Development of Raising Seedling Technology for Veronica pyrethrina Nakai Using Plug Trays

Background and objective: Veronica pusanensis, an endemic species of South Korea belonging to the Plantaginaceae family, is found in Busan, South Korea. Due to its high ornamental value, it is expected to be utilized as a flower crop. However, currently it is an endangered species with its habitats being destroyed and reduced.Methods: Therefore, in this study, we analyzed the growth and photosynthetic responses of potted plants of V. pusanensis under different shading levels to enable mass production. Polyethylene (PE) shading films were selected as the shading material, and shading levels were designed at 0, 35, 45, 60, 75, and 99%, respectively.Results: Results showed that shoot height, shoot width, ground cover, leaf length, leaf width, shoot fresh and dry weight, chlorophyll content (SPAD units), and chlorophyll fluorescence parameters Fv/Fm and PIABS were highest under the 35% shading level. This indicates that it is relatively more desirable to grow V. pusanensis in shade culture compared to under direct sunlight. Meanwhile, root fresh weight and dry weight were highest under the 0% shading level.Conclusion: Therefore, it is recommended to grow V. pusanensis under direct sunlight to significantly increase root biomass when the purpose is to facilitate rootage when transplanting plants for habitat restoration. On the other hand, for the cultivation of V. pusanensis as an ornamental flower crop, it is recommended to grow the plants under the 35% shading level to significantly increase plant sizes and maintain ensure the proper functioning of photosynthetic responses in photosystem II (PSII).

Section: Introductionmentioning

confidence: 99%

An Analysis of the Growth and Photosynthetic Responses of Potted <italic>Veronica pusanensis</italic> Y.N.Lee according to the Shading Levels

Park¹,

Lee²,

Nam³

2023

“…Chlorophyll fluorescence analysis is one of the representative methods used to study plant stress responses (Guidi et al, 2019). It is a technique that analyzes the photosynthetic responses of plants by utilizing various parameters, including F v /F m , Φ Do , ABS/RC, DI o /RC, and PI ABS (Park et al, 2023), and has been proven useful through various studies (Kwon et al, 2021;Lee et al, 2021;2022b;Oh et al, 2021;. A biomass analysis, an older method applied to investigate whether plants have grown soundly, causes irreversible damage to plant roots because the plants are separated from the soil, and it has limitations in that it can only be performed on a one-off basis.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Growth, Flowering, and Chlorophyll Fluorescence Responses of <italic>Viola cornuta</italic> cv. Penny Red Wing according to Spectral Power Distributions

Jang,

Lee,

Shin

et al. 2023

Background and objective: The genus Viola, a member of the Violaceae family, is renowned for its ornamental flower crops. Additionally, Viola species are relatively pest-resistant and easy to manage. They are widely used in gardens, and some of their flowers are even edible. In this study, our focus was on V. cornuta cv. Penny Red Wing (hereinafter referred to as ‘Penny Red Wing’), an experimental plant chosen for its high ornamental value and rapid growth.Methods: We applied a purple light-emitting diode (LED) and three types of white LEDs with varying color temperatures: 3000, 4100, and 6500 K, respectively, as artificial light sources. Notably, a purple LED has a far-red wavelength (700-800 nm) ratio of approximately 17.6% in their spectral power distribution.Results: The findings indicated that several parameters exhibited higher values under purple LED: shoot size parameters, shoot biomass, moisture content of shoots and roots, photochemical reflectance index (PRI), modified chlorophyll absorption ratio index (MCARI), total number of flowers, flower size parameters, scent score, Fv/Fm, and PIABS. However, the 6500 K white LED led to higher evaluations of root length, number of shoots and leaves, root biomass, moisture content of shoots and roots, Fv/Fm, and PIABS. Nevertheless, it was observed that shoot growth was relatively hindered, and the flowering responses were inadequate under the 6500 K white LED, suggesting their unsuitability for the mass production of ‘Penny Red Wing’. Furthermore, the 3000 and 4100 K white LEDs were also deemed unsuitable for cultivating ‘Penny Red Wing’ due to their lower cultivation efficiency.Conclusion: ‘Penny Red Wing’ was evaluated as having superior growth, flowering, and chlorophyll fluorescence responses under purple LED, indicating that the far-red wavelength had a more pronounced effect compared to the green wavelength (500-600 nm). Therefore, we recommend cultivating this cultivar under purple LED, which include the far-red wavelength.

“…As for Impatiens walleriana, an herbaceous flower crop, the larger the cell volume of plug trays, the greater the dry weight and main root length and thickness at the sale stage (Di Benedetto and Klasman, 2004). Veronica pyrethrina Nakai (VPN), a native plant species in the Korean peninsula, showed no difference in the growth of shoots while raising seedlings in plug trays for 6 weeks; but sufficient root pruning for moving was achieved in the smallest plug cell of 10 mL, deriving an effective cell volume with a large number of roots despite the small cell size (Kwon et al, 2021). On the other hand, as Veronica pusanensis Y.N.…”

Section: Introductionmentioning

confidence: 99%

Growth Characteristics of <italic>Hemerocallis thunbergii</italic> Baker Seedlings depending on Cell Size in Sowing using Plug Trays

Park

Yoon

2022

Background and objective: This study was conducted to determine the appropriate cell size, and days after sowing seeds by examining the growth of Hemerocallis thunbergii Baker (HTB) seedlings using plug trays.Methods: The growth of seedlings was examined after sowing seeds in four types of plug trays (143, 70, 18, 13 mL/cell). The sown trays were placed in a greenhouse for three repetitions per treatment. The seedling growth were measured at intervals of one month after sowing.Results: The leaf width and root length increased in proportion to the cell size, and at 90 days after sowing the highest leaf number was observed in the 143 mL/cell plug tray, followed in order by 18, 13, and 70 mL/cell plug tray. The longest leaf length was found in the 70 mL/cell plug trays, followed in order by the 70, 18, 143, and 13 mL/cell plug trays, but there was no significant difference except in 13 mL/cell plug trays. By analyzing the plant water content (PWC) of the shoots and roots, it was found that the PWC of the root system increased as the cell size increased, compared to that of the shoots, and there was a significant difference according to the cell size.Conclusion: Compared with the 143 mL cell plug tray, which had the largest cell size among the other treatment groups, the leaf number increased only for the 18 mL cell plug tray, there was no significant difference from 143 mL cell plug tray, and the leaf length was rather longer. Therefore, considering the actual production period and economic efficiency of raising the seedlings, it is considered that nursery period of 60 days or more is appropriate for HTB based on 18 mL/cell in sowing in plug trays.