Impact of Rehmannia glutinosa Sprouting on Seedling Quality and Quantity

Background: This study addressed the issues of uneven sprouting and yield reduction in Rehmannia glutinosa when traditionally sown directly into open fields. A plug-tray seedling method incorporating a sprouting process was employed to try and mitigate these problems.<br/>Methods and Results: Sprouting R. glutinosa, the rhizomes were sown into 72-cell standard trays, covered with soil, and maintained at an average daily temperature of 25°C and over 98% humidity. The sprouting periods were set at 3, 4, 5, 6, and 7 days and three cultivation methods were analyzed to compare the effects of sprouting: conventional direct sowing of rhizomes in open-fields, rhizomes plug-tray cultivation, and sprouted rhizomes plug-tray cultivation. The results showed that a 5 days sprouting period was the most effective in terms of shoot length and weight. Sprouted rhizome plug-tray cultivation followed by transplanting significantly outperformed both the conventional direct seeding cultivation in the open-field and non-sprouted rhizomes plug-tray cultivation followed by transplanting, with an underground yield of 2,040 ㎏/10a and a catalpol content of 5%.<br/>Conclusion: Sprouting effectively enhances R. glutinosa yield and quality. Further research is needed to address the challenges of root development in vegetatively propagated crops compared to seed-propagated crops and mechanization studies are required to improve the transplanting efficiency.