tions such as 3-21 and 9-47 did not exhibit as much growth as some of the more vigorous selections. There was a significant block effect on tree height for each variety (P > 0.038).
Fortrees that flowered during 1999 to 2001, the main flush of flowers appeared in mid-April; some varieties had a more prolonged flowering period that extended into May. In 1999, there were 33 fruit on 14 trees. Selections with the most fruit were ‘Middletown’ (4 fruit), ‘Mitchell’ (4 fruit), ‘Overleese’ (4 fruit), ‘Sunflower’ (6 fruit), and 10-35 (5 fruit). As a result of a hard freeze on 9 Apr. 2000, with temperatures dropping to -2 °C (28.4 °F), only 2 trees (10-35) produced a total of 8 fruit. In 2001, there were 74 fruit in the planting (Table 3). The variety PA-Golden had the best early fruit production as evidenced by the fact that 5 of 8 trees had fruit.
PRINCETON PLANTING. In the Princeton, Ky., planting, trees had an overall survival rate of 54% (Table 4). The only selection with eight remaining replicate trees was 10-35; selections with the poorest survival rate were ‘Wells’, ‘Taylor’, 5-5 and ‘Middletown.’ In 2000, there were 528 fruit on 122 trees; selections with the greatest number of fruit (>30 fruit by selection) were: ‘Sunflower’, ‘Wilson’, 8-20, 8-58, and 11-13. In 2001, there were 652 total fruit on 122 trees; selections with the greatest number of fruit (>30 fruit by selection) were: ‘Middletown’, ‘NC-1’, ‘Sunflower’, ‘PA-Golden’, ‘Wilson’, 1-23, 8-20, and 9-58. Although tree diameter was not determined in the Princeton planting in 2001 before the growing season, trees were 3 years older, and thus larger than in the Frankfort planting. The average trunk diameter
in July 2001 was 47 ± 8 mm (1.9 ± 0.3 inch), based on a sampling of the trunk diameter for 50 trees. The average trunk diameter before growth started in the Frankfort planting was 26 ± 4 mm (1.0 ± 0.2 inch). Fruit fresh weight varied significantly among varieties (P < 0.001), with 1-7-1 showing the best overall fruit weight for both 2000 and 2001, and ‘Wilson’ with a trend toward the smallest fruit weight in both years (Table 4).
Pawpaw yields are notoriously low (Peterson 1991). Bartholomew (1962) reported obtaining 4 kg (8.8 lb) of fruit and Ourecky and Slate (1975) obtained 11.5 and 23 kg (25.35 and 50.7 lb) from superior pawpaw trees. For paw-paw trees in their seventh year (sixth leaf) in 2001 in Princeton, the best yields
Table 3. Summary of tree growth and fruit production in 2001 for the Kentucky State University Pawpaw Regional Variety Trial (PRVT) in Frankfort, Ky.
| Selectionz | Trunk diam (mm) | Increase in ht (m)y from 1999 to 2001 | Surviving trees (%) | Surviving trees with fruit (%) | Total fruit (no.)x |
|---|---|---|---|---|---|
| PA-Golden | 36.7 aw | 0.86 a | 100 | 63 | 14 |
| 10-35 | 33.3 ab | 0.76 abc | 100 | 25 | 7 |
| 8-20 | 30.7 abc | 0.60 abc | 100 | 13 | 1 |
| NC-1 | 30.3 abc | 0.42 abc | 100 | 0 | 0 |
| 1-7-2 | 29.6 abc | 0.59 abc | 100 | 0 | 0 |
| Wilson | 29.5 abc | 0.68 abc | 75 | 17 | 2 |
| 3-11 | 28.8 abc | 0.33 abc | 88 | 0 | 0 |
| Sunflower | 28.6 abc | 0.80 ab | 100 | 13 | 6 |
| 1-68 | 28.1 abc | 0.58 abc | 100 | 13 | 2 |
| 9-58 | 28.1 abc | 0.32 abc | 100 | 13 | 1 |
| 7-90 | 27.2 abcd | 0.39 abc | 100 | 0 | 0 |
| 1-23 | 27.1 abcd | 0.28 abc | 100 | 0 | 0 |
| Taylor | 27.0 abcd | 0.37 abc | 75 | 17 | 2 |
| 11-13 | 26.8 abcd | 0.86 a | 100 | 13 | 5 |
| 8-58 | 26.0 abcd | 0.23 bc | 100 | 25 | 8 |
| 9-47 | 25.4 bcd | 0.18 c | 100 | 25 | 4 |
| Mitchell | 25.0 bcd | 0.52 abc | 100 | 0 | 0 |
| 4-2 | 24.7 bcd | 0.49 abc | 100 | 13 | 2 |
| 1-7-1 | 23.7 bcd | 0.35 abc | 88 | 0 | 0 |
| Overleese | 23.6 bcd | 0.35 abc | 88 | 0 | 0 |
| 2-54 | 23.5 bcd | 0.23 abc | 100 | 0 | 0 |
| Wells | 23.4 bcd | 0.32 abc | 88 | 29 | 11 |
| 2-10 | 22.6 bcd | 0.55 abc | 75 | 0 | 0 |
| Taytwo | 22.0 bcd | 0.38 abc | 100 | 13 | 4 |
| Middletown | 21.5 cd | 0.49 abc | 100 | 25 | 2 |
| 11-5 | 20.5 cd | 0.35 abc | 100 | 0 | 0 |
| 3-21 | 19.3 cd | 0.16 c | 100 | 0 | 0 |
| 5-5 | 16.4 d | 0.32 abc | 88 | 14 | 3 |
| Avgv | 26.1 \pm 4.3 | 0.46 \pm 0.20 | 95 \pm 9 | 12 \pm 14 | 74u |
2Trees were planted in Mar. 1998; selections ranked in order of increasing diameter.
yIncrease in tree height from Apr. 1999 until Apr 2001; 1.00 m = 3.281 ft.
xTotal number of fruit on remaining trees on 4 July 2001.
wStudent-Newman-Keuls separation of means at P < 0.05.; 25.4 mm = 1.0 inch.
vAverage ± SE.
uSum.