Effect of growth regulators and bio-inoculants on rooting and growth of vanilla stem cuttings

The investigation on rooting and growth of vanilla (Vanilla planifolia Andrews) stem cuttings was carried out under 50% shade net to find out the effect of growth regulators and bio-inoculants on rooting and growth of vanilla cuttings. There were ten treatments comprising growth regulators such as IBA and NAA @ 500 and 1000 ppm each and combination of both @ 500 ppm, and different bio-inoculants like Trichoderma harzianum, Bacillus megatherium, Pseudomonas fluorescence and Azotobacter chroococcum (each @ 2 g/polybag of size 5"× 3") along with untreated control. Bio-inoculants in general proved to be superior over growth regulators (particularly NAA), but they were on par with IBA in respect of some of the rooting and growth parameters. Trichoderma harzianum was considered to be the best treatment which resulted in better sprouting percentage, length of sprout, and number of leaves, root thickness and fresh weight of roots. These results compare well with growth regulators and control treatment. Hence, Trichoderma harzianum could be conveniently used for the commercial propagation of vanilla stem cuttings planted under 50 per cent shade net, which would be more economical and eco-friendly.