Method for estimating leaf SPAD (soil and plant analyzer development) values of winter wheat after regreening and before earing

The invention discloses a method for estimating leaf SPAD (soil and plant analyzer development) values of winter wheat after regreening and before earing. The method comprises steps as follows: (1), canopy image collection and analysis: winter wheat canopy is subjected to digital image collection, and canopy image color parameters are obtained; (2), SPAD value determination of field leaves: after collection of the digital images of the winter wheat canopy, SPAD values of unfolding leaves at the topmost part are determined by an SPAD-502 chlorophyll meter in a digital image collection area, and an average value is calculated; (3), estimating model construction: an SPAD value estimating model is constructed with an integrated neural network method according to the SPAD values of the winter wheat leaves and the corresponding canopy image color parameter data; (4), estimating model verification: the estimating model is verified with correlation coefficients, root-mean-square errors and relative root-mean-square errors. The leaf SPAD value estimating model based on winter wheat canopy image analysis is constructed with the integrated neural network method, so that accuracy of SPAD value monitoring of the winter wheat leaves is effectively improved.