Fig.3Correlation between multi-spectral bands and vegetation index and measured yield in the plot |r| Note: Ⅰ: Elongation stage. Ⅱ: Flag leaf stage. Ⅲ: Flowering stage. Ⅳ: Early grain-filling stage. Ⅴ: Middle grain-filling stage. Ⅵ: Late grain-filling stage. Ⅶ: Wax-ripening stage.