OPTICAL METHOD FOR ASSESSING THE FUNCTIONAL STATE OF PLANTS Russian patent published in 2021 - IPC A01G7/04 G01N33/00 G01N21/64 

FIELD: agriculture.

SUBSTANCE: invention can be used to assess the functional state of plants, including when optimizing agrotechnical growing conditions, as well as to identify plant resistance to various unfavorable environmental factors. The method includes measuring the optical parameters of leaves. The intensity of light scattering of a leaf blade of a plant is recorded during the first illumination with monochromatic optical radiation of the red region of the spectrum of 630-660 nm with power density of 80-120 W/m² for 3-6 seconds in the transmission mode. Then, monochromatic probe radiation of the blue region of the spectrum of 450-470 nm with power density of 400-1200 W/m² is activated, and within the next 60 seconds, the dynamics of changes in the intensity of chlorophyll fluorescence in the reflection mode is recorded. The relative content of chlorophyll is judged by how the leaf weakens the probe flow in the red region of the spectrum, and the photosynthetic activity is judged by the change in the intensity of chlorophyll fluorescence for 60 seconds of illumination of the probe flow in the blue region of the spectrum. The functional state of plants is judged by the value of the СFS index that is calculated by the formula: CFS = (I_f3-I_f60) /I_r4 where I_f3 is the intensity of the fluorescent signal in the reflection mode at the 3rd second of exposure to monochromatic blue light; I_f60 is the intensity of the fluorescent signal in the reflection mode at the 60th second of exposure to monochromatic blue light; I_k4 is the intensity of light scattering of the leaf in the transmission mode at the 4th second of illumination with monochromatic red light. In this case, the higher the CFS value is and the lower the I_k4 value is, the greater the specific photosynthetic activity is and the higher the relative chlorophyll content is; and the lower the CFS value is and the higher the I_k4 value is, the lower the specific photosynthetic activity is and the lower the relative chlorophyll content is in the leaves.

EFFECT: method provides a reduction in the labor intensity of determining the functional state of plants and an increase in its efficiency by means of quantitative assessment of photosynthetic activity and the relative content of chlorophyll in one measurement cycle.

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