A high quality low-cost digital microscope minirhizotron system

An easily reproducible system is presented for minirhizotron image acquisition based on a digital microscope and entirely built with low-cost components. The system weighs 2.28 kg, is connected to a portable computer through USB, and allows collection and storage of high-quality digital images without other components or power sources. Settings at 25× magnification provide pixel sizes of 25 and 12 μm respectively with a medium pixel density microscope (640 × 480 pixel), and a high pixel density microscope (1280 × 1024 pixel). This kind of system coupled with recent developments of robotics and automatic image analysis for minirhizotron frames allows to envisage fast, low-labour and low-cost root investigation methods with a high degree of automation.

► We describe a medium to high resolution minirhizotron image acquisition system and provide details for reproducing it.
► The system is based on digital microscopes of 0.37 or 1.3 MPixels and led lights.
► Only one component is carried in the field and it is powered through a USB port.
► Twenty five micron per pixel were attained in medium resolution and 12 μ in high resolution.
► The system allowed more than 7 h of operation when connected to a six lithium cell netbook.