Foliar hyperspectral identification of butternut canker infection in pure and hybridized butternut (Juglans cinerea)

Forests globally are threatened by native and non-native pathogens and pests. Butternut (Juglans cinerea L.) is a hardwood tree species native to North America that currently faces population declines due to butternut canker disease (BCD) by the non-native causal fungus Ophiognomonia clavigignenti-juglandacearum. Developing approaches to detect the presence of BCD in butternut and distinguishing between butternut and hybridized trees will be crucial for accelerating a butternut BCD-resistance breeding program. We found shifts in spectral profiles that were related to disease and species, but that spectral separation of disease presence was similar across species. These findings suggest the capability of foliar hyperspectral data to aid in disease detection in an endangered tree species with significant implications for developing high throughput breeding approaches.