Climatic requirements are as follows:

Altitude range

Altitude requirement ranges between 0-2000 m.a.s.l. depending on the variety. Purple passion (e.g. Esther variety) prefer cooler, high altitude areas (1200-2000 m.a.s.l). The Sweet Yellow varieties do well in low to mid altitudes areas (0-1500 m.a.s.l).

Soil type and conditions

Passion grows in a wide range of soils but performs best in deep, fertile, well-drained and well-aerated sandy loams or similar medium textured soil. A pH of between 5.5- 7.0 is optimal. Liming is necessary if the soil is too acidic.

Temperature range

For optimal production, temperatures should be in the range 16-30^oC.

Rainfall

An annual rainfall of about 900-2000 mm is suitable for an optimal production. Excess rainfall leads to poor fruit sett and also encourages disease incidences.

Passion fruit has a deep root system, therefore, land must be properly cultivated.

Recommendations for land preparation

(1) Consider minimum tillage to conserve soil, water and nutrients, and to reduce cost and workload.

(2) Clear the land. The cut vegetation will provide green mulch that should be in cooperated back into the soil when ploughing.

(3) Ploughing can be done using chisel ploughs, hand hoes, oxen or tractor drawn implements. Plough deep and harrow; and ensure the hard pans are removed before planting.

• Seed propagation

Seedlings are first raised in nursery beds or bags. Quality seeds should be got from the best fruits of selected healthy plants.

Raising seedlings in nursery

• Prepare nursery beds of 1 meter wide & required length.
• Treat the seeds with hot water at 50⁰C for 15-30 minutes to break seed dormancy. Alternatively, Seeds can be soaked in ‘optimizer’ 20ml/litre overnight to break the dormancy.
• Plant treated seeds in furrows, 30cm apart.
• Cover seeds lightly with soil.
• Mulch with a thin layer of grass. Remove mulch after germination. Seeds germinate in 10-15 days.

The seedlings raised in a nursery bed grow slowly hence they are transplanted 3-4 months at a height of 15-25 cm.

          Seeds

Raising seedlings in bags.

• Raise seedlings in bags, 15cm wide and 25cm deep. Use seeds stored for less than 3 months.
• Treat them (seeds) with hot water at 50⁰C for 15-30 minutes.
• Sow three seeds per bag and cover lightly with soil. Germination takes 2-3 weeks.
• Thin after two months to leave only one seedling/bag.

Transplant at the start of the rainy season.

• Grafts

Grafts are got by joining rootstock and scions of different passion varieties. Grafted seedlings can be obtained directly from a recommended and reputable source (nursery).

Raising rootstocks for grafting

The yellow passion have desired rootstock characteristics, therefore, is recommended for rootstock in grafting while the purple passion is recommended for use as scions.

Seedlings as rootstocks take 2-3 months in the nursery.  Cleft graft after 3-4 weeks (when 45 cm tall) to the purple passion fruit scions.

Grafting perpetuates hybrids for tolerance and good yields.

• Cuttings

Cuttings should be gotten from an actively growing young and newly mature wood with 2-3 internodes. Set them in coarse sand and later transplant into bags or a nursery bed.

Undertake proper management practices such as watering and hardening off..

Passion fruit varieties include;

• Yellow passion fruit,
• Sweet passion fruit (KPF4, KPF11, KPF12),
• Purple passion fruit,
• Banana passion fruit,
• Giant passion fruit,
• Esther variety

Prepare planting holes 45 x 45 x 45 cm, spaced at 2metres within rows and 3 metres between rows. Fill the holes with topsoil mixed with up to 10kg of compost or manure.

Add fertilizers to the soil in the right amounts to provide the required plant nutrients for vigorous crop growth.

Transplant at 3 weeks after grafting at the start of the rainy season; and firm down the soil around the plants to establish good root and soil contact. Keep the grafted spot out of contact with soil to avoid fungal infection.

Transplanting 

Water transplanted seedlings to ensure quick rooting and establishment of the plant

Spacing of 2 by 3m is recommended for hand cultivation and 3 by 3m for mechanized cultivation. Commercial plantations should adopt a row spacing of 1.2-1.8 m and a within-row spacing of 3m. This gives around 1900- 2700 plants per ha.

Control the weeds timely and appropriately. When the crop is still young, weeding can be done manually. However, in later stages of development, herbicides can be used to kill all kinds of weed.

Mulching also helps in managing weeds.

Proper nutrition can be achieved through the use of both basal and foliar fertilizers.

Basal fertilizers should be applied in the soil at planting and at top dressing based on the recommendations of soil testing. DAP can be used at planting because it is majorly rich in P, which is highly needed at early growth stages of plant growth. CAN is essential for top dressing.

Ensure application of 1-2 debes of manure per year per plant before rains.

Foliar and trace elements should be applied at every 3 months based on the recommendations of soil testing and analysis.

Crop rotation: Passion fruit should not be grown for more than 5 years on the same plot.

Pruning and training: Trellising should be done at 2.7m high. Wooden posts of 15cm diameter for plants to climb and well-made metal wire used over the top of the posts.

Train 2 healthy shoots above the graft union with sisal strings.

Prune to remove old unproductive shoots and dead wood.

Pruning enhances aeration and light penetration for flowers and fruits production. All pruned plant parts should be sprayed copper-based fungicide to avoid fungal infection.

(i)Nematodes

Amongst nematodes infesting passion fruit are Root-knot nematode (Meloidogyne spp).

Symptoms/Damage: Small lumps (root knots or galls) on the roots. Heavily infected roots are severely distorted and swollen.  Affected plants are stunted with yellowing of leaves and eventually wilt. Affected roots rot.

Control

• Crop rotation with non-host plants eg cassava brassicas, cereals.
• Avoid fields where susceptible crops (eg Tomatoes, okra, egg plants) have been previously grown.
• Use tolerant rootstocks (eg P. caerula)
• Use mixed cropping eg grow marigolds (Targetes spp) or sunhemp (Crotalaria juncea) as mixed crop.
• Maintain high levels of organic matter in the soil (manure or compost).
• Ammend the soil with neem cake (nematicidal).
• Apply appropriate chemical control (nematicides) eg nemacur, Furadan, Rugby.

(ii)Leaf miner  

Symptoms/Damage: The maggots feed between the upper and lower epidermal leaf surfaces creating whitish serpentine or blister mines. Heavily attacked leaves may drop off. This reduces the surface area for photosynthesis leading to stunting and reduced yields. 

Control

• Plant clean material free from all stages of the moth.
• Rotate with non-host crops such as maize, beans.
• Remove and burn all infested leaves, infected crop residues and wild host plants around the farm.
• Biological control: -Use of natural enemies eg Bacillus thuringiensis controls outbreaks.
• Use sex pheromone traps on the males to reduce populations due to reduced fertiliz
• Spray using appropriate insecticide eg spinetoram, Corragen, etc, if pest population is high. Neem products are also effective in controlling leafminers.

(iii)Mealybugs (Planococcus citri and P. kenya)

Mealybugs  infest fruits and foliage.

Symptoms/Damage: Bugs suck sap from the growing tips or developing fruits.  The bugs pierce the terminal buds, which eventually wilt and die back. Young plants may be killed if the attack is severe. The punctured young fruits develop localised hardened spots  that remain on the fruit reducing their market value.

Control

• Conserve natural enemies. Mealybugs are usually controlled by a wide range of natural enemies.
• Hand pick and destroy in small orchards.
• Dig and destroy sprouting stumps or old crops left in the field. They provide refuge for the bugs.
• Intercrop passion fruit with repellents such as garlic, onion to reduce infestation.
• Spray using recommended pesticide 

(iv)Aphids 

Symptoms/Damage: Aphids are tiny black and green soft- bodied insects which suck sap from leaves and stems of the plant. Infested leaves curl, wrinkle or cup, giving plants a deformed shape . Their excreta, honeydew, enhances the growth of sooty mould which diminishes the photosynthetic capacity of the leaf. Aphids also spread viruses. 

Control

• Aphids are usually controlled by natural enemies.
• Apply insecticidal soaps or oils such as neem.
• Spray with appropriate insecticides eg Kingcode Elite 50EC, Pentagon 50EC, if infestation is high.

To get rid of the sooty mold, spray with Jambo clean (100ml/20L).

(v)Thrips 

Symptom/Damage: Thrips feed on leaves, flowers and fruits. Attacked plant parts shrivel, flowers and young fruits fall prematurely. Lesions on fruits and distortion of leaves and young shoots. Young plants get stunted. 

Control

• Cultural practices like tilling in plant residue, destroying plant residues and volunteer plants; apply mulch to reduce pupation
• Planting resistant/tolerant varieties
• Use natural predators like predaceous mites, spiders, lacewings, anthocorid bugs.
• Use botanical extracts e.g. Neem extracts can be sprayed on plants attacked.
• Spray recommended insecticides eg profile, Actara, Match, Dimethoate. 

(vii) Broad mite Caterpillars or yellow tea mite (Polyphagotarsonemus latus)

Is the most important mite pest of passion fruit in Kenya. They are tiny and cannot be seen with the naked eye, and are even difficult to detect with a hand lens. 

Symptoms/Damage: Their feeding causes discolouration, necrosis of tissues and deformation. Initial attack occurs on

Stems or terminal shoots and young terminal leaves. Attacked young leaves are stunted, deformed (slender, twisted or crumpled), fail to elongate and finally may wilt and dry. Stems of terminal shoots may become slightly swollen, roughened or russeted. As a result, the growth of the plant is affected and flower production reduced causing considerable yield reduction. Attacked fruits become deformed and show white to tan or brown scars on the skin, affecting their market value. Severely attacked fruits may fall. 

Control:

• Remove and burn infested plants to prevent spread.
• Manage alternative host weeds
• Use natural predators –lacewings, ladybugs and predatory mites .
• Sprays of water, insecticidal oils, or soaps can be used for management.

Apply appropriate miticides if pest population is high eg Bazooka 18EC, escort, Alonze 50EC.

(i)Fusarium wilt (Collar rot)

Caused by many forms of the soil-inhabiting fungus Fusarium oxysporum. 

Symptoms/Damage: Yellowing of leaves and the collar region of the affected plant, at soil level, turns brownish and vertically cracks. The vines wilt, followed by a complete collapse of the plant.

On dissection of the stem, vascular tissues show brown discolouration.

Control

• Use certified disease free seeds
• Grafting to wilt-resistant yellow passion fruit rootstocks (eg P. caerula) is the most practical way of control.
• Apply 3-4 years rotation, with non-susceptible crops like the cereals (eg maize, sorghum).
• Field sanitation practices: -Remove and burn infected plants as soon as possible to check the spread of the diseases. 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.

(ii)Brown spot (Alternaria passiflorae)

Caused by Altenaria passiflora (fungal) enhanced by lack of aeration

Symptoms/Damage:

Symptoms appear as brown spots on the leaves, often extending along the veins and drying out in the centre.

On the stems, spots are upto 30mm 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 producing red-brown spore masses.

Control

• Grafting to resistant yellow passion fruit rootstocks. Yellow passion fruit and its hybrids are more tolerant to this disease.
• Field sanitation; collection and disposal of fallen diseased fruits, leaves and vines.
• Pruning vines to reduce density, promote air flow, and allow light penetration, thereby reducing humidity within the crop.
• Timely sprays with copper based fungicides.

(iii)Septoria spot (Septoria passiflorae)

Caused by fungi Alternaria spp. Prolonged rains and mild temperature favours the disease development.

Symptoms/Damage: The disease attacks leaves, stems and fruits. Brown spots upto 2mm with minute, black dots (fruiting bodies containing fungal spores) develop on leaf surface. 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.

Control

As for brown spot disease.

(iv)Phytophthora blight

The disease is caused by a fungus (Phytophthora spp.). It affects both the yellow and purple passion fruit.  The disease causes root rot, wilt, damping off and leaf blight; and its development is favoured by wet, windy weather.

Symptoms/Damage:

Affected leaves are water-soaked and light-brown in colour. The leaves fall readily (defoliate), leading to death of the vines.

Affected areas of the stem are first purple and later brown above the graft union. This may completely girdle the stem causing wilting and collapse of the vine. 

Affected fruits show large, water-soaked areas. Diseased fruits fall readily and in wet weather become covered with white, fungal growth.

Control

• Use rootstocks that are resistant to the disease for grafting.
• Field sanitation; collection and disposal of fallen diseased fruits, leaves and vines.
• Pruning vines to reduce density, promote air flow, and allow light penetration, thereby reducing humidity within the crop.
• Mulching will minimize germ splash to the lower leaves.
• Improve drainage to help manage the disease.
• Timely sprays with copper based fungicides every 2-3 months during the wet season reduces incidences. Other fungicides that can help include Famoxadone + Cymoxanil, Mancozeb and Metalaxyl + Mancozeb.

(v)Passion fruit Woodiness potyvirus (PWV)

Cause: A virus

Symptoms/Damage:

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 cut, the inside rind tissue may have brown spots. Some strains of the virus cause cracking of affected fruits.

Control

• Use virus-free planting material.
• Use resistant hybrids or rootstocks of yellow passion fruit.
• Do proper weeding and remove diseased vines from the field.
• Avoid planting bananas and curcubits near passion fruit fields.
• Disinfect grafting and pruning tools with household bleach.
• Control the vector (aphids)

Maturity is determined by time after transplanting after bloom and external skin colour changes from green to yellow or purple, depending on the type of passion fruit.

Seeded yellow passion fruit matures in 10 months after transplanting with full production occurring after 18 months

Grafted passion fruits begin initial production after 7 months

Harvest is done manually by cutting or clipping the fruit off the vine using sharp knife or clippers with a sharp edge 

Passion fruit for processing fruit drops to the ground when fully mature and they look shrivelled and unattractive, hence they are collected every second day.

For fresh fruit and export markets fruits are picked after full colour development when the whole fruit is purple or canary yellow but before shrivelling and drying sets in.

Pack in 4.5 and 6 kg fibreboard cartons, sometimes in one or two layer trays or cell packs

Passion fruit subjected to free aerated place will shrink

Harvested fruits should be handled with care and they should be placed in a plastic bucket or field container without dropping or throwing them.

The harvesting container should also be clean to avoid any contamination.

Much higher yields are possible e.g. 50 tons per ha annually for purple passion fruit in Kenya. Yields increase up to 3^rd year. Beyond that the yields decline.

Yields of over 6-8 tons per acre are attainable on Purple variety and 8-10 tonnes per acre of Esther purple variety.

Passion fruit is processed to make juice and jam.

Juice

Jam