Growth Characteristics by Plug Tray Cell Size, Soil Type, and Fertilizer Concentration for Plug Seedling Production of Veronica pusanensis Y.N. Lee

Background and objective: This study was conducted to establish a stable seedling production system for Veronica pusanensis Y.N. Lee, a plant that is endemic to the Korean Peninsula and is a critically endangered species, distributed along the coast of Busan, Korea. Methods: In order to investigate the plug cell size (72, 128, 200 cells), soil type (commercial substrate, and mixed substrates with peat moss and perlite at ratios of 1:1, 3:1, and 4:1), and fertilizer concentration (Peters 0, 500, 1,000, and 2,000 mg⋅L-1) conditions, the plug tray was filled with soil and seeds were sown. The sown trays were placed in the growth chamber (25°C, 70% RH, PPFD 100 μmol⋅m-2⋅s-1) for three repetitions per treatment. Results: There was no difference in the growth of seedlings according to plug cell size. Therefore, it appears to be economically superior to produce seedlings in a 200-cell plug tray. In soil type, the seedling growth increased as the ratio of peat increased, but leaf chlorosis occurred from the 7th week after sowing. Examining the growth of seedlings based on fertilizer concentration, the greatest increase in growth was found to have occurred in the 1,000 mg⋅L-1 treatment. Conclusion: Therefore, for the production of V. pusanesis seedlings, it was noted that when mixed soil with peatmoss and perlite at a ratio of 4:1 is filled in 200-cell plug trays, and the seedlings are fertilized with Peters 1,000 mg⋅L-1 once a week, growth will increase the most, demonstrating excellent cost-effectiveness. However, to mass-produce high-quality seedlings in a short period, it will be necessary to use a plug tray smaller than 200 cells or to conduct various fertilization composition studies.