Passion fruit farming

Propagation and planting

Passion fruit is propagated from seed, although cuttings and grafting are used. Seeds are rubbed clean of pulp and dried in the shade. Germination takes 2-4 weeks. Fresh seeds are much easier to germinate than seeds older than one or two months. Older seeds are soaked for at least one day to improve germination. Seedlings are often raised in polythene bags, 15 cm wide and 25 cm deep. Three seeds per bag are sown at a depth of 1 cm and thinned to leave one after two months. Cuttings are set in coarse sand and later transplanted into bags or a nursery bed. The seedlings gro slowly and require 3-4 months to reach the transplanting height of 15-25 cm.

Seedlings are hardened off by leaving them in an open, shaded area for a day or two.

Grafting is often used to control diseases. Yellow passion fruit is used as resistant rootstock although other Passiflora species, in particular P. caerulea L., show much greater resistance to Phytophthora root rot and Fusarium collar rot. Moreover, P. caerulea is tolerant of root-knot nematodes and to exposure to -1.5°C; it can be propagated from leaf and stem cuttings and is compatible with P. edulis. Wedge and whip grafts on seedling rootstocks - sometimes on rooted cuttings - are used.

Land preparation

Deep ploughing and harrowing is necessary to remove hard pans in the soil. Passion fruit has a deep root system; therefore proper land cultivation is necessary.

Commercial plantations adopt a row spacing of 1.2-1.8 m and a within-row spacing of

3 m. This gives around 1900-2700 plants/ha. Planting holes of 45 x 45 x 45 cm should be filled with topsoil mixed with up to 10kg of compost or manure. Transplanting is done at the start of the rainy season.

At planting the soil around the plants should be firmed down to establish good root/soil contact. In order to avoid fungal infection the grafting spot should not have any contact with the soil during and after planting. The seedling should then be irrigated to ensure quick rooting and establishment of the plant.

Crop establishment

Within 5-7 weeks after transplanting, each plant will have up to four healthy laterals.

From then on the vine grows very rapidly; the first flowers are produced 5-7 months after transplanting when the vine can be 10-15 m long. Light is the essential factor for flowering and in passion fruit this is particularly true for floral development and fruit set. That is why training and pruning are important to ensure adequate exposure of the shoots. Depending on the climate there may be one to three harvest peaks (purple passion fruit) or a single, often very long harvest season (more common with the yellow passion fruit).

The crop is established based on its crop management requirements. These include proper spacing fertilizer/manure application etc. This ensures that you avoid future activities like gapping, thinning e.t.c. which are labour intensive.

Crop management

Early growth of passion fruit is slow and regular weeding is essential. Care should be taken when weeding in order to avoid any injury to the plant. Mulching along the rows or around the base of the plants greatly facilitates weed control and protects the roots. A single wire trellis has been found to be as good. A 14-gauge galvanized wire is tightly stretched along the tops of hardwood posts 15 cm in diameter and 3 m long, dug in to a depth of 0.6 m; these posts are spaced 8 m apart. The trellis should be erected when the field is planted so that the main shoot and one vigorous lateral can be tied to the wire with a string. If laterals do not emerge in time, they can be forced to leaf out by pinching off the shoot tip. When the vines reach the wire they are trained in opposite directions along it. All laterals below the wire are pruned off.

Laterals emerging along the wire are allowed to hang down freely; they are the secondary shoots branching into tertiary shoots. Secondary and higher-order shoots are the fruiting wood, which has to be thinned and rejuvenated by pruning.

Regular fertilization is necessary for optimum yields. Frequent sprays with compost tea or similar organic foliar feed should be applied starting from 1 month after planting and at least every 3 months after that. Mixing EM or BM with foliar sprays may prevent fungus attacks.

1. Pruning

Old unproductive shoots and dead wood must be removed. Also secondary shoots reaching the ground must be cut off about 5 cm above the ground. The laterals which bear fruit should be left to hang down freely from the wire and the entangling tendrils removed to allow free air and light penetration and reduce incidences of disease and pest epidemics. Disinfect all equipment used for pruning regularly to avoid spread of viral diseases.

2. Intercropping

A wide range of vegetables and other crops are intercropped with passion fruit.

Intercropping with annuals is recommended; especially vegetables like beans, cabbages and tomatoes are agronomically suitable. Other recommended crops include potatoes, beetroots, Swiss chard, carrots, spinach, eggplants, peppers and onions.

However, cucurbits (cucumbers, pumpkin, and squashes) are not recommended due to the woodiness and fruit flies. Other crops that are not intercropped with passion fruits are maize, cowpea, sorghum, okra, sweet potatoes and other creepers. Intercropping help in erosion control particularly when fed with good compost.

3. Rotation

To avoid build up of soil borne diseases strict crop rotation is practiced. Passion fruits should not be grown for more than 4-5 years on the same plot.

Crop harvesting

Fruit drops to the ground when fully mature. It is collected every second day; at this stage it looks shriveled and unattractive, but for processing fruits should be picked at this stage. For fresh fruit markets, fruit is picked after full color development when the whole fruit is purple or canary yellow, but before shriveling and drying set in.

Average yields are about 10 tons per hectare per year, but with good management and crop husbandry yields of more than 15-20 tons per hectare can be realized.

Post-harvest handling/treatment

This involves treatment of the produce to increase its vase life. It may be done during harvesting or shortly after the harvesting. Passion fruit has a long vase life making it an important crop in this area where storage facilities is limited. The passion fruits are stored in a dry place in the crates.