Neal Peterson and Harry Swartz germplasm collection (1981)

Screening of about 1500 accessions at the University of Maryland

Open pollinated seedlings from collections of Buckman, Zimmerman, Hershey, Allard, the Blandy Experimental Farm, Ray Schlaanstine, and some modern cultivars

Pawpaw Regional Variety Trial initiated in 1994 by R. Neal Peterson and Desmond Layne

10 cultivars and 18 PPF advanced selections