Fig. 1
From: An evaluation of inexpensive methods for root image acquisition when using rhizotrons
Four different methods were used to take images of walnut tree roots in rhizotrons: a flatbed scanner, b handheld scanner, c smartphone scanning application and d time-lapse camera. In (d), the time-lapse camera and rhizotron were placed into insulated boxes so that variations in temperature did not affect root growth. In the other rhizotrons, insulating material was placed over the rhizotron Plexiglas pane and removed before scanning