| Abstract: | A new dynamic vegetation index (VI)-yield model, that is, the leaf area duration (LAD)-yield model was structured for estimating winter wheat yield according to the measured reflection spectral data on the wheat field, and the relationship between wheat yield and LAI. The model had the information on the photosynthetic area and time during the later period of wheat growth, i. e., the period from the heading stage to the end of filling stage. The accuracy of the estimated wheat yield arrived up to 98% .In addition, the winter wheat yield was also estimated by a VI-yield model in a given wheat growing stage, and the VI in several main wheat growing stages were used for this purpose. The results suggested that the best season for estimating wheat yield using the VI-yield model was in the middle of wheat filling stage for the case study in Yucheng, Shandong province. The accuracy of the estimation could arrive at 96%. |
