2019 ASHS Annual Conference

The North American pawpaw [Asimina triloba (L.) Dunal] is a native tree-fruit that is in the early stages of commercial production across the southeastern United States with fresh market appeal for farmers markets, community supported agriculture, and organic markets, as well as processing potential for frozen pulp production. Although there are approximately 50 pawpaw cultivars available, many pawpaw varieties tend to be low yielding and have small fruit size of less than 120 grams. Pawpaw varieties with fruit weighing over 120 g per fruit are considered to have a large enough fruit size for commercial sale and processing. New high yielding cultivars with excellent fruit quality would further assist in the development of the pawpaw industry. Kentucky State University has already released three pawpaw cultivars, KSU-Atwood^TM in 2009, KSU-Benson^TM in 2016, and KSU-Chappell^TM in 2018. However, additional high quality cultivars are needed. In 2013 and 2014, crosses were made between ‘Sunflower’ x ‘Susquehanna’, ‘Susquehanna’ x ‘Sunflower’, Hi4-1 x ‘Sunflower’ ‘Sunflower’ x 7-90, and open pollinated seedlings of ‘Shenandoah’ and ‘Susquehanna’. Seeds were extracted from fruit produced from the crosses and seed was sown in soilless medium in the greenhouse. In 2017, all seedlings were then field planted, with 32 seedlings of ‘Sunflower’ x ‘Susquehanna’, 35 seedlings of ‘Susquehanna’ x ‘Sunflower’, 37 seedlings of Hi4-1 x ‘Sunflower’, 19 seedlings of ‘Sunflower’ x 7-90, 60 open pollinated seedlings of ‘Susquehanna’, and 14 open pollinated seedlings of Shenandoah. To evaluate establishment of the genotypes, survival of trees in the planting was evaluated in 2018. The survival rate was: 34% for seedlings of ‘Sunflower’ x ‘Susquehanna’, 31% for seedlings of ‘Susquehanna’ x ‘Sunflower’, 38% for seedlings of Hi4-1 x ‘Sunflower’, 73% seedlings of ‘Sunflower’ x 7-90, 53% for open pollinated seedlings of ‘Susquehanna’, and 71% for open pollinated seedlings of ‘Shenandoah’. For the 197 seedlings planted, the overall survival rate for the planting was 47%. Many trees that had died will be replaced with the same type seedling in 2019. For all selections, the time to bloom, fruit weight, yield, and disease susceptibility will be evaluated in the coming years.