Abstract
A fast-maturing carrot cultivar that produces small storage roots termed “mini carrot” was grown in a solid substrate, sub-irrigation culture system placed in a phytotron glass room with a controlled air temperature of 23°C and relative humidity of 70%. Patterns of storage root growth and accumulation of chemical compounds in the roots were investigated. Optimal time for harvest determined by the root size was limited to 1 week—between 9 and 10 weeks after seeding. Fresh weight of the storage root increased by the greatest amount between 8 and 9 weeks after seeding. However, increase in length, diameter, and fresh weight of the storage roots reached a plateau at 11 weeks after seeding. The increase in β-carotene and sucrose content was slow until 9 weeks after seeding—just before the optimal harvest time. Thereafter, accumulation of these nutrients became more active, and their contents increased by approximately 2-fold at 3 weeks after the optimal harvest time.
