Flowering and fruiting characteristics of eight pawpaw [Asimina triloba (L.) Dunal] selections in Kentucky

The North American pawpaw [Asimina triloba (L.) Dural] is in the initial stages of commercialization; however, little information has been published concerning flowering and ripening periods of commercially available cultivars. Cultivars with late flowering or extended bloom period could be useful to growers for avoiding crop losses to late spring frosts. The objectives of this study were to determine if mature trees of commercially available pawpaw cultivars display: 1) concentrated bloom periods, 2) late flowering characteristics, 3) high fruit set, and 4) concentrated fruit ripening characteristics that were related to concentrated bloom periods. An orchard was planted in the spring of 1998 in a randomized block experimental design with 8 replicates. In 2004 to 2006, the cultivars 'Middletown', 'Overleese', 'PA-Golden', 'Sunflower','Wells', 'Wilson', 'NC-1'and the advanced selection 2-54 were evaluated for flower number per tree, density, peak, and duration, as well as trunk cross-sectional area, fruit set, days between flower and harvest peak, duration of harvest, fruit weight, yield, and number of fruit per cluster. An extended flowering period or larger flower number did not improve fruit set. Mature trees of commercially available pawpaw cultivars did not display concentrated bloom periods or ripening periods; however, 'Wells' and 'Middletown' did have late flowering peaks (maximum number of flowers) that could allow a partial crop if early spring frosts destroy flowers around or at the flowering peak. However, the average fruit size of 'Wells' and 'Middletown' is small and undesirable for commercial production.