CONSERVATION AND PROPAGATION OF RED SANDERS (Pterocarpus sentetlnu« UN.)

Abstract

Red sandalwood (Red sanders) is an evergreen tree species grown under semi dry climates inwell -drained lateritic soils, in nature .The reddish and fragrant heartwood has range ofmedicinal, pharmaceutical industrial and timber value and thus economically placed in the samerange as tusk and amber. The red heartwood contains a range of constituents including santalin(santalic acid) santalol-pterocarpin, homo-pterocarpir and reported to have anti coagulant, antiinflammatory,anti -expectorant, anti pyretic, anti bacterial and anti tumor properties. Expensivenatural fabric paint is produced from the powdered heartwood. Heartwood is used in woodcarving of prestigious nature. The natural habitats of red sanders in India (the major supplier) areextensively exploited to the point of near extinction thus placing it in the red list of endangeredspecies under IUCN guidelines

The local requirement of red sanders is met partly l.y Indian suppliers while substitutes withsimilar medicinal properties (Rath kihiriya) are also being used. The population size of redsanders in Sri Lanka is limited only to a handful cf trees, which has raised from seedlingsbrought from India about 40-50 years ago, and established mainly in Matara District. As a resultof an initial survey about 17 red sanders trees in bearing stage were identified and used as thestock of mother trees for the study. Some of the mother trees were found profusely bearingamount to hundreds id seeds. Yet there is no further increase in population size indicating apractical difficulty either in seed germination or in early seedling growth.

Seeds comprise of a very hard seed coat at the centre, which has differentiated in to a sickleshaped wing around the seed. The following seed treatment i.e. removal of seed coat, overnightsoaking, chemical scarification of seed coat, GA treatment, alternate wetting and drying andstratification were tested. Alternate wetting and dryi ng seems to be the most effective amongtreatments. The rate of germination is rather low owing to number of reasons. Alternate wettingand drying for a period of about 50 days with fully mature seeds collected under the tree can berecommended to enhance germination

The use of stem cuttings and air layering with commercial hormone mixtures "Secto" and"Clonex" was tried with a view of establishing a protocol for vegetative propagation of redsanders. Air layering was practiced with hard and semi hard type shoots of the current season'sflush. Successful root formation could be observed about 8-10 weeks after layering. Uponsuccessful root formation, layers were cut off underneath the point of layering and carefullytransferred to large polythene bags filled with a potting mixtures and kept in shade for furtherroot growth. Use of semi hard wood type, 2 nodal stern cuttings with the same commercialhormonal preparations was also found effective in vegetative propagation of red sanders. Rootswere robust and vigorous in air layers compared to stern cuttings, but the rate of manipulation iscomparatively low.