Field Establishment and Vigor of Kentucky State University Pawpaw Advanced Selections

Pawpaw (Asimina triloba), a tree fruit native to the Eastern U.S., is in small-scale commercial production with its popularity on the rise. New commercially available pawpaw cultivars are needed to increase the diversity and quality of pawpaw selections available to the public. However, field establishment of pawpaw orchards can be challenging due to drought and weed pressure. Seedlings contained in the Kentucky State University (KSU) National Clonal Germplasm Repository collection, established in 1995, were evaluated for fruit quality, yield, and size, and seven promising advanced selections were chosen for further trial and evaluation. In June 2011, a pawpaw variety trial including three commercially available cultivars (KSU-Atwood, Mango, and Sunflower) and seven advanced selections (G4-25, G5-23, G6-120, G9-109, G9-111, Hi4-1, and Hy3-120) was established at the KSU Research and Demonstration Farm in Frankfort, KY. The trial was planted in a randomized complete block design, with four blocks and two replicate trees per block, for a total of 80 trees. In February 2013, trees were evaluated for survival and trunk diameters were measured to determine early vigor. Overall survival in the variety trial among all cultivars and advanced selections after two growing seasons was 65%. Survival varied significantly by cultivar, with 100% of the KSU-Atwood trees surviving, and only 25% of selection G9-109 and 37.5% of selection G4-25 trees surviving, with the remainder of the cultivars and advanced selections displaying 50-87.5% survival. Diameters of the surviving trees did not vary by cultivar and means ranged from 9.7-17.1 mm. Early results indicate that advanced selections Hy3-120, Hi4-1, G6-120, and G9-111 have good field survival (over 75% of trees surviving), and have shown higher than average vigor when compared to existing pawpaw cultivars in the trial, with the exception of KSU-Atwood.