Abstract: A system (1) for modulating growth or attributes of at least one part (2) of one or more plants comprising chlorophyll is disclosed. The system (1) comprises at least one light emitting device (3), such as a light emitting diode (LED), for irradiating the at least one part (2), at least one light sensor (4) for picking up light from the at least one part (2), communication capabilities (5) for facilitating communication between the at least one light sensor (4), the at least one light emitting device, and a processor (6). The processor (6) reads data from the at least one light sensor (4) via the communication capabilities (5), generates a control signal based on the data and a reference, and then controls, based on the control signal, the at least one light emitting device (3) via the communication capabilities in order to modulate plant growth or plant attributes.

Abstract: A system (1) for modulating growth or attributes of at least one part (2) of one or more plants comprising chlorophyll is disclosed. The system (1) comprises at least one light emitting device (3), such as a light emitting diode (LED), for irradiating the at least one part (2), at least one light sensor (4) for picking up light from the at least one part (2), communication capabilities (5) for facilitating communication between the at least one light sensor (4), the at least one light emitting device, and a processor (6). The processor (6) reads data from the at least one light sensor (4) via the communication capabilities (5), generates a control signal based on the data and a reference, and then controls, based on the control signal, the at least one light emitting device (3) via the communication capabilities in order to modulate plant growth or plant attributes.

Abstract: An apparatus and method for determining the photosynthetic activity of a plant by determining the chlorophyll fluorescence of the plant is provided. The apparatus includes a light impermeable housing, a light to illuminate the housing, a light intensity in the housing and to adjust the light intensity controller. The light intensity may be between zero and 700 micromoles of photons per square meter per second. The monitor may be a photodiode protected by light filters which permit only light of wavelengths corresponding to plant fluorescence emission to pass to the photodiode. A computer analysis of the data obtained, corrects for Dark and Straylight signals in the housing and normalizes the data by correcting for the Fo fluorescence.