Comparisons of Fruit Set and Quality between Seeded and Parthenocarpic Kaki Fruits cv. Fuyu in Relation to the Location of the Fruiting Shoot

Abstract

Fruit set, growth, and quality of seeded and parthenocarpic fruit of kaki cv. Fuyu were investigated. The objectives were: a) to compare the effect of pollination of flowers, borne on apical (terminal) and two lateral shoots, on non-pollinated (prevented pollination) flowers on adjacent shoots, and b) to determine the feasibility of producing a seedless 'Fuyu' crop under ordinary orchard conditions.
1. The set of parthenocarpic fruit from a basal (lower) lateral shoot was slightly lower and their size significantly smaller than was that of seeded fruit on adjacent shoots through the fruit growth Stage II.
2. The parthenocarpic fruit from the apical and two lateral shoots was significantly larger than the seeded fruit on basal lateral shoot which originated from one-yr-old wood on which apical and upper lateral shoot flowers were also pollinated.
3. These results suggest that a competition exists for assimilates between seeded and parthenocarpic fruit on different shoots arising from the same one-yr-old wood. The intensity of this competition among the fruit probably begins at the latter half of the fruit growth Stage I.
4. The set and weight of parthenocarpic fruit on a main branch were excellent at harvest and equivalent to the seeded fruit on the same tree.
5. Under ordinary orchard conditions, if all flowers on a tree were prevented from pollinating, fruit set was better and their weight and soluble solids contents were as good as those of seeded fruit derived from flowers on a separate hand-pollinated tree. The parthe nocarpic fruit was slightly flatter than the seeded ones.
We concluded that it might be possible to produce seedless 'Fuyu' fruit of excellent quality under ordinary orchard conditions, if all flowers of a tree were prevented from pollinating.