A method and a device for making images of the quantum efficiency of the photosynthetic system with the purpose of determining the quality of plant material and a method and a device for measuring, classifying and sorting plant material

摘要

A method for determining the quality of plant material is achieved by determining a chlorophyll fluorescence image of said plant material. The plant material is irradiated with a beam of electromagnetic radiation comprising one or more such wavelengths that at least a part of the chlorophyll present is excitated by at least a part of the radiation. The beam of electromagnetic radiation has such a shape that only a small part of the plant material is irradiated, and the beam is moved over the plant material such that a larger part of the plant material is measured. The fluorescence radiation originating from the plant material associated with the chlorophyll transition, is measured with an imaging detector for obtaining a chlorophyll fluorescence image. In any order, during a certain duration of time several fast scans are made over the plant material with the electromagnetic beam for obtaining a chlorophyll fluorescence image Ffast, and during a certain duration of time a slow scan is made over the plant material with the electromagnetic beam for obtaining a chlorophyll florescence image Fslow, and subsequently the characteristic chlorophyll fluorescence image that is a measure for the efficiency of the photosynthetic system of plant material is calculated from the chlorophyll fluorescence images Ffast and Fslow.