Spectral characteristics of winter wheat varieties depending on the development degree of Pyrenophora tritici-repentis

A promising direction in the field of plant protection is the creation of remote sensing methods to detect the development of plant diseases based on the analysis of the reflected radiation spectra. Spectral analysis is a relatively simple non-invasive method that allows to obtain high quality data. The objects of the study were 6 varieties of winter wheat with different levels of resistance to tan spot ( Pyrenophora tritici-repentis ). The purpose of the present study was to assess, in the field conditions, the informativeness of the spectral optical parameters of winter wheat varieties and their mixtures with different susceptibility to the tan spot pathogen. Using the ASD FieldSpec 3 Hi-Res spectroradiometer, high-precision ground-based measurements of selected plant objects were carried out. Analysis of changes in the morphology of spectral signatures of the studied objects showed that the most promising spectral ranges for detecting the development of tan spot at the early stages are 1445–1775 nm and 2050–2450 nm. According to the results of univariate analysis of variance, the influence of wheat varieties and the degree of disease development was confirmed. The hypothesis that the less resistant the wheat variety to tan spot is, the faster is the decrease in the spectral brightness coefficient (SBC) values in the near infrared range of the spectrum and the increase in the red range of the spectrum was confirmed.