Melofon, the new crop derived from this breeding program is characterized by its' high yield and adaptability to a once-over harvest system. In this study, the yield potential of advanced melofon lines is compared to pickling cucumber cultivars in both small experimental and semi-commercial plots. The fruit yielding ability of 70 experimental melofon hybrids were determined in order to select parental lines with the best general and specific combining ability for concentrated fruit yield and quality.
Melofon lines produced more fruits per unit area than pickling cucumber cultivars. This difference was highly significant at BH (Table 1) and to a lesser extent at NY (Table 2). Melofon lines had more small fruits as compared to pickling cucumber cultivars and this difference was reflected in small fruit yields. At the BH site, the average small fruit yield in the five best lines was 1.9 fold higher in melofon than in pickling cucumber, whereas the commercial yield was only slightly different. As small pickles have a much higher cash value than larger fruits, this difference between melofon and pickling cucumber is important. It should be noted that the timing of harvest of both crops was based on studies conducted in cucumber (Wehner 1988) and the optimal timing for once-over harvest in melofon must still be determined. Fruit set uniformity expressed as yield concentration (Tables 1 and 2) was higher in melofon than in pickling cucumber. The vegetative growth in melofon plants (more side branches than pickling cucumber plants) was remarkable. Data indicate that a plant density study is necessary to determine optimum plant populations for maximizing performance. However, preliminary observations indicate that plant densities of melofon for optimum once-over harvest yield is lower than in pickling cucumber.
Yield (fruit number and weight) differences between melofons and pickling cucumbers were remarkable in the semi-commercial plots trial (Table 3). The melofon line D17-5-135-1-5 set about 10 fruits/plant simultaneously in both pickings. The fruits of this line are round and therefore another quality grading method must be developed for them. The melofon line P6a-3-133-80-5-1-1 have cylindrical short light green fruits and has potential for high concentrated yield (Table 1, 2, 3). In this trial, it had not been harvested at the optimum time. Harvest dates were selected to meet line D17-5-135-1-5 optima, therefore, the first harvest was early and the second late for line P6a-3-133-80-5-1-1. Line P20a-8-9 segregated for bitterness and is being subjected to further selection.
Melofon plants are vegetatively more vigorous than pickling cucumber and therefore must be grown at relatively low plant densities.
Round and oval fruit shape of some melofon lines (Fig. 1) will require new agrotechnic systems including the determination of optimal once-over harvest time and unique grading scales.
Selection within open pollinated and F, melofon germplasm could result in more uniform genotypes and improvement in yield concentration.
Commercial yield | Small fruit yield | |||||
Line/cultivar | fruits/m2 | g/m2 | fruits/m2 | g/m2 | Yield concentration (%) | Vegetative fresh wt (g/plant) |
Melofon | ||||||
D17-2-180-3-2-6 (2) | 37.1 | 1339 | 30.1 | 751 | 42 | 268 |
P6a-3-133-80-5-1-1 (9) | 36.0 | 1464 | 28.4 | 701 | 53 | 281 |
D17-6-140-1-1-2 (10) | 34.0 | 677 | 30.6 | 463 | 65 | 279 |
D17-5-135-1-7 (3-sib) | 31.7 | 1023 | 17.6 | 205 | 35 | 480 |
P6a-4-13-5-2-1-1-9 (5) | 22.6 | 1009 | 17.7 | 476 | 45 | 251 |
Mean | 32.3 | 1102 | 24.9 | 519 | 48 | 312 |
Pickling Cucumber | ||||||
XPH 1369 (US) | 18.7 | 1207 | 11.4 | 327 | 33 | 165 |
Pickmore (US) | 17.5 | 939 | 10.6 | 284 | 35 | 99 |
Shahal (Israel) | 16.4 | 980 | 8.0 | 251 | 32 | 91 |
Aurora (US) | 15.6 | 1132 | 7.5 | 292 | 28 | 173 |
Passion (Holland) | 13.9 | 656 | 9.5 | 237 | 47 | 119 |
Mean | 16.4 | 983 | 9.4 | 278 | 35 | 129 |
Variance analysis between speciesz | ** | NS | ** | ** | * | ** |
Commercial yield | Small fruit yield | |||||
Line/cultivar | fruits/m2 | g/m2 | fruits/m2 | g/m2 | Yield concentration (%) | Vegetative fresh wt (g/plant) |
Melofon | ||||||
P6a-3-133-80-5-1-1 (9) | 25.7 | 1420 | 19.2 | 431 | 33 | 231 |
D17-6-140-1-1-2 (10) | 24.2 | 697 | 19.1 | 321 | 50 | 238 |
D17-2-180-3-2-6 (2) | 23.1 | 1346 | 12.0 | 271 | 44 | 238 |
P6a-3-53-91-B-B-2-5 (4) | 19.6 | 1455 | 10.2 | 293 | 46 | 198 |
P6a-4-13-5-2-7-2-8 (8) | 16A | 1370 | 9.5 | 196 | 40 | 204 |
Mean | 21.8 | 1258 | 14.0 | 302 | 43 | 222 |
Pickling cucumber | ||||||
Shahal (Israel) | 21.9 | 1044 | 12.4 | 338 | 34 | 111 |
Aurora (US) | 16.0 | 1152 | 8.4 | 275 | 34 | 167 |
Tomara (Holland) | 16.0 | 1097 | 4.7 | 142 | 50 | 163 |
Passion (Holland) | 14.7 | 635 | 10.1 | 295 | 36 | 132 |
Pickmore (US) | 14.7 | 888 | 8.5 | 255 | 30 | 176 |
Mean | 16.7 | 963 | 8.8 | 261 | 37 | 150 |
Variance analysis between speciesz | * | * | ** | NS | * | * |
First harvest yield | Second harvest yield | |||||||
Commercial | Small fruits | Commercial | Small fruits | |||||
Line/cultivar | (No.) | (kg) | (No.) | (kg) | (No.) | (kg) | (No.) | (kg) |
D17-5-135-1-5- (3) (M) | 4259 | 168.0 | 1870 | 25.6 | 3538 | 112.9 | 2175 | 30.1 |
P6a-3-133-80-5-1-1 (9) (M) | 1930 | 99.7 | 1435 | 36.9 | 2095 | 183.7 | 731 | 26.2 |
P20a-8-9 (M) | 2504 | 65.3 | 1842 | 25.9 | | | | |
P22a-5-7 (M) | 685 | 72.7 | 327 | 14.5 | 687 | 77.4 | 267 | 12.0 |
Passion (C) | 148 | 5.3 | 135 | 3.8 | 1044 | 72.1 | 628 | 27.2 |
NK 2002 (C) | 105 | 8.0 | 52 | 1.4 | 509 | 49.7 | 207 | 7.0 |
Commercial yield | Small fruits yield (diam. <35 mm) | |||
Line/Hybrid | (fruits/m2) | (g/m2) | (fruits/m2) | (g/m2) |
3 | 46.2 | 1580 | 19.7 | 300 |
210 | 37.1 | 1505 | 26.5 | 605 |
10 | 32.0 | 1575 | 17.0 | 375 |
910 | 28.8 | 1815 | 17.2 | 605 |
23 | 27.8 | 1575 | 20.8 | 540 |
92 | 26.9 | 1700 | 16.5 | 505 |
21 | 25.6 | 1540 | 17.6 | 540 |
2 | 24.4 | 1350 | 14.8 | 435 |
43 | 23.4 | 1620 | 15.0 | 455 |
510 | 22.6 | 1775 | 13.5 | 560 |
13 | 22.4 | 1140 | 14.2 | 385 |
9 | 22.2 | 1175 | 16.5 | 470 |
83 | 22.0 | 1230 | 13.3 | 425 |
110 | 21.9 | 1045 | 16.3 | 475 |
Fig. l. Fruits of melofon: (left) concentrated set of round fruit in D17-5-135-1-5; (right) cylindrical fruit shape of P22a-5-7.