Abstract

Vegetative propagation by rooting stem cuttings is a simple and comparatively less expensive method for clonal multiplication of genetically superior trees. In the present investigation branch cuttings of important timber species, viz., Tectona grandis, Gmelina arborea, Haldina cordifolia, Hopea parviflora, Melia dubia and Swietenia macrophylla were tried for root induction. The study was extended to Leucaena leucocephala, Acacia mangium and Casuarina equisetifolia in view of their potential for afforestation programmes in the state. Treatments with five growth regulating substances (G R S) (indole acetic acid, IAA; indole butyric acid, IBA; naphthyl acetic acid, NAA; Coumarin, Cou and boric acid, BA) at two concentrations each (10 and 100 ppm) were given separately to find out the most effective treatment. The influence of season on rooting was studied by repeating the treatments at monthly intervals. Results indicate that all the three factors, i.e., G R S, their concentration and season, have considerable effect on induction of rooting in cuttings. Of the ten species, rooting could be obtained only in T. grandis, G. arborea, L. leucocephala, C. equisetifolia and A. mangium. A treatment of IBA 100 ppm in May was most effective for T. grandis while NAA 100 ppm in April gave best results for G. arborea. L. leucocephala was comparatively easy to root and a treatment of BA 10 ppm in September gave profuse rooting and sprouting. For root induction in sprigs of C. equisetifolia, treatment with a GRSwas essential. Maximum percentage of rooting was in November with a treatment of IBA 10 or 50 ppm; in control only callus formation was observed. In a preliminary trial with A. mangium in June, treatment of IAA 1000 ppm (quick dip) appeared promising. The possible reasons for variation in rooting potential between species and within species are discussed