Plant nitrogen status is a key indicator for evaluating crop growth

increasing yield and improving grain quality.Non-destructive and rapid assessment of leaf nitrogen is required for improving nitrogen management in fruit tree production.The hyperspectral reflectance and corresponding total nitrogen concentration of different species of apple trees’ leaves were measured by Field-Spec PMI-MASTER PRO.The correlation among raw hyperspectral reflectance

first derivative spectra

and hyperspectral characteristic variables were analyzed.This paper makes a model for the quantitative detection of leaf ’s total nitrogen with a view to providing a theoretical foundation for nutrition diagnosis of the apple by remote technology.The results showed that the raw spectral reflectance has the maximum negative correlation coefficient at 715nm（r = ?0.817） with total nitrogen concentration and the logarithm model constructed with reflectance at this point is the better one as compared to linear model;the first derivative spectral reflectance has the maximum positive correlation coefficient at 723nm（r = 0.87） and the linear and non-linear models have the similar capacity for the nit rogen est imation;as to hyperspectral characteristic variables

they all show significant correlation with nitrogen contents except λy

SD /SDy and（SDr + SDy）/（SDr ? SDy）.Those results indicate that the variables adopt in this paper have great potential for nitrogen concentration test.By the precision evaluation of estimation models

the logarithm model constructed by the first derivative reflectance at 723 nm was proved to be the best for the estimation of apple leaves nitrogen concentration.