Combining apetalous parthenocarpy with columnar growth habit in apple

Summary

‘Wijcik’, a sport of ‘McIntosh’ with columnar growth habit, was crossed with ‘Wellington Bloomless’, which has apetalous flowers and bears parthenocarpic seedless fruit if not pollinated. The seedlings segregated for columnar versus normal habit but all had normal flowers and fruit. Four columnar seedlings were crossed with ‘Spencer Seedless’, another apetalous cultivar, and the resulting seedlings segregated not only for plant habit but also for apetalous versus normal flowers, approximately 1 : 1. Thus apetaly is controlled by a recessive gene, for which the symbolape is proposed. Apetalous columnar apples may be useful for planting in very high density orchards, cropping without pollination and thus not dependent on bees, pollinator varieties and warm weather at flowering time; moreover, being seedless they may avoid biennial bearing tendencies that are attributable to developing seeds inhibiting fruit bud formation.