Vegetative propagation and initial growth performance of Stereospermum suaveolens DC., a wild tropical tree species of medicinal value

Abstract

The present study aimed at examining the amenability of Stereospermum suaveolens DC. to vegetative propagation through rooting of leafy stem cuttings using low-cost polythene propagators. Rooting efficiencies of cuttings derived from two selected matured mother trees were studied using four different concentrations of Indole-3-butyric acid (IBA), viz. 0, 0.1, 0.2 and 0.4%. IBA applied at 40 μg per cutting (0.4% concentration) resulted in significantly higher rooting responses compared to the control (P < 0.05). Differences in the length of longest root for all the treatments were significant (P = 0.05) with cuttings treated with 0.2% IBA producing the longest root. The highest survival after 3 weeks of transference of the rooted cuttings into polythene bags was found for rooted cuttings treated with 0.2% IBA. Effects of three fertilizer treatments viz. T0 (no fertilizer), T1 (10 g of Urea + 20 g of TSP + 10 g of MOP dissolved in 1 l of water) and T2 (10 g of Urea + 20 g of TSP + 10 g of MOP dissolved in 2 l of water) on initial growth of established rooted cuttings (stecklings) of Stereospermum suaveolens in polythene bags were also measured for a period of 90 days. Stem length, collar diameter and leaf area of the stecklings increased throughout the observation period. Increments of both stem length and collar diameter were significantly higher for the stecklings treated with T2 in comparison with the control while increment of leaf area was found the highest for the stecklings treated with T1. The study clearly indicated that Stereospermum suaveolens is amenable to vegetative propagation technique using juvenile single-node leafy cuttings and the initial growth performance of the established rooted cuttings (stecklings) in polythene bags under different fertilizer treatments was satisfactory.