LARGE-SCALE VEGETATIVE PROPAGATION OF LASIOCOCCA COMBERI BY AIR LAYERING.

Lasiococca comberi (Euphorbiaceae), a threatened forest tree species of Eastern Ghats of India, has inherent problems of seed germination and seedling establishment in nature. To overcome this problem and to facilitate large-scale production of planting materials for reintroduction programmes to augment the wild populations of this threatened species, an attempt has been made to develop an efficient vegetative propagation method through air layering. Three types of auxins such as indole-3-butyric acid (IBA), indole acetic acid (IAA) and naphthalene acetic acid (NAA) in different concentrations and combinations were used to induce rooting in stems of healthy mature trees in forests during rainy season. Air-layered branches treated with 5000 ppm IBA resulted in maximum percentage of rooting (95.23 ± 7.6%), maximum number (14.50 ± 1.9) and length of roots (12.5 ± 1.0 cm), minimum days taken for root initiation (18.5 ± 0.5 days) and highest percentage of survival of air-layered propagules. The well-rooted branches were transplanted in polybags under mist house conditions for acclimatisation and hardening before field planting. The result of the present study can be useful for mass production of large-sized planting materials of this threatened species from mature trees in a relatively shorter period at a reasonable cost for reintroduction to natural habitats as a part of species recovery programme. [ABSTRACT FROM AUTHOR]