Differentiating wheat varieties with different leaf angle distributions using NDVI and canopy cover

Ten winter wheat varieties (Triticum aestivinn L.) with different leaf angle distributions (LAD) were used in this experiment. Results showed that varieties with planophile LAD had a leaf orientation value (LOV) ranging from 25.12 to 40.33 while varieties with erectophile LAD had LOV ranging from 67.5 to 73.25. The canopy spectral reflectance was measured using a ground-based spectroradiometer. Normalised difference vegetation index (NDVI) and canopy cover were compared for the two types. The results indicate that at the jointing stage, the planophile varieties presented higher canopy spectral reflectance than the erectophile ones in the near infrared region. However, in the visible wavebands, the erectophile varieties had higher reflectances than the planophile ones. The difference between the two types was greatest at the jointing stage for canopy spectral reflectance, NDVI and canopy cover. Discriminant analysis validated the results that simultaneous measurements of NDVI and cover can be used to differentiate leaf angle distribution of wheat at the jointing stage.