Abstract
Studies were carried out to elucidate the effect of harvesting time and low-temperature treatment on germination of corm in taro (Colocasia esculenta Schott). Corms of cvs. Eguimo, Wase-Hasuba, Akame, Takenokoimo and Malaysia No. 1 were harvested on 21 September and 23 November. They were planted in a growth chamber at 25°C just after harvesting. In cvs. Eguimo and Wase-Hasuba, the germination rate of corms harvested on 21 September was much lower than that of those harvested on 23 November. In cv. Akame, the germination rate of corms harvested on 21 September was slightly lower than that of those harvested on 23 November. In cvs. Takenokoimo and Malaysia No. 1, corms germinated rapidly irrespective of harvesting time. Corms of cv. Eguimo were harvested on 3 October and stored at 3, 10 or 25°C for 0-60 days. The germination rate was low in corms planted just after harvesting or after storage at 25°C for 60 days. Low-temperature treatment at 3°C for 15 days or at 10°C for more than 30 days strongly promoted germination. Low-temperature treatment also promoted germination of corms in cvs. Yatsugashira, Ohnoimo and Ishikawa-wase. Based on these findings, it was deduced that taro corm remains dormant from late September to early October, that the depth of dormancy varies with variety, and that dormancy is broken with low-temperature treatment at 3°C for 15 days or at 10°C for 30 days.
