Santalum album commonly known as East Indian Sandalwood or Chandan belongs to the family Santalaceae. It is highly valuable and becoming endangered species. It is distributed all over the country and more than 90% lies in Karnataka and Tamil Nadu covering 8300 sq kms. Sandalwood plays an important role in the religious life of Indians. The essential oil obtained from this wood has occupied significant place in perfumery industries/market. Although it is available in some other countries still the Indian Sandalwood has retained its dominance over other sources because of its quality.
Sandalwood is light demanding and can be easily suppressed by faster-growing species. Cultivation of sandal in India is less attempted though the potential is high. Sandal trees freely produce seed and natural regeneration occurs both via seedlings and through root suckers after trees have been uprooted and the stump removed from the ground.
Sandalwood oil also known as fragrance oil, perfume oil, body oil. The oil has a woody, exotic smell, subtle and lingering and the colour is pale yellow to pale gold. The essential oil contains Alpha-santalol and beta-santalol amount to more than 90 % of the oil – making it very superior sandalwood oil. The main chemical components are santalol, santyl acetate and santalene (Bo Jensen, Denmark)
The price of Sandalwood in India is everyday increasing price Rs. 20,000 per tonne in 1980, Rs. 200,000 per tonne in 1990; Rs. 4000,000 per tonne in 2004 and 7500,000 per tonne in 2014. India uses all S. album domestically and export is prohibited (USDA, 1990). Export of timber from India is totally banned except for handicraft pieces of sandalwood up to 50g weight. FAO, 1984 notes that it is a priority species for in setup conservation. Since then, sandalwood oil and handicrafts have become more important. International demand for sandalwood is estimated to the 10,000 mt per year. USA and France are the two largest importers of Indian sandalwood oil. Imports into the Middle are also increasing.
To encourage sandalwood cultivation, the Karnataka Forests Act, Tamil Nadu Forests Act, Kerala Forests Act and Andhra Pradesh forests Act have been amended. The ownership of sandalwood trees grown on private lands now vests with the landowners. The rules governing felling, transport, conservation and disposal of sandalwood have been liberalized. Provision has been made for payment of market value to owner of sandalwood trees.
Conservation action for economically important sandalwood of India needs to be guided by an authentic knowledge base on such plant species. This website has visualized and maintained a well-designed computerized web database providing quick access to some of the most important basic information relating to S. album tree e.g. distribution, morphology, tree improvement, soils, silviculture, physiology, biotechnology, diseases and pests, chemistry and utilization, Production and export management, etc. Such a database needs to be updated to incorporate proper description of each of these valuable properties of S. album.
Red ferruginous loam is the most common soil on which sandal tree occurs, the underlying rock often is metamorphic and chiefly gneiss. It is not exacting as to the depth of the soil and is frequently found on rocky ground and on stony or gravelly soils.
Sandal requires good drainage and does not stand water logged ground. Best growth of tree is on rich fairly moist such as garden loam and well drained deep alluvium on the river banks. (Troup, 1921) Sandal grows better in slight alkaline condition soil PH Range between 6.7. To 7.5.
Sandalwood grows best between attitudes of 700 to 1100m though it may go up to 1500m and descend as low as 300m.
Regeneration has been obtained successfully by following methods.
Ø Dibbling of seeds into bushes
Ø Dibbling of seeds in pits or mounds
Ø Planting container or polybag raised seedlings in the nurseries
Dibbling of Seeds into Bushes
This method is adopted in open scrub jungles with lot of bushes. Seeds are sown during monsoon. An instrument can be made using a bamboo pole of 4 to 6 cm internal diameter and a length of 1.5 m for the purpose of sowing seeds. The septa at the nodes are removed and one end of the pole is sharpened or a hollow metal piece is attached. The pole is introduced at the base of the bush and through the hole 4 to 5 seeds are transferred to the base of the bush. Fairly good success has been achieved by this method.
Dibbling of Seeds in Pits or Mounds
The usual trench mound technique adopted in forest for other species is also adopted for sandal. But here a perennial host plant is also grown along with sandal either on the mound or in the pit.
Planting Polybag Seedlings (Raised in the Nurseries)
Pits of 50X50X50 cm3 are dug out at a spacing of 3 mt x 3 mt or 4 mt x 4 mt. Healthy sandal seedlings; preferably above 30 cm in height are planted in the pits. Miscellaneous secondary forest species as host plants are planted in the same pit or they may be planted in separate pits in a quincunx pattern. This method has proved successful in many forest areas. At the time of planting in the field a perennial host, if given, increases the growth of sandal, otherwise it shows stunted growth with pale yellow leaves and ultimately dies in about one year. Sandal has over 150 host plants, some of the good hosts being Casuarina equisetifolia, Acacia nilotica, Pongamia pinnata, Melia dubia, Wrightia tinctoria and Cassia siamea.
SANDAL WITH MANGO AS SECONDARY HOST :
Spacing : 6 mt X 3 mt (Sandal), 6 mt x 6 mt ( Mango)
Silviculture guidelines to minimize fungal attack risk to the Tropical sandalwood industry. The recommendations will as follows:
- High risk periods of high spore count in the air and what weather events cause a greater presence of spores.
- High risk periods of high spore count in the water system and what irrigation events cause a greater presence of spores.
- Methods of branch pruning – branch size, optimum length of stump, sealing of pruning, chemical spraying after pruning the plantation.
- A pruning strategy of single verses multiple stems on heartwood production. On the one hand, multiple stems may produce less heartwood oil than a single stem; however, the reduced pruning may reduce fungal attack.
- The effect of root pruning on fungal presence in sandalwood trees.
- The risk of keeping infected trees within a plantation
Heartwood Formation and Oil Content
Heartwood formation in sandal trees generally starts around 10-13 years of age, but what triggers this process has not been very well understood. Certain factors, generally relating to stress, such as gravelly dry soil, insolation, and range of elevation (500-700 m), seem to provide the right environment for the formation of heartwood, irrespective of the size of the stem after 10 years of age. The occurrence of heartwood varies. The value of heartwood is due to its oil content, and the superiority of the oil is due to the percentage of santalol.
(i) In a tree the oil content is highest in the root, next highest in the stem at ground level, and gradually tapers off towards the tip of the stem.
(ii) Similarly, there is a gradient in oil content from the core to the periphery of the heartwood in a stem.
Depending upon their age, trees can be called young or mature, although this is an empirical classification and holds good only for a particular population. The oil content and its composition may differ at the same age:
(i) Young trees (height less than 10 m, girth less than 50 cm, and heartwood diameter 0.5-2 cm) have heartwood with 0.2-2 percent oil content, which has 85 percent santalol, 5 percent acetate, and 5 percent santalenes.
(ii) Mature trees (height 15-20 m, girth 0.5-1 m, and heartwood diameter 10-20 cm) have heartwood with oil content of 2- 6.2 percent, which has over 90 percent santalol, 3-5 percent acetate, and 3 percent santalenes.
Pest and Disease
Spike disease is one of the important diseases of sandal. This disease is caused by mycoplasma-like organisms (MLO). It can occur at any stage of development of the tree. As the disease progresses, the new leaves become smaller, narrower or more pointed and fewer in number with each successive year until the new shoots give an appearance of fine spike. At the advance stage of disease the inter nodal distance on twigs becomes small, haustorial connection between the host and sandal breaks and the plant dies in about 2 to 3 years.
Spread of disease is sporadic and the disease is transmitted in nature by insect vectors. It has been found that other insect vectors in addition to Nephotettix virescens may also be responsible for transmission of disease. So far no permanent remedial measures have been prescribed for control of spike disease.
Stem borers Zeuzera coffease Nietn (red borer) Indarbela quardinotata Walker (bark-feeding caterpillar) and Aristobia octofasiculata Aurivillius (heartwood borer) are some of the pests causing considerable damage to living trees.