Passion fruits

Land Preparation: Passion Fruit

Once suitable site is located, it has to be prepared for proper support of the growing plant. The seedbed must be free from other competing plants and the soil in good form for the seeds or seedlings to get established.

If the land to be used for growing passion fruit is new land, it has to be cleared of all bushes and tree stumps. Land cultivation is done with soil erosion measures taken care of. Deep digging is necessary to remove hard pans in the soil. Passion fruit has a deep root system; therefore proper land cultivation is necessary.

The soil should be cultivated to a smooth and well leveled seedbed or nursery bed from which all debris has been removed. This allows the seed germinate easily and the seedling to be well established. The cultivation of the soil is meant to loosen the soil for easy penetration and retention of water, adequate air circulation and minimum resistance to root penetration and development.

Planting: Passion Fruit

1 Crop Propagation

The passion fruit  can be propagated by seeds, cuttings or by grafting.

1.1.  Propagation by seed

Fresh seeds should used because they germinate easier than seeds older than 2 months. If older seeds are used they should be soaked for at least one day to improve germination. Seeds will germinate in 2-4 weeks. The seedlings are generally raised in polythene bags 15 cm wide and 25 cm deep. Three seeds are put in one bag and thinned to one seedling after two months. The seedlings are ready for transplanting 3-4 months by then they are 15-25 cm in height. The plant is in flower 5-7 months after transplanting.

1. 2. Propagation by cuttings

Cuttings are set in coarse sand and later transplanted into bags or a nursery bed. The seedlings grow slowly and require 3-4 months to reach the transplanting height of 15-25 cm.

1. 3. Propagation by grafting

Grafting is often used to control diseases. Yellow passion fruit is used as resistant rootstock.

1.2. Transplanting

Commercial plantations adopt a within row spacing of 1.2-1.8 m and between rows 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 10 kg 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. The seedling should then be watered to ensure quick rooting and establishment of the plant.

For grafted propagation,  the grafting spot should not have any contact with the soil during and after planting in order to avoid fungal infection.

It is important to erect structures for the vines to climb on before planting so that as the vines grow they are trained to climb on these structures.

Crop management: Passion Fruit

1. Fertilizer/manure application

Passion fruits are good feeders and readily respond to nutrients applied to them. At the time of planting seedlings, 30 kg of manure is put in each hole and repeated every year. 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.

2. Weeding

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.

3. Mulching

Mulching helps in weed control as well as preservation of soil moisture. When the mulch decomposes, it adds to soil fertility and improves soil structures.

4.  Pruning

Pruning is an important activity in passion fruit husbandry for keeping the vines within bounds, making harvest easier and to keep the plants productive by maintaining vigorous growth. It is also important to prune the passion fruit for the following reasons:

• Pruning gives the crop a growing direction. Two healthy shoots are selected and the rest are cut off.
• Improves yields of the crop. Cutting off shoots that will produce other branches enhances rapid growth.
• Removes branches that are fruitless, damaged or diseased.
• Rejuvenates the plant. When pruned at a height of 30 cm when yields decline, it sprouts and produces new branches.

5. Trellising

Trellising is constructing support structures on which the vines climb by gripping on them using the tendrils. In the East Africa region, a single wire trellis has been found to be 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.

When the vines reach the wire they are trained in opposite directions along it. All laterals below the wire are pruned off.

Management of pests and diseases: Passion Fruit

1. Brown spot (Alternaria passiflorae)

The most important disease worldwide is brown spot on leaves, vines and fruits. Symptoms are brown spots, up to 10 mm diameter, on the leaves, often extending along the veins and drying out in the centre. On the stems, spots are up to 30 mm long, and when they occur at the leaf axils may kill the vine, resulting in dieback. On the fruit, the spots are light brown, round and sunken; they often merge, covering large areas, and produce red-brown spore masses.

Spores, produced on the leaf, stem and fruit, are dispersed by wind-blown rain. Warm, moist weather favours disease development.
Management:

• Yellow passion fruit and its hybrids are more tolerant of this disease.
• Field sanitation (collection and disposal of fallen diseased fruits, leaves and vines)
• Pruning vines to reduce density and thereby reducing humidity within the crop
• Timely sprays with copper based fungicides. During humid weather, when the vines are growing rapidly, reduce the intervals between spray applications to 2 or 3 weeks to ensure that new growth is adequately protected.

2. Septoria spot (Septoria passiflorae)

The disease attacks leaves, stems and fruits. Infected leaves fall readily leading to defoliation of vines. Similar spots may form on the stems albeit elongated. On fruits light-brown spots studded with minute black dots may be formed. The spots often join up to cover large areas of the fruit. Affected fruits ripen unevenly. Spores produced by black dots (fruiting bodies) are blown to adjacent vines during wet, windy weather thus further spreading the disease. The disease is spread by rain, dew and overhead irrigation. Warm moist weather favours disease development.

Management:

Disease management measures for brown spot disease (see above) are equally applicable for septoria spot.

3. Fusarium wilt (Fusarium oxysporum f.sp. passiflorae)

Symptoms consist of yellowing of leaves, the collar region of affected plant at soil level turns brownish and vertically cracks and vines wilt followed by a complete collapse of the plant. On dissection of infected stem, vascular tissues show brown discolouration.

Management:

• Affected parts should be removed and burned. Snap off the affected parts or remove the affected plant manually.
• Do not cut tissue and then use the knife on healthy plants.
• Keep the base of the plant clear of grass and weeds, which favour fungal growth.
• Grafting to wilt-resistant yellow passion fruit rootstocks is the most practical way of control.

4. Phytophthora blight (Phytophthora nicotianae var. parastica)

Affected leaves are water-soaked and light-brown in colour. They fall readily, leading to defoliation of the vines. Affected areas of the stem are first purple and later brown above the graft union. They may completely girdle the stem causing wilting and collapse of the vine.

Fruit symptoms comprise of large, water-soaked areas. Diseased fruits fall readily and in wet weather become covered with white, fungal growth.

Another strain (Phytophthora cinnamoni) causes root rot. Yellow and purple vines have different patterns of susceptibility. The yellow vine is susceptible to P. cinnamoni, and the purple vine is more susceptible to P. nicotianae. Both fungus strains attack both passion fruits and can cause root rot, wilt, damping off and leaf blight. Fungal spores are initially produced in wet soil beneath the vines and are splashed up to lower leaf canopy.
The disease is favoured by wet, windy weather.

Management:

• Good field sanitation
• Pruning and keeping a grass sward under the vines to minimize spore splashed up to the lower leaves.
• The application of copper-based fungicides every 2-3 months during the wet season reduces disease incidence in areas where the disease is likely to be serious. Lesions may be painted with a copper fungicide.

5. Passion fruit woodiness potyvirus (PWV)

Affected leaves show light and dark green mosaic pattern often with light yellow speckle. Sometimes small, yellow ring spots may develop on upper leaf surface. Infected fruits are small and misshapen with very hard rind and small pulp cavity. When affected fruit is cut, the inside rind tissue may have brown spots. Some strains of the virus cause cracking of affected fruits.

They are spread by aphids (Aphis gossypii, Myzus persicae) and pruning knives. The virus has a wide host range including bananas, cucurbits and many weeds.

Management:

• Use clean planting material
• Clean pruning tools
• Use resistant hybrids, or rootstocks of yellow passion fruit
• Removing diseased vines from the field
• Do proper weeding
• Avoid planting bananas and cucurbits near passion fruit fields
• Control aphids.

1.6. Aphids (Aphis gossypii and Myzus persicae)

Aphids damage plants by sucking plant sap causing curling, wrinkling or cupping of infested leaves, giving deforming plants. They spread viruses and excrete honeydew, which coat the plants and leads to growth of sooty mould, which can diminish the photosynthetic capacity of plants.

Management:

• Plant the crop in well prepared, fertile land, but do avoid applying too much nitrogenous fertilise, as this will make the plants juicy and attractive to aphids.
• Prune to avoid dense canopy, do not intercrop with alternate hosts like Cucubitaceae and Solanaceae crops, enhance natural enemies by incorporating natural habitats of agro-forestry and flowers strips around field.
• Use pesticides only if necessary. Lambda-Cyhalothrin, Cypermethrin, Amidacloprid Acetamipride, etc. are recommended, at the rate of 1m/1 litre of water.

7. Thrips damage on passionfruit

Thrips (Thysanoptera sp.) cause stunting of young plant. They feed on leaves, flowers, and fruits. Attacked plant parts shrivel. Attacked flowers and young fruits fall prematurely. Feeding by thrips on fruits causes tiny lesions, which affect the marketability of the fruit, especially in fruits for export.

Management:

• Destroy all plant residues and volunteer plants during field preparation by turning them under while ploughing, apply mulch to reduce pupation.
• Spray insecticides like Deltamethrin at the rate of 1ml/1litre of water.
• Natural enemies of thrips are important for natural control. Main natural enemies include anthocorid bugs (Orius spp.) predatory mites and spiders.

Harvesting: Passion Fruits

The fruits are ready for harvesting 8 months after planting. It is good to let the fruits fall off the plant and pick them from the ground. Once gathered, place the passion fruits in a cold, dry place: 4-6°C, with a high level of humidity. To give the fruits a smooth and even appearance, seal them in plastic bags. Fruit for the export market should be harvested before falling off the plant but when they are completely purple. The yield ranges between 15 and 20 Tons per Hectare.

Post harvest Management: Passion Fruits

The fruit is of easy preparation. One needs only cut it in half lengthwise and scoop out the seedy pulp with a spoon. For home use, many people do not trouble to remove the seeds but eat the pulp with cream and sugar or use it in fruit salads or in beverages. Some people usually squeeze it through two thicknesses of cheesecloth or pressed through a strainer to remove the seeds. Mechanical extractors are, of course, used industrially. The resulting rich juice, which has been called a natural concentrate, can be sweetened and diluted with water or other juices (especially orange or pineapple), to make cold drinks.

Passion fruit juice can be boiled down to a syrup which is used in making sauce, gelatin desserts, candy, ice cream, cake icing, cake filling or in cocktails. The seeded pulp is made into jelly or is combined with pineapple or tomato in making jam. The flavor of passion fruit juice is impaired by heat preservation unless it is done by agitated or “spin” pasteurization in the can. The frozen juice can be kept without deterioration for 1 year at (-17.78º C) and is a very appealing product.

The marketing of passion fruit is predominantly the fruits. It would, however, be of greater economic benefit to market a processed product like juice. For fresh fruit markets, especially the export market, fruit is picked after full colour development when the whole fruit is purple or canary yellow, but before shriveling and drying set in.