Effect of Different Auxin Concentrations on Rooting of Bougainvillea

The present study was conducted to evaluate the effect of different concentrations of Indole- 3 Butyric Acid (IBA) on the rooting and sprouting performance of Bougainvillea cuttings. The cuttings were treated with different IBA concentrations. The treatments were T1 (Distilled water), T2 (IBA 500 ppm), T3 (IBA 1000 ppm), T4 (IBA 1500 ppm), T5 (IBA 2000 ppm), T6 (IBA 2500 ppm), T7 (IBA 3000 ppm), T8 (IBA 3500 ppm) and T9 (IBA 4000 ppm). Key parameters observed were days to sprouting, number of shoots per cutting, sprouting percentage, root length and number of roots per cutting. The results revealed that IBA significantly enhanced rooting and sprouting compared to untreated controls. Among all treatments T6 (IBA 2500ppm) and T5 (IBA 2000ppm) were found to be the most effective, resulting in earlier rooting, increased shoot formation, higher sprouting percentage, longer roots, and more roots per cutting. Higher concentrations above 3000 ppm showed reduced effectiveness, likely due to auxin toxicity. This study concludes that moderate IBA concentrations (2000–2500 ppm) are optimal for the successful propagation of bougainvillea through cuttings.