Development and optimization of an automatic transplanting device for plug tray vegetable seedlings using embedded...

Timely seedling transplantation, though crucial for horticulture, is increasingly becoming uncertain due to seasonal labour shortages, limited mechanization, and higher import and repair costs of automated vegetable transplanters in India. A simple and cost-effective vegetable transplanting device with automatic plug-tray seedling extraction feature was designed and developed considering very limited studies on simple and indigenous automatic seedling extractor design. The developed extractor uses a mechanical toggle mechanism for robustness and a close loop-controlled embedded system to drive it for optimum performance. The crank rotational speed, seedling root bulb moisture content, and needle penetration depth in root bulb were major affecting factors optimized using the RSM to maximize extraction ratio and minimize failure ratio. The seedling extractor performed optimally at an extraction rate of 38 seedlings per minute, bulb moisture content of 75%, and needle penetration depth of 30 mm. The field testing of the transplanting device with the automatic extractor resulted in seedling extraction ratio of 96.05% and field efficiency of 91.8% at 34.62 and 35.47 plantings.min^- 1, respectively, for tomato and cabbage seedlings, saving 92.2% time than the conventional manual method. The developed system holds promising prospects for timely and cost-effective vegetable transplanting in India and developing nations.