The origin of Yellow Passionfruit is debated. The geographical source appears to be South American, like that of Purple Passionfruit. Some passionfruit authorities consider it to be a mutant form of the Purple Passionfruit (Passiflora edulis) as the botanical name implies. Others argue for a possible hybrid origin.
Yellow Passionfruit is grown largely for the pleasantly aromatic juice obtained from the fruit. The juice is not especially noteworthy nutritionally, but it is a good source of vitamins A, niacin, and riboflavin. Yellow Passionfruit is a vigorous tropical vine in lowland tropics with larger fruits than Purple Passionfruit. It is more root knot nematode resistant than Purple Passionfruit making it commonly the passionfruit of choice in the lowland tropics. However, Purple Passionfruit is less acid, richer in aroma and flavor, and has a higher juice proportion than the yellow form. Passionfruit juices blend well with citrus fruit juices and many other tropical fruit juices, like pineapple, producing flavorful juice mixtures.
In contrast with the subtropical Purple Passionfruit, the Yellow Passionfruit is tropical to near-tropical thriving from sea level to an elevation of 700 m (2,000 ft). Yellow Passionfruit normally is grown from recently collected seed. Passionfruits seeds lose viability rapidly. Plant seeds 1.5-2.5 cm (1/2-1 in) deep in shaded beds. Germination occurs normally in 10-20 days. Transfer 25 cm (10 in) tall seedlings to well-drained organic matter rich soil with full sun exposure (in very hot climates provide partial shade). Provide strong trellis support for vine and fruit growth. Flowers of Yellow Passionfruit are self-sterile. Allow vines from different plants to intertwine on the trellis to promote cross-pollination and fruit set. Flowers of Yellow Passionfruit are open from approximately noon until dark. Hand pollination (placing picked pollen-bearing flowers in direct contact with open pollen-receptive flowers of another plant) may be required if Carpenter bees or other passionfruit pollinators are unavailable. Carpenter bees are promoted by placing decaying logs as bee nesting sites in the fields near passion vines. Honeybees may pollinate passion flower blossoms but the larger solitary Carpenter bees (Xylocarpa spp.) are more successful pollinators. Though it grows well from cuttings, note that cuttings from one mother plant will not be able to pollinate each other.
Harvesting and Seed Production
In Florida, USA, Yellow Passionfruit flowers from spring until late fall, with a break in early summer, so that mature fruit appears at intervals from early summer into winter. In less seasonal climates flowering and fruiting are more continuous. Yellow Passionfruits turn from green to yellow quickly at maturity. Soon after color change the ripe fruits fall off the vines. Pick them from the vine after color change occurs or collect them daily from the ground. Fruits left on the ground spoil quickly from the activities of soil microorganisms.
Pests and Diseases
A large variety of plant pests attack Yellow Passionfruit vines, especially in the tropics. Passion vine mites can defoliate plants in the dry season in some Hawaiian and Australian regions. Stinkbugs suck juices from tender shoots. Leaf beetles and weevils chew foliage. Caterpillars nearly defoliated vines upon occasion at ECHO. Cutworms behead seedlings in nurseries. Scale insects attack vines and petioles causing vine dieback. Fruit fly damage to young fruit occurs in some regions. Unlike Purple Passionfruit, Yellow Passionfruit is root knot nematode resistant and less susceptible to fruit spot diseases.
Cooking and Nutrition
Clean, washed and dried fruits will store for 2-3 weeks in a cool 10o C (50o F), well-aerated place. Slightly shriveled fruit, a few days old, is sweetest.
Morton, J. 1987. Passionfruit. p. 320–328. In: Fruits of warm climates. Julia F. Morton, Miami, FL.