Abstract: Systems, methods and devices for controlling the growth of a plant are described herein. The systems include a photonic sensor and a computing device communicatively coupled to the photonic sensor. The photonic sensor includes an excitation pulse generator configured to generate an excitation pulse of light and direct it towards a target area of a plant. The sensor also includes a lens configured to receive fluorescent light from the target area of the plant and direct the fluorescent light to a focal point, a plurality of optical filters, each being configured to selectively transmit a selected wavelength range of the fluorescent light, the selected wavelength range indicating a molecular activity of the plant, and a photodiode configured to determine an intensity of the selected wavelength range of fluorescent light and convert the measured intensity to a digital signal to be transmitted as molecular activity data to the computing device.