Noor Sugiharto Arifin, Hiroshi Okubo, Noriko Miho
Dormancy status in the bulbs of 12 shallot and 66 A. × wakegi accessions was investigated and a more time saving and practical method for dormancy breaking of the bulbs was studied. Dormancy of shallot is weaker than that of A. × wakegi. The average days to 50% sprouting of A. × wakegi accessions were not significant among Indonesian, Japanese and other countries' accessions, but the variation of them was more marked in Japanese than in Indonesian accessions. The bulbs of which the upper half or one third had been transversely cut just before planting sprouted earlier than intact control bulbs. The closer the cut was made to the growing point, the earlier was the sprouting. Those of which the half portion had been longitudinally cut also sprouted earlier than the intact control. This old and simple technique, to cut transversely upper one third or half of the bulbs, was suggested to be practically used in shallot and A. × wakegi production. Those of which the upper half had been transversely cut and the cut surface had been covered with plain lanolin also sprouted earlier than the intact control, suggesting that the removal of some inhibiting substances contained in the scales promoted sprouting.
Laboratory of Horticultural Science, Faculty of Agriculture, Kyushu University 46-01, Fukuoka 812-8581, Japan; Department of Plant Breeding, Faculty of Agriculture, Brawijaya University, Malang, Indonesia
