Jamun
Climate
Jamun is successfully grown under tropical and subtropical climate. It also occurs in the lower range of the Himalayas upto an elevation of 1300 metres and in the Kumaon hills upto 1600 metres above sea level. It is widely grown in the larger parts of India from the Indo-Gangetic plains in the North to Tamil Nadu in the South. It is one of the most hardy fruit crop and can be easily grown in neglected and marshy areas where other fruit plants can not be grown successfully. Jamun is somewhat more susceptible to cold and drought than the seedling mango trees. It requires dry weather at the time of flowering and fruiting. For ripening of fruit and proper development of its size, colour and taste, early rains are considered very beneficial. The fruits show remarkable improvement in these respects after the very first shower of rain.
Soil
Jamun tree is exact in its soil requirements. The tree requires deep, loam and well-drained soil for its optimum growth and good fruiting. Its cultivation should be avoided in very heavy or light soils.
Choice of Varieties :-
Ra Jamun : It produces big sized fruit with average lenght of 2.5 - 3.5 cm and of diameter 1.2 - 2.0 cm. Fruits are oblong in shape, deep purple or bluish black in colour at fully ripe stage. The pulp colour of ripe fruit is purple pink and the fruit is juicy and sweet. The stone is small in size. It ripens in the month of June-July. The variety is very common among the people.
Small sized Jamun : It is a late maturing variety. The average lenght of fruit is 1.5 - 2.0 cm and diameter is 1 - 1.5 cm. The fruit is slightly round in shape, deep purple or blackish in colour at full ripe stage. The colour of the pulp is purple, less in juice, weight and sweetness of pulp in comparison of that of 'Ra Jamun'. The stone is very large. Fruits ripen in the month of August.
Propagation and Rootstock :
Though lot of jamun plantation is seen on road side or scattered plantation at farmer's field, yet no single well established orchard is reported in North India. Also no systematic work has been done on its propagation.
The most common method of jamun propagation is by seed. Seedling plant bears fruit of variable size and quality. For improved and selected true-to-true, vegetative methods of propagation like inarching and air-layering have been advocated.
Sexual Propagation : Seeds are sown fresh in flat nursery beds during July when this fruit ripens. The seeds should be sown at a distance of 15 cm in rows which are 25 - 30 cm apart. The seedlings can also be raised in polythene bags of 22.5 - 30 cm size. The bags should be filled with a mixture of soil and farmyard manure in equal proportion. To drain out excess water the polythene bags should be pricked from all sides before filling the mixture. It has been seen that more than one seedling comes out from a single seed. These seedlings are separated in different bags when they are about two weeks old.
Plants grown from seed become transplantable during next spring season. But it is advisable to keep them in nursery upto next rainy season which is the best time of its plantation.
Vegetative Propagation :-
T-budding and patch budding : According to the recent research conducted at Punjab Agricultural University has revealed that jamun can be best propagated through T-budding as well as through patch buddding. The seedling of jamun is used as a rootstock. The per cent success is higher in T-budding (70%) than patch budding (60%). The best time for budding in both the cases is either during February-March or during August-September. However, the success during August-September is higher.
Inarching : The rootstock used for propagating jamun is the jamun seedlings. For raising the rootstock, seeds are collected from healthy, vigorously growing and high yielding jamun trees. Seedlings are raised either in bed or in pots singly. In the month of June-July one or two year old rootstocks are inarched with the matching thickness of scion. Rootstocks are watered if necessary till the grafts are separated from the parent tree. The union will complete in a period of about six weeks.
Veneer grafting : Veneer grafting gives 31 per cent success when one year old seedlings are used as rootstocks. The shoots are taken from spring flush and the method is employed in the month of July.
Planting Operation :
Jamun can be transplanted during spring (February-March) or during monsoon (August-September). However, the later season of planting is considered better because the plants easily get established during the rainy season. The plants are transplanted with earth ball and are given irrigation till they get established. The size of the pit should be 1 * 1 * 1 m and these should be filled with a mixture of surface soil, silt and well rotten farmyard manure. The jamun is planted at the distance of 10 - 12 metres in square system, thus accommodates 105 - 75 plants per hectare.
Flowering and Fruiting :
The flowering in jamun starts in the first week of March and continues up to the middle of April. The trees are in full bloom in the second week of April. The inflorescence in jamun is generally borne in the axils of leaves on branchlet. The flowers are hermaphrodite, light yellow in colour. The maximum anthesis and dehiscence were recorded between 10 A.M. and 12 Noon. The pollen fertility was higher in the beginning of the season. The maximum receptivity of stigma was observed one day after anthesis.
Jamun is a cross-pollinated fruit. The pollination is done by honeybees, house flies and wind. The maximum fruit set i.e. 32.6 - 36.0% was obtained when pollination was done one day after anthesis. Thereafter, a sharp decline was observed in fruit set.
Three distinct phases of fruit growth in jamun are recorded. During the first phase (15 - 52 days after fruit set), the rate of growth was slow. In the second phase (52 - 58 days after fruit set), the rate of development was quite rapid and the third and last phase (58 - 60 days after fruit set) comprised comparatively slow growth with little addition of the fruit weight. The lenght and diameter of fruit showed a continues increase with advancement of maturity. The colour of jamun fruit changed from dark green at fruit set to light reddish colour at partial ripening and dark or bright purple at full ripe stage. The fruit took 63 days for complete ripening from fruit set. The ripe jamun had 76 per cent edible portion and 3 : 1 : 1 pulp to seed ratio. TSS and sugars followed an increasing trend, while tannin content followed a decreasing trend during growth and development.
Orchard Cultural Practices
Irrigation :
During the initial year, the jamun plants required 8 - 10 irrigations in a year while bearing trees (full grown) required 4 - 6 irrigations during the summer months of May and June when fruits ripen. In the remaining period of the year, irrigation may be given when there are no rains or dry spell persists. During winter month, irrigation proves useful as it protects the plants from frost injury.
Intercropping :
To supplement the income from pre-bearing period of jamun, intercropping should be practised judiciously. Intercropping also improved fertility of the soil. Fruit crops like peach, pulm, guava, kinnow, kagzi lime, phalsa and papaya can be grown as filler trees. Such filler trees can be uprooted when the jamun trees starts bearing commercial crop. The leguminous crop like gram, peas, moong and mash can be grown successfully. In addition, intercrops of vegetables near established market may be taken with cauliflower, cabbage, knol, khol, radish, brinjal, turnip, carrot etc.
Manuring and Fertilization :
During the pre-bearing period of jamun, a dose of 20 kg well rotten farmyard manure should be applied. To the bearing tree 80 kg FYM per tree should be supplied annually for proper growth and fruiting. Sometimes in highly fertile soils, the plants produce profuse vegetative growth and fruiting is delayed. Under such conditions, the manures should not be given and irrigation should also be given sparingly and withheld in September-October and again in February-March. This procedure will prove beneficial in fruit bud formation, flowering and fruit setting. Ringing and root pruning are also helpful.
Training and Pruning :
Jamun plants should be trained according to the modified leader system. Regular pruning is not required in jamun plants. However, in later years, the dry twigs and crossed branches are removed. While training the plant, the framework of branches is allowed to develop above 60 - 100 cm from the ground level.
Flower and Fruit Drop :
In jamun, the flower and fruit drop start just after opening of flowers and continue up to maturity. About 65 per cent flower and fruit drop in the first five weeks and since then a maxium of 19 - 21 per cent flowers and fruits drop off up to maturity. Only 12 - 15 per cent flowers reach maturity. The flower and fruit drop are found at 3 stages. The first drop takes place during bloom or shortly there after. This proves to be the heaviest drop as about 52% of the flowers drop off after 4 weeks from flowering. The second drop starts about 35 - 40 days of full bloom and apparently there is no difference between the developing and aborting fruits. The third drop takes place after 42 - 50 days of full bloom and continues till 15th July.
Control : The extent of flower and fruit drop in jamun may be reduced by two sprays of 60 ppm GA3, one at full bloom and the other 15 days after initial setting of fruit.
Harvesting and Fruit Handling :
The grafted jamun starts bearing after 6 - 7 years while the seedling one after 8 - 10 years of planting. The fruit ripen in the month of June-July. The main characteristic of ripen fruit at full size is deep purple or black colour. The jamun fruit is non-climacteric in nature. The fruit should be picked immediately when it is ripe, because it can not be retained on the tree in ripe stage. The ripe fruits are picked singly by hand and in all cases care should be taken to avoid all possible damage to fruits. For harvesting, the picker climbs the tree with bags of cotton slung on the shoulder. The fruits of jamun is generally harvested daily and sent t market on the same day. The fruit is highly perishable and can be kept in good condition for about 2 - 3 days under ordinary conditions.
The average yield of fruit from a full grown seedling jamun tree is about 80 - 100 kg and from a grafted one 60 - 70 kg per year.
The storage life of jamun fruit is 6 days at room temperature and 3 weeks at low temperature (90C and RH 85 - 90% ) when pre-cooled fruits are kept in perforated polythene bags.
Insects-pests :-
1. White-fly (Dialeurodes eugeniae)
It damages the tree in all parts of India. Sometimes the fruits of jamun get wormy due to attack of fruit fly. Pests can be controlled by maintaining sanitary situation in the orchard. Pick up the affected fruits and burry them deep in soil. The area under the tree should be dug so that the maggots in the affected fruits and the pupae hibernating in the soil may be destroyed.
2. Leaf eating caterpillar (Carea subtilis)
It is reported to damage the plant in South India at Coimbatore. The insect infest the leaves and may defoliate the trees. The pest can be controlled by spraying 625 ml Roger in 500 litres of water.
3. Squirrels, Parrots, Crows and Birds
The jamun fruits are also damaged by these squirrels, parrots, crows and birds. For keeping them away, beating of drum or flinging small dry earthern balls through a sling is useful.
Diseases :-
Leaf spot and fruit rot
The disease caused due to Glomerella cingulata. Affected leaf shows scattered spots, light brown or reddish brown in colour. The affected fruits rot and shrivel.
The disease can be controlled with fungicide like Dithane Z - 78 at 0.02% or Bordeaux mixture (2 : 2 : 250).
