Nutrient Level and Seed Number in ‘Magness’ Pears as Related to Fruitfulness

Abstract

The 'Magness' pear, introduced in 1960, is a vigorous tree with high resistance to fire blight ( Erwinia amylovora), and has excellent dessert quality. Several 'Magness' plantings have been establsihed in Maryland, but most have been late bearing and have cropped lightly. Bearing problems have also been reported by Janick (2). Caron (1) has reported that honey bee activity is low on 'Magness' trees as compared with other nearby cultivars. Although 'Magness' produces no pollen, it can be effectively cross-pollinated by pollen from a wide range of cultivars (5). In hand-pollination breeding work, van der Zwet et al. (5) have found seed count in 'Magness' to be similar to that in other cultivars. Fruiting was evidently the result of fertilization and not due to parthenocarpic set. However, Scott and Thompson (4) have reported some normal-sized seedless fruits in open-pollinated 'Magness', indicating that parthenocarpic fruit set van occur.