Estimation of Leaf Nitrogen and Grain Protein Content by Hyperspectral Vegetation Index in Winter Wheat

To understand the relationship between hyperspectral vegetation index and wheat leaf nitrogen content as well as grain quality, we studied the correlations between leaf nitrogen content and spectral vegetation indices at different growth stages for two wheat cultivars: high protein content cultivar Zhongyou 9507 and moderate grain protein content cultivar Jingdong 8. At filling stage, significant correlations between wheat leaf nitrogen content and grain protein, dry gluten content were established. Wheat leaf nitrogen content at the different growth stages could be estimated by selected hyperspectral vegetation indices, and the leaf nitrogen content could be further utilized to predict grain protein quality. This research provided some basic understanding for regression models of vegetation index for grain protein prediction by leaf nitrogen content.