JAMBOLAN or Jamun (syzygium) is an important indigenous minor fruit of commercial value. The tree is tall, evergreen, also grown for shade and windbreak. The fruit possesses considerable nutritive value.

It is a good source of iron, apart from the usual contents, e.g, minerals, protein etc. The nutritive value of this fruit is given below.

Jamun fruit is usually shaken with salt before eating which has spicy flavour. It is also used in making beverages, jellies, jam, squash, wine, vinegar and pickles.

Jamun squash is a refreshing drink in summers. Jamun syrup is beneficial in diarrhoea. Juice of Jamun and mango if mixed in equal quantity is good in quenching thirst of diabetic patients. Jamun wine is prepared, particularly in Goa.

The vinegar prepared from the slightly unripe fruit is stomachic, carminative and diuretic, apart from having cooling and digestive properties. Smaller fruits are used in beverage industry for being rich in acidity, tannins and anthocyanins. Its seed can be used as a concentrate for animals because it is rich in protein, carbohydrates, and calcium. Jambolan crop is easily grown in neglected and marshy areas where annual rainfall is between 1,500-10,000mm.

The fruit is black or purple in colour, sweet in taste. The fruit has received more recognition in folk medicine and in pharmacy. The juice of ripe fruit or a decoction of it is administered in spleen enlargement, chronic diarrhoea and urine retention.

The seed extract in liquid or powdery form are given to patients with diabetes mellirus or glycosuiria. In many cases blood sugar level drops quickly.

Dried alcoholic extract of Jamun seeds reduces blood sugar and glycosuria. Seeds contain an alkaloid, jambosine and glycoside jambolin or antimellin which halts the conversion of starch into sugar.

Seed extract lowers blood pressure by 34.6 per cent. The leaf juice is effective in dysentery either alone or in combination with the juice of mango. Jamun leaves may be helpful as poultices on skin disease. Leaves, stems, flower buds, open blossoms, and bark have antibiotic properties. A decoction of bark is good for dyspepsia, dysentery, and diarrhoea. Bark decoctions are taken for asthma and bronchitis and are gargled or used as mouthwash for the astringent effect on mouth ulcerations.

There are no named or standard cultivars of this fruit. The common cultivar grown in Pakistan is ‘Ra Jamun’. It produces big–sized oblong, deep purple or bluish black fruit. Its pulp is purple pink and fruit is juicy and sweet. The stone is small in size.

Climate and soil: Jamun is grown in tropical and subtropical climate. It requires dry atmosphere at the time of flowering and fruiting. Early rains are beneficial to proper growth, development and ripening of fruits. The young plants are susceptible to cold and drought conditions. The Jamun tree requires deep loam and well-drained soil. Its cultivation should be avoided in very heavy or light sandy soils.

Planting: Jamun can be transplanted in February-March or in July-August. The plants are transplanted with the soil ball intact. Jamun propagation is by seed. Seedling plants bears fruits of variable size and quality, such trees are generally hardy and long live for improved and selected true–to–type plants, vegetative methods of propagation, like inarching, budding, cutting, and air-layering are advocated.

Regular pruning is not required however in later years. The dry twigs and crossed branches are removed. In the early age, the plants require 8-10 irrigation in a year. Intercropping of Jamun orchard with suitable crop not only brings good income but also improves fertility of soil. A full dose of 20kg rotten FYM during the pre-bearing period of tree and at bearing stage 80kg FYM per tree should be supplied for proper growth and fruiting. Seeds sown fresh usually show a high percentage of germination within two or three weeks, but if stored they lose their viability rapidly.

Leaf eating caterpillar infests the leaves and may defoliate the trees. Treatment with Malathion is effective. White fly damages the tree in all parts, sometimes the fruits of Jamun get wormy due to attack of fruit fly.

The Jamun fruits are also damaged by squirrels, and birds such as parrots and crows. Ripe fruits are picked singly by hand and in all cases care is taken to avoid possible damage. The storage life of Jamun fruit is six days at room temperature and three weeks at low temperature. The average yield of fruit from a full grown Jamun tree is about 80-100kg and from a grafted one 60-70kg per year.