2018 ASHS Annual Conference

The pawpaw (Asimina triloba) is a tree fruit indigenous to eastern North America, with small-scale commercial production in the US and worldwide on the rise. Over 50 pawpaw cultivars are available in the nursery trade, but many older cultivars have small fruit, low yields, and inferior flavor. Seedlings and controlled crosses at the National Clonal Germplasm Repository for Asimina spp. located at Kentucky State University (KSU) have been evaluated for yield, fruit size, and flavor; and several superior selections have been identified for evaluation and potential future cultivar release. To determine the performance of these selections at different locations, pawpaw variety trials including commercially available cultivars (‘Sunflower’ at all sites; KSU-Atwood^TM and KSU-Benson^TM at the Urbana, OH site) and five advanced selections identified in the KSU Repository Collection (G6-120, G9-109, G9-111, Hi4-1, and H3-120) were established in plantings at three grower cooperator sites, in central Ohio (Urbana, OH; USDA Plant Hardiness Zone 5b), southern Ohio (Aberdeen, OH; USDA PHZ 6a), and southern Kentucky (Bowling Green, KY; USDA PHZ 6b). Tree survival, trunk diameters, and flowering and yield data were collected at all sites. Trees began to fruit in 2015. Hi4-1, Sunflower and KSU-Atwood^TM were the most precocious-fruiting selections in the trials. Survival and vigor were greatest in selections Hi4-1, H3-120, and G9-111. Survival was slightly higher at the central Ohio site, likely due to better soil type than the other two sites, both of which had rocky soils. Number of fruit did not significantly vary among cultivars or location, possibly because they are in early production; differences may be seen once the trees reach full mature production. However, there was a trend for Sunflower, G6-120, Hi4-1, and G9-111 to have the most fruit per tree. Fruit weight varied significantly among selections, with the selections H3-120 and Hi4-1 and cultivars KSU-Atwood^TM and KSU-Benson^TM having the largest fruit, while G6-120 had the smallest fruit; G5-23, G9-109, G9-111 and Sunflower were intermediate in fruit size. Based on data from these trials and an earlier KSU trial, Hi4-1 will likely be named and released in fall 2018, and other selections will continue to be evaluated for potential commercial release.