One selection, ‘Montanari 1216’ (now named ‘Prima 1216’), had displayed cold hardiness, self-compatibility, and very large fruit size; a patent is currently pending on that selection (Bellini and Montanari, 2000).
Our collaboration with Domenico Montanari began in the early 1990s and is still in progress, with a primary focus on the development of new pawpaw varieties and evaluation of commercially available varieties for suitability for Italian fruit-growing areas. Traits that will be selected for are high productivity, large fruit size, good organoleptic quality, improved fruit storability and resistance to post-harvest handling. Storage and handling represent significant obstacles to the development of a large-scale commercial production of pawpaws. Also, interesting genotypes having double aptitude in ornamental value and fruit production will be identified.
Parents used in the breeding program were chosen within the first seedling population on the basis of agronomic, biological and pomological characteristics. In 1992, seed was obtained from a number of open pollinated isolated genotypes, and more than 2,800 seedlings were produced. A separate, parallel study was conducted with a wider genetic pool, to study the distribution of the progenies in relation to their respective female parents. In this study, 20 parental genotypes were selected on the basis of pomological traits, such as fruit shape (round to oval), size, homogeneity of both fruit shape and size within the tree and flowering form. From this work a total number of 430 seedlings were obtained. A seedling orchard was established in autumn 1995, after plantlets had been transplanted twice in containers of increasing size. These 2-year-old seedlings were planted out at the experimental farm Monna Giovannella at the University of Florence, in a slightly sloping field of about 2 ha (4.9 acres) and have been left unpruned. The seedlings are still in the juvenile phase, and are currently being evaluated for tree growth habit and vigor. Upon fruiting, seedlings will be selected based on fruit characteristics, ripening season, storage quality, as well as for yield and year-to-year consistency. We expect these trials to provide valuable information and genetic material for future work in pawpaw genetic improvement at the University of Florence.
distribution of the progenies in relation to their respective female parents. In this study, 20 parental genotypes were selected on the basis of pomological traits, such as fruit shape (round to oval), size, homogeneity of both fruit shape and size within the tree and flowering form. From this work a total number of 430 seedlings were obtained. A seedling orchard was established in autumn 1995, after plantlets had been transplanted twice in containers of increasing size. These 2-year-old seedlings were planted out at the experimental farm Monna Giovannella at the University of Florence, in a slightly sloping field of about 2 ha (4.9 acres) and have been left unpruned. The seedlings are still in the juvenile phase, and are currently being evaluated for tree growth habit and vigor. Upon fruiting, seedlings will be selected based on fruit characteristics, ripening season, storage quality, as well as for yield and year-to-year consistency. We expect these trials to provide valuable information and genetic material for future work in pawpaw genetic improvement at the University of Florence.
An evaluation of 15 pawpaw varieties commercially available in Italy was performed to examine adaptability of these varieties to the Italian climate. An orchard was established in 1990 in an experimental orchard located at Faenza, Italy with planting distances of 4.5 × 2 m (14.76 × 6.6 ft). Three replicate trees were planted for each variety. The pawpaw accessions included 14 varieties of American origin ('Sunflower', 'Overleese', 'Davis', 'Prolific', 'Sweet Alice', 'Maryfoos Johnson's', 'Mango', 'Taytwo', 'Taylor', 'Rebecca's Gold', 'NC1', 'Ithaca', 'Wells' and 'Wilson') and one of Italian origin ('Prima 1216'). Vegetative, reproductive and pomological characteristics were evaluated during the 2000 and 2001 seasons. Traits recorded for the vegetative characterization of trees included height and volumetric index of trees. Reproductive records included flowering time, ripening time, fruit weight, fruit soluble solids content, and finally tree yield. Data were analyzed by analysis of variance and means separation was performed by Duncan's multiple range test.
2 m (14.76 × 6.6 ft). Three replicate trees were planted for each variety. The pawpaw accessions included 14 varieties of American origin ('Sunflower', 'Overleese', 'Davis', 'Prolific', 'Sweet Alice', 'Maryfoos Johnson's', 'Mango', 'Taytwo', 'Taylor', 'Rebecca's Gold', 'NC1', 'Ithaca', 'Wells' and 'Wilson') and one of Italian origin ('Prima 1216'). Vegetative, reproductive and pomological characteristics were evaluated during the 2000 and 2001 seasons. Traits recorded for the vegetative characterization of trees included height and volumetric index of trees. Reproductive records included flowering time, ripening time, fruit weight, fruit soluble solids content, and finally tree yield. Data were analyzed by analysis of variance and means separation was performed by Duncan's multiple range test.
Analysis of variance showed a high variability among the varieties for many of the characters examined. There were significant differences among varieties in tree height and tree volumetric growth, with the variety Ithaca having the greatest height measurements both in 2000 and 2001 (Tables 1 and 2). In terms of flowering, there were significant differences among varieties in bloom time, with the varieties ‘Overleese’, ‘Ithaca’, ‘Mango’, and ‘Sunflower’ having the earliest bloom period in 2000 and 2001. The varieties Prima 1216, ‘Sunflower’ and ‘Davis’ bore the largest fruit [average weight of 202, 216, and 246 g (7.1, 7.6, and 8.7 oz), respectively] in both
Table 1. Vegetative and reproductive characteristics of 15 pawpaw varieties evaluated in 2000 in Faenza, Italy.
| Variety | Tree ht (cm)z | Tree volumetric indexy | Flowering time (d)x | Ripening time (d)y | Fruit wt (g)w | Soluble solids (%) | Tree yield (kg) |
|---|---|---|---|---|---|---|---|
| Davis | 290.0 bc | 1.15 b | 110 bc | 248 bcd | 216.3 a | 21.6 cef | 3.96 cde |
| Ithaca | 440.0 a | 1.60 ab | 106 cd | 252 ab | 123.9 de | 24.2 abc | 10.08 b |
| Mango | 415.5 ab | 1.78 ab | 106 cd | 246 cde | 196.1 abc | 24.8 ab | 10.73 b |
| Maryfoos Johnson | 258.6 c | 1.83 ab | 110 bc | 253 ab | 198.0 ab | 22.3 bcd | 2.24 de |
| NC-1 | 385.0 ab | 1.55 ab | 112 b | 251 abc | 164.6 abcd | 24.9 ab | 7.54 bc |
| Overleese | 360.0 abc | 1.39 ab | 104 d | 242 e | 138.3 bcd | 20.7 de | 4.35 cde |
| Prima 1216 | 382.0 ab | 1.41 ab | 110 bc | 250 abc | 209.5 a | 18.9 e | 15.70 a |
| Prolific | 310.0 bc | 1.77 ab | 112 b | 255 a | 113.5 de | 24.9 ab | 11.22 b |
| Rebecca's Gold | 330.5 abc | 1.20 b | 116 a | 246 cde | 64.9 e | 21.4 cde | 2.46 de |
| Sunflower | 320.0 bc | 1.18 b | 106 cd | 250 abc | 152.0 abcd | 20.6 de | 6.59 bcd |
| Sweet Alice | 250.0 c | 1.36 ab | 108 bcd | 253 ab | 173.9 abcd | 21.2 cde | 1.71 e |
| Taylor | 383.0 ab | 1.74 ab | 111 b | 252 ab | 106.2 de | 22.0 bcde | 3.96 cde |
| Taytwo | 380.0 ab | 1.56 ab | 116 a | 244 de | 127.2 cde | 26.5 a | 0.81 e |
| Wells | 257.0 c | 1.97 a | 109 bc | --- | --- | --- | --- |
| Wilson | 370.0 abcd | 1.51 ab | 111 b | 246 cde | 102.7 de | 19.9 de | 7.46 b |
| Pa | 0.0000 | 0.0070 | 0.0000 | 0.0002 | 0.0000 | 0.0000 | 0.0000 |
zBased on three replicate trees for each variety; trees were planted in 1990; 1.0 cm = 0.39 inches; 1.00 kg = 2.205 lb; 1 g = 0.035 oz.
Tree volumetric index was calculated by 2 H / longitudinal D + transversal D; where H = maximum crown height, longitudinally and transversally, D = longitudinal and transversal crown diameter measured at the maximum extent.
versal crown diameter measured at the maximum extent.
xFlowering time was evaluated at the peak of bloom judged by visual observation and expressed in days from 1 Jan.
vRipening time was expressed in days from 1 Jan.
wFruit weight based on the weights of 20 fruit.
1Data were analyzed by analysis of variance and means separation was performed by Duncan's multiple range test with a P < 0.05.