Infrared Imaging for Plant Protection

Abstract

Fungi infections, which may cause variations of plants’ surface tem- perature, can be recognised by infrared cameras in the thermal range (MIR: λ = 8-12 μm) under laboratory conditions. In the field, pro- nounced natural temperature variations of several Kelvin within the crop canopy prevent the recognition of infected plants by commercial thermal vision systems as stand-alone solutions. Near infrared cam- eras ( λ = 0.9-1.7 μm) fitted with band-pass filters show different inten- sity distributions of the reflected radiation. The evaluation of the spec- tral intensity relations improves the differentiation. By NIR several im- portant contents (H 2 O, sugars, acids, etc.) of the surface tissue cells are measured, whereas thermography determines the plant transpiration.