Raspberry plant stress detection using hyperspectral imaging

Abstract

Monitoring plant responses to stress is an ongoing challenge for crop breeders, growers, and agronomists. The measurement of below-ground stress is particularly challenging as plants do not always show visible signs of stress in the above-ground organs, particularly at early stages. Hyperspectral imaging is a technique that could be used to overcome this challenge if associations between plant spectral data and specific stresses can be determined. In this study, three genotypes of red raspberry plants grown under controlled conditions in a glasshouse were subjected to belowground biotic stresses (root pathogen Phytophthora rubi and root herbivore Otiorhynchus sulcatus) or abiotic stress (soil water availability) and regularly imaged using hyperspectral cameras over this period. Significant differences were observed in plant biophysical traits (canopy height and leaf dry mass) and canopy reflectance spectrum between the three genotypes and the imposed stress treatments. The ratio of reflectance at 469 and 523 nm showed a significant genotype-by-treatment interaction driven by differential genotypic responses to the P. rubi treatment. This indicates that spectral imaging can be used to identify variable plant stress responses in raspberry plants.

Exogenous Cytokinin 4PU-30 Modulates the Response of Wheat and Einkorn Seedlings to Ultraviolet B Radiation

“…UV-B caused a significant decrease in chlorophyll and carotenoid content while 4PU-30 treatment resulted in higher pigment values in both studied plants. Our results are in agreement with previous findings showing that the reflectance measured in the visible region is generally affected by the concentration of leaf photosynthetic pigments (chlorophylls, carotenoids, and anthocyanins), while in the NIR region, it is mostly due to light scattering inside the leaf and therefore related to anatomical traits like mesophyll thickness and stomata structure [56][57][58]. Therefore, the differences in the reflectance spectra between wheat and einkorn observed in the NIR region probably represent a genotypic response.…”