VEGETATIVE PROPAGATION OF Dipterocarpus zeylanicus BY CUTIINGS

Dipterocarpus zeylanicus, an endemic tree in Sri Lanka offers great potential forbridging the gap between supply and demand of timber in the country. However,at present it has not been widely used as a plantation species. Establishment ofplantation by seeds has proved somewhat difficult due to low viability etc.Genetically uniform planting stock can be obtained rapidly through vegetativepropagation.With the above objective in mind an experiment was conducted to propagate stemcuttings of Ir.zeylanicus using a variety of rooting hormones under both mist andnon-mist conditions. In all the instances. cuttings of 15 em length and 0.3-0.4 mrnbasal diameter with two and half leaves were used. The hormone concentrationsused were, Indole Butyic Acid (lBA) 500 pprn, 1000 ppm and 1500 ppm and thecommercial hormone Sector (NAA + fungicide). Control did not have anyhormone treatment. The medium used was sand. The experiment was conductedunder two conditional environments; under a automatic mist and in a non-mistpolypropagator, a low cost alternative which was also designed to maintain a highhumidity through water manipulation.After the experimental period of 10 weeks, there was a marked differencebetween the mist and non-mist conditions in percentage survival of cuttings. Inall the treatments, % survival was higher under mist. In terms of percentagerooting, the cuttings under the non-mist propagator did not show rooting at allalthough callusing was observed in all the treatments at varying success levels.Among the rooting treatments, the highest percentage rooting (38. 10%) wasshown in the control without rooting hormones closely followed by otherhormone treatments. However, the treatment 1000 pprn of IBA showed thelowest percentage rooting (11.11 %).From these results, it can be concluded that