The detection and identification of plant diseases
is crucial for an appropriate and targeted application of
plant protection measures in crop production. Recently,
intensive research has been conducted to develop innova-
tive and technology-based optical methods for plant dis-
ease detection. In contrast to common visual rating and
detection methods, optical sensors are able to measure
pathogen-induced changes in the plant physiology non-in-
vasively and objectively. Several studies showed that
especially hyperspectral sensors are valuable tools for
disease detection, identification and quantification on dif-
ferent scales from the tissue to the canopy level. This
review describes the basic principles of hyperspectral
measurements and different types of available hyperspec-
tral sensors. Possible applications of hyperspectral sensors
on different scales for disease detection and plant protec-
tion are discussed and evaluated. The advantages and dis-
advantages on each particular scale, as well as the impact
of external factors, such as: light, wind, viewing angle, for
measurements in laboratories, greenhouses and fields, are
critically assessed in order to support researchers and
agriculture technicians. Additionally, a comprehensive lit-
erature review about the use of hyperspectral sensors on
these different scales for plant disease detection reflects the
possibilities of non-invasive measurement systems. This
highlights advantages of hyperspectral sensors when
investigating plant–pathogen interactions through multiple
examples. By some approaches, detection before visible
symptoms appear is feasible. The potential of hyperspectral
sensors as a tool for disease identification and quantifica-
tion, based on disease characteristic changes in the plants
spectral signature, is discussed as well. The review is
concluded with an overview on different data analysis
methods, which are required to extract key information
from gathered hyperspectral datasets.