S02 - Session P6 - Comparison of dormancy and early yield of Japanese native taro

Authors: Takeshi Morita *, Yasuyuki Kanie, Yoshinori Nakao, Yasumasa Morita

We aimed to investigate the dormancy and early yield of Japanese native taro to contribute to their cultivation. For the experiments, Ishikawa-wase (a typical early variety used in forced cultivation of taro in Japan), Aichi-wase (early variety), and Ohno-imo (late variety) were used. On May 20, 2015, seed corms of each variety were planted 40 cm apart in an open field and cultivated conventionally. The first harvest was carried out on August 6, 2015, and the number and weight of the main, primary, secondary, and tertiary corms were measured. On the same day, 10 corms of each variety were placed in a polyethylene bag together with horticultural soil and stored at 5 ░C (low temperature treatment) or 20 ░C (room temperature treatment). In the room temperature treatment, germination was observed 2 weeks after the start of the treatment. In the low temperature treatment, the corms were transferred to room temperature 2 months after the start of the treatment, and germination occurred 2 weeks after the transfer. The harvest and germination test were conducted four times from August to November. The yields of Ishikawa-wase and Aichi-wase did not differ significantly until the third harvest. In the fourth harvest in November, Ishikawa-wase showed a significantly higher yield than Aichi-wase. The yield of Ohno-imo tended to be lower than that of the other varieties throughout the experimental period. For all varieties, germination was promoted by storing at 5 ░C for 2 months rather than at room temperature. Thus, all varieties showed dormancy, but the dormancy was released by low temperature treatment for 2 months.