Agricultural robots and automated machinery for handling of nursery seedlings with special reference to the transplanting devices

Agricultural robots have become need of the hour due to sharp escalation in wages of labor for agricultural operations. Hence, there is demand for more precise application-based machinery. Transplanting is the most drudgery-prone and time-consuming operations which is mostly done manually. This review presents the recent advances in the arena of robotic transplanting and automated machinery for handling nursery plants/seedlings. Many semi-automatic transplanters were developed, which demand manual labour for feeding seedlings into cups, resulting in reduced efficiency. Due to shortage of labor during peak season, automation in transplanting operations is very much essential to ensure the timeliness of operation. Robotic-based automatic transplanter may be an alternative for transplanting nursery plants/seedlings. A systematic search was conducted from online database using different keywords in three stages i.e. the initial level, the segregation level, and the final level. The specific keywords used were “Robotic transplanter”, “Seedling pick-up device”, “Manipulator”, “Extractor”, “End-effector”, “Gripper”. Out of 175 articles, 70 were shortlisted and included in the study which are mainly focused on transplanting devices using robotics and automation mechanisms. The transplanter reported to have a robotic arm/manipulator, a seedling pick-up device, an end-effector, and/ or a vision or sensor-based system. However, the robotic technology may appear to be expensive but its use can be justified due to the non-availability of labour or the high labour cost and to ensure timeliness of repetitive field operations. Looking into the future prospects of these technologies, research should be oriented toward the advancement of next-generation robots for field applications.