Kadam is a large, tall, handsome, deciduous sometime evergreen or semi-evergreen tree, with a straight, cylindrical bole and a disciplined crown of horinzontal spreading branches which are more or less whorled. In its favourable habitat, it attains a height of about 20m with a clean bole of about 9 m and a girth of 1.5 to 2.0 m. The tree has generally a thin plank buttresses at the base. Bark is thick but smooth in young trees, becoming darker, exfoliating in longitudinal fissures in older trees. Foliage consists of 13 to 30 cm by 5 to 15 cm, elliptic- oblong, shining, opposite, simple leaves. Flowers are small, orange-coloured in dense terminal globose heads, 2.5-5 cm in diameter. The fruit, a pseudocarp is a globose, orange fleshy mass of closely packed capsules each containing a number of minute, angular seeds.

Distribution

It is atree of Indo-Malayan region. It occurs in the sub himalayan tract from Nepal eastwards, extending through West Bengal and Assam into Burma, Nepal and Srilanka, Malaysia across Indonesia and Borneo to the Philippines and New Guinea. In the peninsular india, it is found in chota nagpur of Bihar, Raipur and Bilaspur districts of Madhya pradesh, Northern circars tract of Andhra pradesh  and the evergreen forest of Karnataka; Southwards to Trivadrum in Kerala (Anon, 1985). Outside of its native range, it is cultivated in Puerto Rico, South Africa, Australia and in Costa Rica. It is a constituent of southern tropical semi evergreen forests, secondary north Indian tropical moist deciduous forest and tropical fresh water swamp forest according to the classification by Champion & Seth (1968). It is reported to occur wild in the extreme eastern part of haldwani division though rarely, growing on moist or swampy ground bordering streams (osmaston, 1927). It also occurs in the tropical semi-evergreen and evergreen forest upto an elevation of 900 m in all districts of Arunachal pradesh.

The tree is commonly cultivated in many parts of the country in gardens. In West Bengal, it has been grown in plantations for a fairly long time now. In arunchal predesh, it is grown under agro-forestry situations.

SITE FACTORS

Climate

In its natural habiat, the absolute maximum shade temperature varies from 37.5° to 47.5° and the absolute maximum from 0° to 15°C. May is the hottest and January is the coldest month of the year, the mean daily maximum and minimum temperature reaching 42.5° to 4.4°C respectively. The normal rainfall ranges from 1500 to 5000 mm, received mainly during May- September. The tree can endure dry periods lasting upto 3 months without suffering any damage.

Soils

Kadam prefers deep, moist but well-drained loamy soils of alluvial origin. Although it can tolerate a certain amount of oxygen deficiency, on stiff clayey soils, the growth is very poor. It is found growing on freshly exposed soils due to landslides etc., exposed slope and degraded soils exhibiting character of long-lived pioneer species. It also comes up in the sandy soils of Brahmaputra valley. The species is considered suitable for soil conservation, agroforestry, jhum land reclamation etc.

Phenology

The tree is leafless or nearly so in the hot season. The small orange coloured highly scented flowers in globose heads appears chiefly from May to July. The fruits ripen towards the end of rains in August to October and fall in january-february. The tree flowers and fruits at an early age, a few years old trees have been observed to flower.
Silvicultural characters

The tree is a light demander, although the young plants need protecteion against sun. The saplings, however, grown under shade become spindly in their efforts to reach the light. Once they overcome other associates and reach the light, they begin to spread out and the height growth is largely substituted by lateral spread. The seedlings are sensitive to drought and also liable to damp off with an excess of moisture in the soil. The seedlings are also very sensitive to frost, which however, is unknown in its natural habitat. Young plants are very susceptible to browsing by cattle and deer. The tree coppices vigorously. After sapling stage, the tree is quite tolerant of water-logged areas where the water inundates for 2-3 months.

Natural regeneration

Natural reproduction comes profusely under favourable conditions viz. light, shade moisture and exposed soil. The seeds being minute are washed into heaps alongwith silt, germinate enmasse but rarely survive as they are either washed away or browsed by cattle. Natural reproduction is reported to come successfully in areas previously grazed but later closed to grazing. In nature, the seedlings attain only 5-15 cm height at the end of the first season, however, onwards growth is very rapid.

Artificial regeneration

Owing to small size of seeds and seedlings, sensitiveness of the seedlings to drought, frost and excessive moisture, direct sowing is difficult to obtain and cannot be relied upon. Many failures have been recorded in the past perhaps due to use of immature or ill stored seed. The species is perhaps best raised by planting out entire seedlings with balls of earth round the root system. Air layers treated with IBA root moderately.

Seed collection and storage

The ripened fruits are orange brown in colour and usually available in August-September which can be collected from the ground and heaped under shade. The best time to collect seed is middle to latter part of August. The heaped fruits can be allowed to rot for three to four days and pulp is washed off by hands in a bucket of water, seeds settled at the bottom are taken out and dried. The seed keeps well for about one year (Dent, 1948). Alternatively, ripe fruits are soaked in water for 3-4 days to allow rotting. The fruits are rubbed to form a paste like slurry, which is passed through a 0.50 mm sieve plate and shaken vigorously. The blackish paste sieved through the plate is collected into a pan and dried to extract seeds. Average dry weight of each fruit is 11.5 gm and wet weight 50 gm. Each fruit on an average yields 456 mg of pure seeds.

In the indigenious method, the dried fruits are rubbed against the rough surface of a simple device until only the receptacle remains. The device consists of a tin sheet on one side of which holes of about 0.4 cm dia are made with a nail so that uneven projections appear on the reverse side which be used for rubbing surface. After rubbing, the disintegrated fruit parts are collected and passed through a fine sieve (hole size about 0.5 mm). The sieved seeds are winnowed and 95% seed purity can be obtained. About 6 kg of dry fruits yield 1 kg of seed. Good germination is obtained by this method which shows that seeds do not get damaged by rubbing. No of seeds per kg and plants per kg in West Bengal are 9, 20,000 and 5,500 respectively (Sen Gupta, 1937). From arunchal pradesh, about 11 to 12 lac seeds are reported in a kg (Mehta, 1991).

Nuresry Technique

The sieved seeds need no pre-sowing treatment, but need special care during watering, due to minute nature of seeds. Seeds can be sown in galvanised or wooden trays filled with sand and soil and treated with fungicide. Venator (1972) recommended seed sowing on tissue paper for later transplanting.

Sowing of pulped seed gives poor germination (4.85%) as compared to pulped seed (52%). Experiments further indicate that use of soil media and watering with the help of can or fine sprayer gives maximum germination (Beniwal & Dhawan, 1991).

The seeds are better mixed with sterilized sand before sowing. They are sown in February in west Bengal at the rate of about 130 gm of seed per m2 of bed. Winter sowing is not successful. Percentage of germination is high.

The germination of A.cadamba seeds in open beds is generally difficult and at best patch germination is obtained. Therefore, plants are invariably raised in shaded beds to exclude insolation and splashing efects of rain water. Before sowing, the beds are throughly wetted and seeds are broadcast on the top taking care that seeds donot get buried in the soil, instead they are patted with hand. After sowing, watering is done with a fine rose, frequently and sparingly, according to requirements as the young seedling are sensitive to both drought and excessive moisture. Germination takes place in about three weeks. After germination shading is removed. Pricking out can be done when the seedlings are about  5 cm high after about one month in polythene bags with fungicide.

In Assam, sowing is done in May in shaded beds, germination starts about in 15 days. Seedlings are pricked out in polythene bags when they have pointed out 4 leaves. Out planting is done with 20-25 cm high seedlings.

In arunachal predesh, the seeds are soaked in water for 36 hrs, water drained and dried under shade, 100 gm of seeds mixed with equal or double amount of sand and broadcast thinly and uniformly over standard sized open beds of 1.2 m x 12 m. The beds are covered with polythene sheet, about 10 cm higher than the level of bed. About 85-95% germination is registered. The seeds can be germinated even during winter by this method (Mehta, 1991). Seedlings are pricked out in polybags in the open. The seedlings are ready for transport in about 3 months when they attain 50-60 cm height.

Planting technique The species is best raised by planting out entire seedlings or polythene bag raised seedlings during June – July at start of monsoon when they are about 4-5 months old. Rate of growth The species is very fast growing especially in the initial years. Rate of growh is very rapid in the earlier years; on an average it gives a maximum girth increment of 15 cm per annum upto the 9th year, the height increment averages 3 m per annum for the first six or eight years after which the growth becomes slower.

Pests and diseases

Young plants and coppice shoots are readily browsed by cattle, goats and deer. Among the insects, Aristobia approximator feeds on the bark, Dihammus cervinus bores in the stem and Dirades adjutaria defoliates over extensive areas.

Utilization Wood: The wood is white to creamy white, odourless, light in weight (545 kg/cum at 12% moisture content), straight-grained and medium and even textured. It is moderately strong, can be seasoned easily; but susceptible to sap- stain quickly after conversion, non durable; can be easily and completely treated with preservatives. Treated timber is quite durable. It saws and works easily under tools. Peels readily on a rotary lathe. Uses: The wood is extensively used for ceiling boards, light construction work, packing cases, planking, carving and turnery. The wood makes good veneers and plywood suitable for the manufacture of grade IV commercial plywood and tea chest plywood. It is also suitable for both match boxed and splints. Tests indicate its suitability for writing and printing paper giving 48.6% yield and over 6000 m breaking length. Brown wrapping paper can also be prepared by sulphate process. Fruits are edible. Bark and leaves are used for medicinal purposes.