Journal of Hunan Ecological Science

【Objective】This study aims to clarify the mechanism by which plug seedling rearing affects the seedling quality of leafy mustard (Brassica juncea) and to identify a suitable technical system for mechanical transplantation, providing theoretical support for standardized seedling rearing and variety selection. 【Method】Using three varieties—Huarong Large-leaf Mustard ( T1), Purple-veined Mustard (T2), and Huajie No. 11 (T3)—the growth characteristics of 30-day-old seedlings under plug and bed seedling rearing were systematically compared. Fourteen parameters were measured, including agronomic traits (leaf number, leaf length / width, stem diameter, plant height, root length), biomass indices (whole-plant fresh / dry weight, root-to-shoot ratio), and strong seedling performance (transplanting sur- vival rate, seedling vigor index). A two-way ANOVA was performed to assess interactive effects. 【Re- sult】The seeding rearing method significantly regulated seedling growth: plug seedlings exhibited superior root development, with root length increased by 60. 85% - 72. 51% , root dry weight enhanced by 16. 79% -22. 70% , and root-to-shoot ratio elevated by 65. 67% -82. 31% compared to bed seedlings. Transplant survival rates (increased by 2. 28% -2. 57% higher) and seedling vigor indices (increased by 10. 10% - 24. 92% greater ) were also significantly improved. Conversely, bed seedlings showed dominant aboveground growth, with leaf length / width, plant height, stem diameter and biomass exceeding plug seedlings by 2. 22% -71. 25% . The comparison of varieties showed that the indexes of T3 were significantly better than those of T1 and T2, and the seedling index of plug seedlings was 0. 401, which was 18. 99% and 31. 48% higher than that of T1 and T2, respectively. 【Conclusion】Plug seedling cultivation can significantly enhances stress resistance and transplant adaptability through optimized root development and root-to-shoot coordination. Huajie No. 11 exhibits the best performance due to heterosis. This study confirms that plug seedling rearing technology meets the stringent quality requirements for me- chanical cultivation and is recommended as the optimal standardized protocol for leafy mustard produc- tion.

leafy mustard; growing seedling in hole tray; mechanization; agronomic characters; Huajie No. 11