Effect of genotype and auxin treatments on rooting response in stem cuttings of CPTs of Pongamia pinnata, a potential biodiesel legume crop

Mature stem cuttings of 10 candidate plus trees (CPTs) of Pongamia pinnata were subjected to auxin application to compare their adventitious rooting ability. Significant differences were observed for sprouting (26-86.67%) and rooting (56.67-93.33%) behaviour. Rooting after nine weeks was more than 96% from NGPP 26, 27 and 46, in IAA 1.42 mM + IBA 4.92 mM + NAA 1.34 mM and was approximately four times that of control. Auxin treatment increased number of roots (2.32) and root length (22.23 cm) but had negligible effect on the number of shoots per rooted cutting. Cuttings harvested during January showed maximum rooting while the sprouting was better during October. The interaction among auxins, genotypes and month of collection had a significant effect on root induction and differentiation.