Quantitative identification of yellow rust in winter wheat with a new spectral index: Development and validation using simulated and experimental data

•Wheat pigment and water contents decrease with increasing disease severity.•PROSPECT-D was used for spectral response analysis under yellow rust infestation.•Sensitive band to fungal spores is feature band specific to wheat yellow rust.•Performance of the new index (yellow rust optimal index, YROI) has superiority.