Propagation and Trellising of Passion Fruit plants
How to propagate passion fruit plants
In general, passion fruit can be propagated by (fresh) seeds, cutting, grafting, and air layers. In all cases, it is essential to use disease-free planting materials.
Passion fruit propagation by seeds
Propagation by fresh seeds is one of the most popular and widely used ways to propagate passion fruit as an ornamental and for commercial cultivation (fruit production). Generally, passion fruit seeds have a relatively low propagation (compared to other crops). To have the best germination rate possible (up to 70-85%), it is essential to use fresh seeds (directly after the harvest of the fruit or up to 3-6-month-old seeds) from ripe fruit. Ideally, growers are advised to use seeds as fresh as possible that have been kept moist in a shaded place (or within the ripe fruit) and sow them at a depth of 1 cm (0.4 in). Depending on the species and the passion fruit variety, seed germination could occur 1-2 weeks after planting to up to 3 months after planting. A temperature around 30 °C (85 °F) can speed up the process.
Moreover, washing the seeds to remove the pulp and light drying at room temperature will improve germination. In some cases, farmers may scarify the seed coat, nicking the edge of the seed with a knife and soaking it overnight to increase germination. After the germination, seedlings should be kept in individual pots, in the shade, and gradually exposed to direct sunlight. The young passion fruit plants can be transplanted in the open field when they are 25-40 cm (10-16 in) tall (3 months after germination).
Passion fruit vegetative propagation
Passion fruit propagation by grafted plants
One simple way of propagating passion fruit vines is by grafting. The advantage derived from this method is the early fruiting of the tree and the specific knowledge of what variety the plant will bear. It is the surest way of perpetuating the desirable characteristics of parent plants and the good qualities of the fruit.
Advantages of grafting
- Grafted trees come into bearing earlier than grafted ones.
- Grafted passion fruit vines tend to spread out as compared to ones from seedlings which tend to grow upright.
- Grafted passion fruit vines tend to be shorter and thus easier to harvest, spray and carry out other activities.
- Grafted passion fruit vines maintain the desirable characteristics of the mother plant e.g., fruit quality.
Usually, purple passion fruit is grafted onto a yellow passion fruit rootstock to obtain a plant with superior fruit quality and good drought tolerance, and resistance to nematode and disease problems affecting the root system (offered from the yellow passion fruit rootstock).
Both the stock and scion should be about 45 cm (18 in.) tall and have a stem diameter about that of a pencil when grafted. Scions should be about 8-10 cm (3-4 in.) long and contain at least 2 nodes. The stock should be cut off 25-30 cm (10-12 in.) above the soil line.
Various styles of grafting exist, which include wedge, side, T graft, and whip grafting. The following is an example of wedge grafting.
Things needed in passion fruit Grafting
- One-year-old passion fruit vine seedling.
- Scion with pronounced bud.
- Sharp knife for cutting the scion and the stock.
- Black plastic pouch with hole, 5 inches in diameter.
- Grafting tape to wrap the connection of the scion to the stock.
For grafting, a long, slanting cut is made from 1 side to the other through the base of the scion for about half its length, and a similar cut is made through the stem of the stock either a cleft graft, whip graft or side-wedge graft may be made. The 2 cut surfaces are then placed together, tied firmly with budding tape, and enclosed in a small plastic bag to maintain good moisture and temperature until the union is completed. When enough leaves appear on the grafted plant, you can loosen the grafting tape and remove all the shoots that develop below the graft union. The new plant can be planted when the leaves of the shoots are already mature.
Passion fruit propagation by cutting
Passion fruit can also be propagated by using cuttings obtained from healthy and productive mother plants. Each Semi-hardwood cutting should be taken when the vine is actively growing and have 2 to 4 nodes, and all except the top leaves should be removed. The propagator can treat the bottom 5-10 cm (2-4 in) end of the cutting with rooting hormone and place the bottom 2/3 of the cutting in a suitable growing medium. Porous soil, black or beach sand, sawdust, vermiculite, and wood shaving can be used as rooting media. Until they root, the cuttings should be kept in a warm place with high humidity. Rooted cutting can be transplanted on the field when they are 15-16 cm (6 in) tall. Despite the possibility of reproducing passion fruit by cutting, this technique is not very popular for commercially cultivated plants due to the less vigor of the plants coming from cuttings than those produced by grafting or seedlings.
Trellising of passion fruit – How to support the passion fruit plants
Ideally, the orientation of the trellis should be north-south to maximize the sun exposure of the vines. In areas where strong winds are a problem, it is important to arrange the trellis parallel to the direction of the wind.
There are many different types of trellising systems that can be used for supporting passion fruit vines. However, the most common is the T-type having a cross arm and 2-4 horizontal wires on the top (or near the top) of each post.
It is essential to use poles and wires (no. 9 or 10 galvanized steel) that can withstand the weight of the passion fruit vines even in years with high vegetative and fruit production and under strong winds. Additionally, the poles should be tall enough, up to 7 m (15 ft.), to allow the vines to grow sufficiently. Up to 45-75 cm (18-30 in.) of the pole should be in the ground, and if it is made of wood, they need to be treated with wood preservative to reduce termite attack and prolong the life of the pole. For uniformity and maximizing production, the spacing of the passion fruit plants should be directly related to the spacing of the trellis poles. Usually, there are two plants growing in the space between 2 poles (0.6-2 m or 2-6.5 feet distance). In years with very high production, the farmer may use extra poles to support the canopy and wires between two poles.
References
Further reading
- Passion Fruit: History, Uses and Nutritional value
- Passion fruit: Types-Varieties of Passion Fruit and Plant Characteristics
- Passion Fruit: Soil & Climate Requirements, Land Preparation and Planting
- Propagation and Trellising of Passion Fruit plants
- Training and Pruning of Passion Fruit Plant
- Passion Fruit Plant Care: Irrigation and Fertilization of Passion Fruit
- Important Passion Fruit Diseases
- Important Passion Fruit Pests
- Passion Fruit: Harvest, Yield and Storage
