Mechanism of Staggered Multiple Seedling Production from Amorphophallus bulbifer and Amorphophallus muelleri and its Application to Cultivation in Southeast Asia

Abstract

In Amorphophallus bulbifer and Amorphophallus muelleri, five seedlings develop sequentially in a year when seeds are sown, and two seedlings develop when bulbils are used as planting materials. This growth mode of release of multiple seedlings contrasts with the traditional growth mode of commonly grown konjak species, i.e. production of one corm by a single seedling. In the present study, the propagation rate and the bulking rate were compared between the relay seedling release mode and one seedling release mode. The propagation coefficients were 1, 10 and 330 when seed corms, bulbils and seeds were used as planting materials, respectively. The bulking rates were 6,000 and 100 when seeds and bulbils were planted, whereas 4-6 when seedlings were raised directly from a corm. Cultivation under greenhouse conditions enhanced the germination and prevented the onset of dormancy. As a result, the cultivation period was prolonged from 6 to 9-10 months. The prolongation of the growth period and the multiple seedling release mode may enable to produce a big corm within a year; two years earlier under greenhouse conditions than under field conditions. It is likely that the yield potential of cultivated species of konjak which is presently low could be enhanced if seedlings derived from seeds were grown in a greenhouse.