true. Rushville lies close to four Indiana towns where notable pawpaw activity took place early in the 20th century. These are as follows:
Although the source of ‘Overleese’ is unknowable, given the pronounced interest and activity in pawpaws found in central Indiana during the early 20th century, ‘Overleese’ may have descended from a previous selection.
In 1970, Milo Gibson identified and propagated a superior pawpaw from the extreme western edge of the pawpaw’s native range in southeastern Kansas (Fig. 2). Davis evaluated, propagated, publicized and named this variety ‘Sunflower’ (Davis, 1974). A second selection attributed to Gibson is ‘Mary Foos Johnson’, which was either selected from the wild in Kansas by Gibson, or was a seedling donated to the North Willamette Experiment Station, Aurora, Ore., by Mary Foos Johnson. As these two possibilities are not mutually exclusive, one may wonder if ‘Mary Foos Johnson’ is an offspring of ‘Sunflower’.
For 25 years Corwin Davis did much to popularize the pawpaw with his horticultural work and his participation in the NNGA (Fig. 2). He was active in searching the Michigan woods for superior trees, which resulted in his selecting ‘Davis’ (1959), ‘Taylor’ (1968) and ‘Taytwo’ (1968). Davis also assembled a large collection of named varieties at his home in Bellevue, Mich., and engaged in breeding. From his open-pollinated crosses came the varieties ‘Prolific’ in 1985 and the varieties ‘Convis’, ‘Lynn’s Favorite’, ‘Tollgate’ and ‘Lady D’ in 1993 and from a controlled cross (“Overleese”)
Fig. 3. Pawpaw cultivar development and major lines of descent, 1985 to 2000.
x ‘Davis’) the variety ‘IXL’ in 1976 [Layne, 1997; L. Sibley (Davis’s son-in-law), personal communication].
John Gordon, living in Amherst, N.Y., contributed a series of varieties whose ancestry can be traced to Zimmerman germplasm (Fig. 2). Gordon gathered seed from trees belonging to George L. Slate of Cornell University who in turn had gathered his seed from trees on Zimmerman's estate. Gordon named one variety 'SAA-Zimmerman' in 1985 and a series of others 'Pennsylvania Golden No.1', 'No.2', 'No.3' and 'No.4' in 1986. This series of varieties are noted for their early season of ripening. Three other varieties he introduced in that same year are seedlings of 'Overleese', a series called 'SAA-', 'SAB-', and 'SAC-Overleese'.
Doug Campbell, living in Niagra-on-the-Lake, Ont., Canada, at the northern edge of the pawpaw's range, introduced a superior selection named 'NC-1' in 1976 (Fig. 2). This variety originated as a seedling from a fruit of 'Davis' on Corwin Davis's property. The cluster had been allegedly hand-pollinated with 'Overleese' (J. Gordon, personal communication) although that belief was questionable because of the results from DNA studies at Clemson University and KSU (Huang et al., 2003; Pomper et al., 2003).
In summary, during the course of pawpaw variety development between 1950 and 1985 many varieties were selected from both wild and cultivated sources. Increased breeding produced many varieties from open-pollinated crosses, most notably by Davis. A few varieties originated as controlled crosses, namely ‘IXL.’ Evaluations were performed by Glaser, Davis, Gordon and Campbell (and probably others) although accounts of those evaluations were unpublished. The preservation of germplasm from this period was not a problem since varieties were widely disseminated, and most pawpaw collectors of this period are still living.
crosses, namely ‘IXL.’ Evaluations were performed by Glaser, Davis, Gordon and Campbell (and probably others) although accounts of those evaluations were unpublished. The preservation of germplasm from this period was not a problem since varieties were widely disseminated, and most pawpaw collectors of this period are still living.
1985 TO 2000: GERMPLASM RECOVERED, A NEW CONTEST, A GERMPLASM REPOSITORY, AND MORE BREEDING. The last decades of the 20th century saw an increase of activity in pawpaw domestication. In 1981, Neal Peterson began a large-scale breeding program to develop improved pawpaw varieties (Peterson, 1982, 1986) (Fig. 3). With the cooperation of the University of Maryland, he established evaluation orchards at their agricultural experiment stations at the Wye, Queenstown, Md., and at Keedysville, Md. All 1483 accessions were open-pollinated seedlings, with most coming from the plant material that survived in the collections of Blandy, Buckman, Hershey and Zimmerman. Secondary germplasm came from other minor collections of the period, certain wild stands, and seven named varieties.
By 1994, Peterson had selected 18 advanced numbered selections and these were included with 10 named varieties in a set of regional variety trials conducted at 12 universities (Pomper et al., 1999). Continued evaluation by Peterson—most especially his experience in harvesting and selling pawpaws at a farmers market in Washington, D.C., from 1999 to 2001—led him to identify three of his selections as superior: