population structure determines sugarcane yield, of which canopy structure is a key component. To fully understand the relations between sugarcane yield and parameters of the canopy structure, 17 sugarcane varieties were investigated at five growth stages. The results indicated that there were significant differences between characterized parameters among sugarcane populations at different growth stages. During sugarcane growth after planting, leaf area index (LAI) and leaf distribution (LD) increased, while transmission coefficient for diffuse radiation (TD), mean foliage inclination angle (MFIA), transmission coefficient for solar beam radiation penetration (TR), and extinction coefficient (K) decreased. Significant negative correlations were found between sugarcane yield and MFIA, TD, TR, and K at the early elongation stage, while a significant positive correlation between sugarcane yield and LD was found at the same stage. A regression for sugarcane yield, with relative error of yield fitting less than 10%, was successfully established: sugarcane yield = 2380.12 + 46.25 × LD - 491.82 × LAI + 1.36 × MFIA + 614.91 × TD - 1908.05 × TR - 182.53 × K + 1281.75 × LD - 1.35 × MFIA + 831.2 × TR - 407.8 × K + 8.21 × MFIA - 834.50 × TD - 1695.49 × K (R (2) = 0.94**).