Effect of Cell Size on Growth and Development of Plug Seedlings of Three Indigenous Medicinal Plants

Abstract

There have not been many studies conducted on the seedling production, especially in plug trays, of traditionalmedicinal plant species. In an effort to establish guide lines for seedling production, this study investigated the effect ofplug cell size on the growth and development of plug seedling of three medicinal plant species. Seeds were sown in either128, 200, or 288-cell plug trays, containing a commercial medium. Growth and development of individual seedling wasgenerally promoted with increasing size of a plug cell in all of the three species. The greatest biomass of the seedlingsgained in a plug tray was obtained in the 288-cell trays in Perilla frutescens var. acuta Kudo and Sophora tonkinensis, andthe 200-cell trays in Angelica gigas Nakai. Overall growth and development of the shoot and root of a single seedling ofPerilla frutescens var. acuta Kudo, except total chlorophyll and anthocyanin contents, was the greatest in the 128-cell tray. However, length of the longest root, length, width and area of the leaf, internode length, root fresh weight, and root ball formationin the 200- and 288-cell trays were not significantly different each other. In Sophora tonkinensis, although length ofthe longest root, stem diameter, leaf width, leaf area, shoot fresh weight, and root ball formation were not significantly differentamong the treatments, length of the longest root and root ball formation of a single seedling were the greatest in the128-cell tray. Overall shoot and root growth, except total chlorophyll content, of a single seedling of Angelica gigas Nakaiwas the greatest in the 128-cell tray. Based on the total biomass, it is concluded that 288-cell trays are recommended forproduction of plug seedlings of medicinal plant species P. frutescens var. acuta Kudo and S. tonkinensis. In A. gigas Nakai,it would be more economical to use the 200-cell trays than 128-cell trays due to total biomass.