Automated Minirhizotron for Non-Destructive Continuous Phenotyping of Root Systems.

Non-destructive continuous measurements of the root system without disturbing the soil and the plant are a challenging task. An automated minirhizotron camera may offer a solution to continuously monitor root development of crops in situ. The aim of the current study is to compare two minirhizotron systems: a regular manually operated system (BTC100, Bartz Technology Corporation) and an automated minirhizotron system. The two minirhizotron (MR) camera systems were compared on tomato (Lycopersicon esculentum Mill, Var. Ka 15) planted in a controlled greenhouse. Measurements included root counts, length, elongation, and distribution and were conducted in 15 days intervals. The automated MR camera recorded significantly more root numbers. The total root length and root length density found significantly higher at0-30   and 40-50 cm depth in the automated MR camera. Root diameter was slightly underestimated by the automated MR at 40-60 cm soil depth. In addition, the automated MR camera recorded higher root elongation rates. This study reveals that the automated MR camera provides precise results of root elongation, root length, and root distribution. The automated MR camera is capable of detecting fine roots differentiate primary and secondary roots. Therefore, the automated MR camera can monitor root development and root zone processes continuously and automatically at real-time. This low-cost automated MR camera will be an excellent solution for non-destructive continuous monitoring of root systems under controlled conditions.