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US 12,596,070 B1Granted
Monitoring chlorophyll fluorescence and green light reflectance to detect plant stress
AssigneeMjnn LLC
InventorsTessa Hilary Pocock, Matthew Robert Urschel
Life of this patent
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Abstract
Methods and systems for remote detection of growth conditions of a plant species. In a particular implementation, the present invention provides improved techniques for identifying one or more stress conditions in plants, including without limitation, drought stress, temperature stress, salinity stress and other conditions in a plant species. An example implementation assesses both steady-state chlorophyll fluorescence and green light reflectance of a plant species in real-time. A controller may detect drought and/or other stress conditions by comparing the respective signal trajectories of observed chlorophyll fluorescence and green light reflectance.
Claims12
An apparatus for monitoring one or more growing conditions of a plant, comprising:
- a controller;
- one or more excitation light sources operably connected to the controller, each of the excitation light sources operable to emit an excitation light in response to an excitation control signal transmitted by the controller, the excitation light having an emitted light spectrum operable to induce chlorophyll fluorescence (“ChIF”) from a plant species;
- a detection module operably connected to the controller and comprising
- a first photodetector operable to detect an amount of excited ChIF light from the plant species and convert the detected excited ChIF light into an excited detection electrical signal, the excited ChIF light emitted from the plant species in response to receiving the excitation light;
- a second photodetector operable to detect an amount of green light reflected from the plant species and convert the detected reflected green light into a reflected detection electrical signal, the reflected green light emitted from the plant species in response to ambient or controlled lighting conditions;
- wherein the controller is operable to
- determine chlorophyll fluorescence data based, at least in part, on the excited detection electrical signal;
- determine green light reflectance data based, at least in part, on the reflected detection electrical signal;
- cause the one or more excitation light sources and the detection module to repeat detecting of ChIF and green light reflectance at periodic intervals;
- and
- a computing system programmed to detect one or more plant stress conditions of the plant species based on monitoring of the ChIF and green light reflectance detected over an analysis period by
- determining a first signal trajectory of the ChIF detected over the analysis period;
- determining a second signal trajectory of the green light reflectance detected over the analysis period;
- mapping the first and second signal trajectories against one or more combinations of reference signal trajectories, wherein each of the one or more combinations of reference signal trajectories includes a reference signal trajectory for ChlF and a reference signal trajectory for green light reflectance and corresponds to a plant stress condition of the one or more plant stress conditions;
- and
- selecting the plant stress condition from the one or more plant stress conditions based on the mapping the first and second signal trajectories against the one or more combinations of reference signal trajectories, wherein
- a first plant stress condition of the one or more plant stress conditions comprises drought stress, and wherein the combination of signal trajectories associated with the first plant stress condition comprises a reference signal trajectory for ChIF that diverges from the reference signal trajectory for green light reflectance, and
- a second plant stress condition of the one or more plant stress conditions comprises high temperature stress, and wherein the combination of signal trajectories associated with the second plant stress condition comprises a reference signal trajectory for ChIF that follows the reference signal trajectory for green light reflectance.
15 more elements
An apparatus for monitoring one or more growing conditions of a plant, comprising:
- a controller;
- one or more excitation light sources operably connected to the controller, each of the excitation light sources operable to emit an excitation light in response to an excitation control signal transmitted by the controller, the excitation light having an emitted light spectrum operable to induce chlorophyll fluorescence (“ChIF”) from a plant species;
- a detection module operably connected to the controller and comprising
- a first photodetector operable to detect an amount of excited ChIF light from the plant species and convert the detected excited ChIF light into an excited detection electrical signal, the excited ChIF light emitted from the plant species in response to receiving the excitation light;
- a second photodetector operable to detect an amount of green light reflected from the plant species and convert the detected reflected green light into a reflected detection electrical signal, the reflected green light emitted from the plant species in response to ambient or controlled lighting conditions;
- wherein the controller is operable to
- determine chlorophyll fluorescence data based, at least in part, on the excited detection electrical signal;
- determine green light reflectance data based, at least in part, on the reflected detection electrical signal;
- cause the one or more excitation light sources and the detection module to repeat detecting of ChIF and green light reflectance at periodic intervals;
- and
- a computing system programmed to detect one or more plant stress conditions of the plant species based on monitoring of the ChIF and green light reflectance detected over an analysis period by
- determining a first signal trajectory of the ChIF detected over the analysis period;
- determining a second signal trajectory of the green light reflectance detected over the analysis period;
- mapping the first and second signal trajectories against one or more combinations of reference signal trajectories, wherein each of the one or more combinations of reference signal trajectories includes a reference signal trajectory for ChIF and a reference signal trajectory for green light reflectance and corresponds to a plant stress condition of the one or more plant stress conditions;
- and
- selecting the plant stress condition from the one or more plant stress conditions based on the mapping the first and second signal trajectories against the one or more combinations of reference signal trajectories, wherein
- a first plant stress condition of the one or more plant stress conditions comprises drought stress, and wherein the combination of signal trajectories associated with the first plant stress condition comprises a reference signal trajectory for ChIF that diverges from the reference signal trajectory for green light reflectance, and
- the reference signal trajectory for ChIF is a downward signal trajectory and the reference signal trajectory for green light reflectance is an upward signal trajectory.
15 more elements
Dependencies are inferred from the claim text.