Models for estimating foliar Fe and Mn Concentration of Armeniaca vulgaris cv. Luntaibaixing using spectral reflectance

Aimed at providing technology for a rapid nutrition diagnosis system of micronutrients in Armeniaca vulgaris cv.Luntaibaixing,we established an element concentration estimation model for its foliar ferrum(Fe)and manganese(Mn)concentration based on spectrum analysis.The foliar spectrum reflectance at various phenological periods of fruit development under different soil fertility conditions was measured by Unispec-SC spectrometer.By analyzing the correlation of foliar Fe,Mn concentration at various phenological periods of fruit development,the spectrum reflectance Rλand its first-order differential f′(Rλ),we filtered out its sensitive bands.And we established an element concentration estimation model for its foliar Fe and Mn at various phenological periods of fruit development with the linear regression model.The results showed that the spectral sensitive bands of foliar Fe in fruit setting period were 873 and 874nm,375 and 437nm in fruit core-hardening period,836 and 837nm in maturity period and 325 and 1 054 nm in post-harvest period.However,the spectral sensitive bands of Mn were 913and1 129 nm,425and 970 nm,390and 466 nm,423and 424 nm,respectively.The Fe and Mn concentration of A.vulgaris cv.Luntaibaixing leaves were the most relevant to the first-order differential f′(Rλ)of its spectrum reflectance,whose linear spectrum estimation model fitting degree was the highest and reached to a significant or highly significant level.It showed that the spectral sensitive bands of Fe and Mn element varied with different phenological periods of fruit development.The spectrum estimation models for its foliar Fe and Mn concentration could be established with linear model according to its first-order differentialf′(Rλ).