Carica papaya (papaya)

Japanese name: パパイヤ
Scientific name: Carica papaya

[Overview]
An evergreen small tree 5–10 m tall.
When the trunk, leaves or fruit are damaged, they exude a white milky sap.
The trunk is soft, usually unbranched, and erect.
Scars left by fallen leaf stalks and fruits are conspicuous on the trunk.
The leaves are spirally alternate and clustered at the top of the trunk, sometimes reaching 90 cm in length including the petiole; they are palmately divided into 7–11 lobes, the lobes are further cut, and the veins are conspicuous.
The petioles are thick and often tinged with purple.
The plant is usually dioecious, but some strains bear bisexual flowers and set fruit on a single plant.
It flowers all year round if the temperature is sufficient.
The flowers are white to cream-colored with 5 petals; male flowers are borne in large numbers in inflorescences arising from the leaf axils, and female flowers are usually solitary.
The fruit is a berry 10–45 cm long and 10–30 cm in diameter, spherical to oblong with 5 blunt ridges, and it is said that some large cultivars have fruits weighing over 10 kg.
The fruit is at first dark green and hard, and turns orange-yellow to yellow when ripe.
The flesh is orange-yellow to red-orange, soft and juicy, with a distinctive smell and flavor, and many round black seeds are attached inside the hollow center.

[Uses]
The fruit is eaten fresh or as dried fruit, and the unripe fruit (green papaya) is used as a vegetable in salads and other dishes.
The leaves are used as a folk medicine.
Papain, a protein-digesting enzyme contained in the milky sap, is used as a meat tenderizer, in facial cleansers, and for medicinal purposes.

[Cultivation]
Propagate mainly from seed, but cuttings and grafting are also possible.
The optimum temperature for growth is 22–26 °C; a minimum of 15 °C or higher is required, and growth stops below 10 °C.
In warm regions from southern Kyushu southward, it can be grown outdoors.
Frost damage causes the leaves to fall and the growing point to die.
It prefers sunny, well-drained soil.
In poor sunlight it becomes leggy and the rate of fruit set declines.
Also, it easily dies if the soil becomes waterlogged.
Avoid places exposed to strong wind, as the leaves are damaged and the tree may fall over.
For potted plants, water thoroughly when the soil surface dries from spring to autumn, and keep on the dry side in winter.
For plants in the ground, rainfall is sufficient.
From spring to autumn, apply a fertilizer low in nitrogen, placed on the soil.
Pests and diseases include powdery mildew, anthracnose, root rot, white scab, aphids and spider mites.

View this page in Japanese (日本語)