Description
Pione is a black table grape from Shizuoka prefecture in Japan, bred by the private breeder Hideo Ikawa from Kyoho and a tetraploid muscat that DNA markers identify as Muscat Cannon Hall. Like Kyoho it is a tetraploid with a foxy, labrusca-type aroma. The vine sets fruit poorly unless it is managed carefully, and the berries can be made seedless with a gibberellin treatment.
Characteristics
Black table grape; tetraploid Kyoho × tetraploid Muscat Cannon Hall; foxy (labrusca-type) aroma; naturally seeded, can be made seedless with gibberellin; hermaphrodite flowers but a high share of abnormal ovules; flower shatter on vigorous shoots; grown under rain shelters and in greenhouses in Shizuoka
Growing Tips
Pione's weak point is fruit set. Japanese research links shatter to vigorous shoots and found more abnormal ovules on spur-pruned vines than on cane-pruned ones, so keep growth moderate and consider cane pruning. A gibberellin dip at full bloom gives over 90 percent seedless berries. In rainy Shizuoka it is grown in greenhouses or under rain shelters.