Abstract
Apple proliferation is associated with the presence of the bacterium 'Candidatus Phytoplasma mali'. An infection with this pathogen leads to changes of the physiological state of the apple tree. In this study, it was applied near-infrared spectroscopy to measure these changes. In preliminary analysis based on a quadratic discriminant analysis the first indications that it might be possible to discriminate diseased from uninfected sample material were achieved.