Njaval Pazham (Black Jamun) Fruit Plant

Syzygium cumini, commonly known as jambul, jambolan, jamblang, or jamun, is an evergreen tropical tree in the flowering plant family Myrtaceae. It is native to the Indian subcontinent and adjoining regions of Southeast Asia.
This slow-growing species can reach up to 30 meters in height and may live for more than 100 years. Its dense foliage provides excellent shade, and it is also grown for ornamental purposes. The bark is rough and dark grey at the base, becoming smoother and lighter higher up. The wood is water-resistant and is used in railway sleepers and for installing motors in wells. It is also used for making inexpensive furniture and village dwellings, though it is relatively difficult to work with.
Syzygium cumini trees begin flowering from March to April. The flowers are small (about 5 mm in diameter) and fragrant. Fruits develop by May or June and resemble large berries. The fruit is drupaceous, oblong to ovoid in shape. It changes color from green to pink, then crimson red, and finally black when fully ripe. A variant also produces white-colored fruit. The fruit has a sweet, mildly sour, and astringent flavor and is known for staining the tongue purple.

Fertilizing Jamun Trees

In the pre-bearing period, 20–25 kg of well-rotted farmyard manure or compost per plant per year should be applied. For bearing trees, this dose should be increased up to 50–60 kg per plant per year. The ideal time for applying organic manure is one month before flowering.
For mature trees, apply 500 g N, 600 g P, and 300 g K per plant per year. This should be spread near the canopy of the plant and mixed into the soil by hoeing.

Harvesting Jamun Fruits

Seedling jamun plants start bearing after 8 to 10 years of planting, while grafted plants bear after 6 to 7 years. However, commercial bearing generally begins after 8 to 10 years and continues until the tree is 50 to 60 years old.
The fruit ripens during June–July. A key sign of ripeness is a deep purple or black color at full size. Fruits should be harvested immediately upon ripening, as they cannot remain on the tree once mature. Harvesting is usually done by hand-picking while climbing the tree, often using bags slung over the shoulder. Care must be taken to avoid damage to the fruits. The average yield is about 80–100 kg per full-grown seedling tree and 60–70 kg per grafted tree annually.