Influence of cutting diameter, auxin and rooting substrate on adventitious rooting from hardwood cuttings of Azadirachta indica A. Juss (Neem)

Azadirochta indica A. Juss (Neem) is a native Indian tree, well known for its medicinal features and have important to local economy. For Conservation of the genetic resources of neem, the effect of diameter (> 0.5; 0.5-1.5 and 1.5-2.5 cm), auxin, their different concentration in different rooting media on adventitious root formation (ARF) in hardwood cuttings of Azadirachta indica was studied. Three different rooting substrate (media) (sand, vermiculite and soil) were used and the experiment was established using three types of auxin (IBA, IAA and NAA) and 6 concentrations (100; 250; 500; 750; 1,000 and 1,500 mg L-1). Significant effects of cuttings diameter, auxin, their concentration and rooting substrate on adventitious rooting from neem hardwood cuttings were observed. The rooting percentage, number of roots, root length and number of leaves were evaluated. Among the all diameter of hardwood cuttings used, 0.5-1.5 cm diameter showed maximum rooting. IBA (500 mg L-1) resulted in higher rooting percentage (80%) with 6.82 sprouts, 53.06 roots, 7.13 cm root length and 7.0 leaves per rooted hardwood cuttings, when growing in sand rooting substrate. The determination of proper rooting protocols and the use of hardwood cuttings were proved important for propagation of A. indica.