Kirk W. Pomper,1 Desmond R. Layne,2 R. Neal Peterson,3 and Dwight Wolfe4
ADDITIONAL INDEX WORDS. Asimina triloba, kentucky banana
SUMMARY. Beginning in 1993, 12 institutions and individuals and The PawPaw Foundation (PPF) embarked on a joint venture to evaluate commercially-available, named pawpaw (Asimina triloba) varieties and PPF's advanced selections within and outside of the pawpaw's native range. Each Pawpaw Regional Variety Trial (PRVT) planting, consists of about 300 trees, with five to eight replications (blocks) of 28 grafted scion varieties per block in a randomized complete block design (10 named varieties and 18 clones selected in the PPF orchards at the University of Maryland Experiment Stations at Queenstown and Keedysville, Md.). Variables being examined in the trial include climatic effect, culture, pests, growth, flowering, yield, and fruit characteristics. In 1995, PRVT plantings were established in Kentucky (Princeton, Ky.), Louisiana, North Carolina, Oregon, and South Carolina. In 1998, a second planting was established in Kentucky (Frankfort, Ky.). In 1999, PRVT plantings were established in Indiana, Iowa, Michigan, Maryland, Nebraska, New York, and Ohio. In the Frankfort planting, 95% of the trees have survived. Based on height and trunk diameter measurements taken from 1998 to 2001, most selections displayed good vigor. The variety PA-Golden had the best early fruit production as evidenced by the fact that five of eight trees had fruit in 2001. In the Princeton, planting, only 54% of the trees have survived. The selections 'Sunflower', 'PA-Golden', 'NC-1', 'Wilson', 1-23, 8-20, and 9-58 showed the best fruit production and survival rates (>63%) in 2001. Based on limited data collected so far in the Kentucky trials, 'PA-Golden' and 'Sunflower' have performed well in the two locations and other varieties and PPF selections show promise.
The pawpaw tree produces the largest edible fruit native to the United States (Darrow, 1975; Layne, 1996). Pawpaws are hardy to USDA growing zone 5 [−26.1 °C (−15 °F)] and grow wild in the mesic hardwood forests of 26 states in the eastern United States, ranging from northern Florida to southern Ontario (Canada) and as far west as eastern Nebraska (Kral 1960). In the wild, pawpaw trees grow 5 to 10 m (16.4 to 32.8 ft) tall, and are usually found in the forest understory in the deep, rich fertile soils of river-bottom lands (Lagrange and Tramer, 1985; Sargent, 1890). In sunny locations, trees typically assume a more compact pyramidal growth habit, with a straight trunk and long, drooping leaves. Dark maroon blossoms occur singly on the previous year’s wood, emerging before leaves in midspring. Flowers have a globular androecium and a gynoecium usually composed of three to seven carpels or three to seven-fruited clusters (Kral, 1960); up to nine-fruited clusters have been noted in the Kentucky State University (KSU) orchards (unpublished).
This research was supported by U.S. Dept. of Agriculture, Cooperative State Research, Education, and Extension Service Agreement no. KYX-10-97-28P with Kentucky State University. The technical assistance of S. Jones and E. Reed is also gratefully acknowledged by the authors. We wish to thank G. Brown for his assistance in propagating trees and establishing the planting in Princeton, Ky.
1Principal investigator of horticulture and curator, USDA National Clonal Germplasm Repository for Asimina species., Atwood Research Facility, Kentucky State University, Frankfort, KY 40601-2355. To whom reprint requests should be addressed.
2Associate professor of pomology and extension fruit specialist, Dept. of Horticulture, Box 340375, Clemson Univ., Clemson, SC 29634-0375.
3Peterson Pawpaws, P.O. Box 1011, Harpers Ferry, WV 25425.
4Horticulture research specialist, Department of Horticulture, University of Kentucky, Research & Education Center, P.O. Box 469, 205 Hopkinsville Street, Princeton, KY 42445.