Abstract
Plant and fruit characteristics of the parents and progeny from the interspecific cross Cucumis melo L. (PI 140471) × C. metuliferus E. Mey. (PI 292190) are described. An electron microscope scan (EMS) indicated that F1 seed exhibited both the netting from C. metuliferus and the ridging from C. melo but pollen from both parents and the F1 appeared to be identical. The F1 plants had lobed leaves as in the staminate parent (C. metuliferus). Trichomes of the F1 were intermediate. The F1 consisted of light green fruit with raised dark green areas and dark green fruit. Thirteen plants with spiney fruit were found in the F2. Ribbing and netting of fruit and andromonoecious flower types occurred in F2 progeny but did not occur in either parent. Weight, flesh and rind thickness, length, and diameter of F1 and F2 fruit greatly exceeded those of either PI 140471 or C. metuliferus. Attempts to duplicate the original cross were unsuccessful due to embryo abortion except for one plant grown by embryo culture. Backcrosses of the F1 to C. metuliferus were unsuccessful in the greenhouse and field due to embryo abortion except for 1 plant produced by embryo culture.
Abstract
Progeny from a hybridization of C. melo L. (PI 140471), a feral Cucumis melo, with the nematode-resistant African horned cucumber (C. metuliferus E. Mey.) (PI 292190) were screened for resistance to Meloidogyne incognita acrita Chitwood. Although C. metuliferus exhibited resistance, no resistance was observed in PI 140471 nor in the F2 generation after inoculation with a larval suspension having 600 larvae/ml. However, when grown in contact with chopped galled roots, certain progeny appeared to be resistant. Evaluation of egg mass production revealed that the resistant plants produced significantly fewer eggs than susceptible plants.
Abstract
Preharvest application of (2-chloroethyl)phosphonic acid (ethephon) to muskmelon (Cucumis melo L., Reticulatus group) significantly reduced the soluble solids content and the sucrose concentration of fruits harvested at the full-slip stage. Texture and flavor ratings were also reduced. During 5 days at 20°C, the flesh of fruits from treated plants softened more rapidly and was more aromatic than the fruits from untreated plants.
Abstract
Higher yields, larger fruit size, and earlier maturity were achieved in muskmelons (Cucumis melo L.) by irrigating when soil moisture tensions at the 25-cm depth reached 50 and 75 kPa compared with tensions of 25 kPa. More fruits were culled in the wet treatment due to decay while the drier treatments produced more fruits with growth cracks. Melons from the drier treatments were higher in soluble solids. Irrigation did not affect the other storage and shipping quality factors measured. A prethinning irrigation caused restricted root development, vine growth, fruit size, and yield.
Abstract
The salt tolerance of cultivars of muskmelon (Cucumis melo, L.) was established under 2 levels of radiation in a glasshouse experiment. ‘Galia’ and ‘Top Mark’ muskmelon differed very little in salt tolerance at either radiation level. The maximum electrical conductivity of a saturated soil extract without yield reduction, the salt tolerance threshold, was 2.0 dS m−1. Beyond the threshold, yield was reduced at a rate of 14.3% per unit increase in soil salinity. Both cultivars were more salt-tolerant at the higher level of solar radiation.
Abstract
Pretransplanting nutritional conditioning (PNC) regimes were evaluated for their effects on improving tolerance to transplant shock and increasing early fruit production. Muskmelon seedlings (Cucumis melo var. reticulatus L. ‘Magnum 45’) were fertilized twice weekly with solutions containing N, P, and K to determine nutrient needs required to produce high-quality transplants. Seedling height, stem diameter, leaf area, shoot and root dry weights, leaf number, and shoot: root ratios of 27-day-old transplants increased as N rates increased from 10 to 250 mg liter−1. These growth variables also increased with P from 5 to 25 mg·liter−1 but decreased as P increased from 25 to 125 mgliter−1. Increasing K rates from 10 to 250 mg·liter−1 increased seedling height, stem diameter, and leaf area. Nine PNC regimes ranging from low to high N-P-K status were tested under field conditions to determine any long-term advantage. Generally, as PNC levels increased, transplant shock (percentage of necrotic leaves) increased as measured 12 days after transplanting. However, vining, female flowering, fruit set, and early yields increased as PNC levels increased. A high level of PNC (250N-125P-250K, mg·liter−1) conditioned transplants to overcome shock and to resume growth sooner and yield earlier than those at lower PNC levels.
Abstract
Resistance of muskmelon (Cucumis melo L.) to low levels of pickleworm (Diaphania nitidalis [Stoll]) was heritable whether expressed as percent damaged fruit or number of punctures per damaged fruit.
Abstract
‘Green Ice’ is a green-fleshed muskmelon (Cucumis melo L.) adapted to the climatic conditions prevalent in the southeastern United States and is well-suited for both commercial and home garden production. It is a high-yielding ‘Honey Ball’-type muskmelon that produces round to oval, pale gray-green, medium-sized fruit that turn cream-colored and slip from the vine at maturity. The thick light-green flesh has a pleasing aroma and sweet flavor and is high in vitamin C. The vigorous plants are resistant to race 3 of powdery mildew [Spaerotheca fuliginea (Schlect ex Fr.) Poll.] and tolerant to most pests and environmental stresses of the region.
Abstract
The concentration of fructose, glucose, sucrose, raffinose, and stachyose in the leaves, stem, and fruit of the muskmelon plant (Cucumis melo L.) was determined using paper and gas chromatography. Stachyose was the predominant sugar in the leaves but was absent in the developing fruit. Most of the 14C label in 14CO2-treated leaves was associated with stachyose, while the 14C label in the fruit was associated with fructose and glucose. The concentration of stachyose was highest in the leaves, intermediate in the stem, and lowest in the fruit.
Abstract
Feeding of pickle worm Diaphania nitidalis (Stoll), on muskmelon (Cucumis melo L.) differed, but more definitive laboratory testing under controlled condition is needed to determine if usable resistance mechanisms are involved. Few differences were detected in larval feeding on muskmelon seedlings with various characteristics. However, adult pickleworms laid fewer eggs on glabrous muskmelon and cucumber (Cucumis sativus L.) plants than on pubescent ones.