Abstract: Based on the data of the field experiments with four wheat varieties and five level of the nitrogen application,the relationships of the canopy reflectance spectra with the wheat yield and yield components were analyzed.The results showed that the correlation of the canopy multispectral reflectance between theoretical and actual yields was significant at the jointing stage.Therefore,it could be used to estimate the yield.However,the correlation of the canopy hyperspectral reflectance and yield was significant,so it couldn't be used to estimate the yield directly.The panicle number per mu was well forecasted by using canopy multispectral/ hyperspectral reflectance.The canopy multispectral and hyperspectral reflectance were linearly related to panicle number per mu at the jointing,mid-filling and maturity stage of wheat(p<0.01).Thus,the estimate equations of the canopy hyperspectral reflectance A(760,850)/R550 and multispectral reflectance RVI(810,560) were constituted.The research results provided the important references for choosing appropriate canopy reflectance indexes,constituting the yield estimate model and ensuring the precision of the hyperspectral remote sensing information retrieval.

Key words: Wheat, Wheat, Canopy multispectral reflectance, Canopy hyperspectral reflectance, Yield, Yield components