トウキ栽培に適した紙筒育苗技術の開発

抄録

Angelica acutiloba, the source plant of the crude drug Angelicae acutilobae radix, has been cultivated throughout Japan for centuries. However, traditional outdoor seedling cultivation has disadvantages, such as the difficulty of securing the required number of high-quality seedlings unless the farmer has high skills and many years of experience, and the additional burden of digging up and selecting seedlings during the busy season in early spring. Using commercially available paper pots, we developed a seedling-raising technique for A. acutiloba, aiming to reduce the labor involved in growing and planting seedlings. From four experiments conducted over a four-year period, we demonstrated that 1) the optimal paper pot size is 3.0 cm in diameter and 15 cm in height, 2) the most suitable fertilization method is to mix fertilizer with fermented oil cake (N:P:K = 4:6:2) into the seedling soil at 200 mg/L of nitrogen content, 3) blue light is effective as additional lighting, and 4) when seedlings are grown under the above conditions for 14-22 weeks, the yield is equivalent to that of traditional seedling cultivation. Paper pot seedlings have the advantages that they can be planted mechanically while retaining the fine roots and moisture of seedling soil, allowing them to take root quickly after transplanting, and that the taproot develops straight so that it takes on a shape similar to that of seedlings produced conventionally.