Passiflora ligularis

Passiflora ligularis, the sweet granadilla, grenadia, or sugarfruit, is a plant species in the passionflower genus Passiflora, family Passifloraceae.

Passiflora ligularis is an evergreen climbing shrub, producing stems of up to 5 m long. The stems scramble over the ground or clamber into the surrounding vegetation, attaching themselves by means of coiling tendrils. The leaves are ovate 8 - 22 cm long and 6 - 17 cm wide. The colour of the upper side is dark green and the underside green greyish. Younger leaves vary and can have a slight violet tone. The plant has shallow roots. The flower is 6 - 12 cm in diameter with acute sepals, a green outside and a white inside. The petals are 3 cm long and 1 cm wide, and they are white or white with a slightly pink or violet colouring. It needs to be pollinated, which is usually done by bumblebees, honey bees and large wasps. However, strong winds can interfere with the pollination of the flower as well as cause branch breakage, dehydration and scarring on the fruits. The flower only flowers for a day and the pollen may not be viable in the early morning or late afternoon. The plant does not seem to be photoperiodic as it is able to flower around the whole year. However, if the daily average of sunlight is less than 8 hours the fruits can become a brownish colour. The flowers have an aromatic, sweet and musky smell.

The fruit is initially green and becomes a yellowish orange with small white dots when ripe. It has a round shape with a tip ending in the stem. The fruit is between 6.5 - 8 cm long and 5.1 - 7 cm in diameter. The outer shell is hard and slippery and has soft padding on the interior to protect the seeds. There can be 250 - 300 seeds per fruit. These seeds are hard and black, surrounded by a gelatinous sphere of translucent pulp. The pulp is the edible part of the fruit and has a soft sweet taste. It is very aromatic and contains vitamins A, C, and K, phosphorus, iron, and calcium.

Passiflora ligularis thrives in well-drained soils, such as loamy or clayey soil amended with peat and sand to improve aeration and prevent waterlogging. It adapts well to both medium-textured (loam) and heavier soils (clay) but shows a preference for lighter, well-structured soils that support better flowering and fruiting. While the plant can grow in low-fertility soils, it performs best in those rich in organic matter, and amending the soil with organic compost or well-rotted manure is recommended to improve fertility. The soil should have a slightly acidic to neutral pH, ideally between 6 and 7, as excessively acidic or alkaline soil can hinder nutrient uptake. Further, Passiflora ligularis can grow in hilly or mountainous areas with slopes of up to 75%.

Passiflora ligularis grows optimally in warm, temperate climates with temperatures ranging from 15°C to 25°C, as cold conditions can hinder its development and frost can damage leaves and fruit. The species favors humid environments with annual rainfall between 1000 and 2000 mm, supporting root growth and fruit development. Sunlight is critical for its growth, as abundant light promotes photosynthesis and fruit sweetness.

The seedbed for Passiflora ligularis should be well-drained and nutrient-rich, prepared with loose, finely tilled soil to enhance root development. Seeds should be sown at a shallow depth of 1-2 cm and adequately spaced to prevent overcrowding. Consistent soil moisture is important, although waterlogging should be avoided. The ideal germination temperature ranges from 20°C to 30°C.

Balanced N-P-K (nitrogen-phosphorus-potassium) fertilizers should be applied every 4-6 weeks during the growing season, adjusted based on soil tests and plant needs. As a vine, Passiflora ligularis benefits from support structures like trellises, which improve air circulation and exposure to sunlight. Regular pruning removes dead or diseased foliage, focusing the plant's energy on fruit production and reducing disease risk.

· Germination: Seeds germinate within 15 days under ideal conditions, influenced by the fruit's maturity and fermentation time.