Sunday 3 June 2012

Passion fruits growing in Kenya [Passiflora spp]

Passion fruits are used for extraction of delicious juice, flavouring salads or they may be eaten fresh on their own. There are two major varieties of passion fruits plants grown in Kenya namely Passiflora edulis and Passiflora flavicarpa. Passiflora edulis is purple in colour when ripe,very acidic, and variable in taste and juiciness, with intense aromatic scent and round shape. passiflora flavicarpa is yellow when ripe and oval in shape. There are many selections and hybrids with the yellow passiflora flavicarpa, which are bigger, with similar taste but possibly less aromatic and more acidic. Both varieties are green before ripening. The Purple passion fruits/passiflora edulis are subtropical while yellow passion fruits are more suited to the tropics and grow well in tropical countries like Kenya. Passiflora flavicarpa are the most widely grown passion fruits for commercial purposes globally. They are grown for the local and export market in Kenya.

Requirements for growth are warm to cool climate, altitude range of 1000-2000M with minimum rainfall of 900mm per year, medium textured deep well drained loamy soils and a growing site which is protected from strong winds. Commercial life of passion fruits is about 5 years. Therefore initial land preparation should be deep to allow good root establishment and growth. The passion fruits are grown from seeds. Passion fruits seeds have low viability and should be planted within 3 months of extraction. A single piece can yield as many as 250 small hard dark-brown or black seeds. Soak the seeds for 48 hours to improve germination, prepare a seedbed one meter wide, sow seeds in furrows 30cm apart and cover lightly with soil and apply vegetation mulches. The mulches should be removed after germination. Thin seedlings to 5cm apart when they are 5cm high; Top-dress with 300gm CAN fertilizer per 4 square metres to stimulate rapid growth. The recommended field spacing is 2M× 3M in un-mechanized growing and 3M× 3M in mechanized growing giving plant population of 1600plants/ha and 1100plants/ha respectively. One month after transplanting passion fruits seedlings, application of 120g CAN, fertilizer is recommended .Subsequent fertilizer applications during the life of the crop have not shown growth improvement.
Dig holes at 45× 45cm at least 3 weeks before transplanting into the growing field and separate top soil and subsoil. Mix the top soil with 10kg of manure and 125gm of D.A.P fertilizer. Fill the hole with this mixture using extra top soil if necessary. Transplant the seedlings at the beginning of rains early in the morning or late evening and at the same depth as they were in the nursery. Apply water to settle the soil around the roots, and shade the seedlings in hot areas. Passion fruits are climbing plants and hence trellis for support should be constructed before transplanting. To construct the trellis 2.70M long posts with a diameter of 15cm are placed in holes 60cm deep and spaced 6M apart in the row, fixing the end posts firmly in the ground. Stretch a single strand wire tightly along the top of each row of posts. The whole structure should be capable of withstanding the subsequent weight of the crop. Training should be done to allow the vine to climb upon the trellis wire. Sisal twine is tied at the base of each plant to the wire above. Two healthy shoots of the plant are selected at the base of the plant and trained by twisting them up the sisal twine. All other shoots and side branches below the wire are removed regularly. When the two main shoots reach the wire they are trained along it by twisting and tying.

Passion fruits pruning involves regular removal of tendrils which causes the vine to entangle, to ensure that lateral side branches hang down freely. Any side lateral trailing on the ground should be cut back 15cm from the ground. After harvest side laterals should be cut back to a newly developing laterals as close to the main leader as possible. Where no new side shoots have formed the exhausted lateral should be cut at 3rd to 5th node from the main leader. Keep the field free of weeds all the time and you may intercrop with a low growing annual crop during the first year. Irrigation will keep the crop growing and flowering throughout most of the year increasing yields. Passion fruits come into maturity 6-8 months after transplanting. The main harvest is obtained 12-13 months after planting. Pick only ripe purple passion fruits from the vine. The economic life of a well maintained orchard is about 5 years. There normally two passion fruits harvesting peaks in Kenya which are July-August and December-January. Pests of economic importance destroying various plant parts include Kenya mealy bug, giant coreid bug, stink bugs, aphids, yellow mites and systate weevil. These should be controlled using suitable methods. Woodiness is a viral disease of passion fruits which retards growth and it’s controlled by uprooting and burning affected plants with immediate effect. Brown-spot is a fungal disease of passion fruits controlled by application of fungicides.