Reflective spectral characteristics of apple florescence canopy

The apple florescence is a key stage for apple production and management, and the study of apple canopy reflective spectral is of important theoretical and practical significance. Qixia City, Shandong Province was selected as the study area, and reflective spectral data of 120 apple florescence canopies were obtained. Based on the effects of different sample numbers on reflective spectral, the reflective spectral characteristics of apple florescence canopies with and without flowers, with different amount of flowers, at different florescence stages, and with different ages and species of apple trees were systematically studied by using variance and correlation analysis methods. The results indicated that with the increase of cumulative sample numbers, the reflective spectral curves of apple florescence canopies became stable and smooth. In the wave bands of 431-500, 591-680 and 761-1 300 nm, the variance analysis results of canopies with and without flowers were very significant (α=0.01). Results showed that the correlations of canopies with different amount of flowers with reflectances in 391-513, 598-687 and 711-1 193 nm wave bands were significant (p＜0.05). Reflectance increased at the 670 nm Red Valley and decreased in the near-infrared band of 761-1 300 nm with the increase of flower amount. Reflective spectral characteristics among different apple species of Red Fuji, Jinshuai and New Red Star were hard to be distinguished except that for Gala. These results revealed the tremendous potential of capturing information of apple florescence with hyperspectral measurement, and it provided the references for constructing retrieval models of remote sensing.