Detailed Guide to Passion Fruit Seedling Cultivation: Grow Strong and Healthy Fruit Seedlings

Passion fruit is a herbaceous vine of the genus Passiflora in the family Passifloraceae, about 6 m long; the stem has fine stripes and is hairless; it has 5 petals, equal in length to the sepals; the base is pale green, the middle is purple, and the tip is white; the berry is ovoid, 3-4 cm in diameter, hairless, and purple when ripe; the seeds are numerous and oval. The flowering period is June, and the fruiting period is November.

It grows wild in valley thickets at an altitude of 180-1900 m. It is native to the Antilles and is widely planted in tropical and subtropical regions. There are mainly two major categories: purple fruit and yellow fruit. The lifespan of the plant is about 20 years, and the economic lifespan is generally 8 to 10 years.

The fruit can be eaten raw or used as a vegetable or feed. Used as medicine, it has stimulating and tonic effects. The fruit pulp is juicy; after adding calcium bicarbonate and sugar, it can be made into an aromatic and delicious beverage, and it can also be added to other beverages to improve their quality. The seeds are pressed for oil, which can be used for food and for making soap, paint, and so on. The flowers are large and beautiful, without fragrance, and can be used as ornamental garden plants. In regions outside China, passion fruit has such laudatory titles as “king of fruit juice” and “money tree”.

I. Bare-root seedling cultivation technique

1. Seed selection

During the fruit ripening period, select fully mature fruit that is large, juicy, thin-skinned, and free of pests and diseases from superior mother plants, take out the seeds, wash them clean, and dry them in the shade for use as seedling propagation material. Seeds from the current year sown in the current year have a high germination rate, reaching more than 95%. The seedling cultivation time is generally from September to May of the following year.

2. Preparation of the nursery

Deeply plow and sun-expose the soil for 5-7 days. Rake it fine and form beds, with a bed height of 20 cm and a width of 80-100 cm. Leave a path 40 sq cm wide between beds. Remove miscellaneous items such as stones and tree roots from the nursery. When forming the beds, apply 7.5 kg of calcium magnesium phosphate fertilizer or superphosphate per 100 sq m of nursery. Mix it thoroughly with the topsoil and level the bed surface.

3. Seed treatment

Soak the seeds in water for 2-3 days, and rub them by hand to remove the gelatinous outer layer of the seeds. Mix 10-15 g of carbendazim or thiophanate-methyl per 1 kg of seeds; after mixing for 20-30 minutes, sowing can be carried out.

4. Seed germination promotion

Prepare the germination bed in the same way as the nursery. After the germination bed is prepared, evenly scatter the seeds on the germination bed and cover with a 1-2 cm layer of fine river sand. Then cover with a 5 cm layer of grass. Water thoroughly. Surround the germination bed with plastic sheeting to form a wall 60 cm high to retain moisture and prevent rats. Build a shade shed or install a shade net to maintain 40%-50% shade. After sowing, water once every 3 days, open the shade shed for ventilation for 1 day, and close the shed at 7:00 p.m. After 7-10 days, the seeds begin to germinate and some emerge from the soil; at this point remove the covering grass and the plastic wall.

5. Transplanting

Before transplanting, the nursery should be covered with a shade net or equipped with a shade shed to maintain 10%-50% shade. When the seedlings grow until the cotyledons are stable, they can be transplanted from the germination bed. Before lifting the seedlings for transplanting, water thoroughly first to make lifting easier, and take care to preserve the root system. The transplanting depth should be the depth at which the seedlings grew in the germination bed. Seedlings should be transplanted as soon as they are taken. After transplanting, water thoroughly to settle the roots.

6. Nursery management

After transplanting, water once every 2 days to keep the nursery moist. Remove weeds in the nursery; every 15 days, spray with 15 kg of water plus 15 mL of dichlorvos and 15 g of thiophanate-methyl to prevent and control pests and diseases. Within 10 days after transplanting, if missing plants are found, replant them promptly. After the seedlings grow two true leaves, apply a light application of nitrogen and phosphorus, spraying with 0.1% urea and 0.2% potassium dihydrogen phosphate solution once every 7 days to promote good seedling growth.

7. Leaving the nursery

After the seedlings grow for 60-80 days, the stem diameter can reach 0.3-0.5 cm and the height can reach 30-40 cm, and they can leave the nursery for field planting. Twenty days before leaving the nursery, gradually reduce the shade in the nursery, or remove the shade net 10 days before leaving the nursery, to harden the seedlings. Before lifting the seedlings, water the seedbed thoroughly to make lifting easier. After lifting the seedlings, promptly cut off part of the leaves (generally one third) and excessively long roots, and promptly coat the roots with mud to facilitate transport and ensure the survival rate after planting.

II. Bagged seedling cultivation technique

1. Seed selection

Seed treatment, seed quantity used, nursery establishment, seed germination promotion, transplanting, nursery management, and leaving the nursery are the same as for the bare-root seedling cultivation technique.

2. Nursery preparation

Remove weeds and stones from the nursery to make it clean and level. The seedbed is 100 cm wide and recessed 3-5 cm, with a 40 cm wide path left in the middle. Dig drainage ditches around the nursery to prevent water accumulation.

3. Soil selection, bag filling, and bag arrangement

Use fertile loam as the nutrient soil. To raise 1000 seedlings, evenly mix 7.5 kg of superphosphate or calcium magnesium fertilizer with enough nutrient soil. When filling the bags, fill them firmly and fully with nutrient soil. The filled nutrient bags should be arranged neatly on the seedbed, 15 bags per row. After arranging them, compact the surrounding area with soil.

4. Transplanting

Leaving the nursery is basically the same as for bare-root seedlings, but bagged seedlings can be transplanted when the seeds germinate and expose the cotyledons. When the seedlings grow to 4-5 true leaves in the nursery, they can leave the nursery for planting.