Effect of Plant Growth Regulators on Cuttings and Air Layering of Indian Olive (Elaeocarpus floribundus Blume)

Abstract

Indian Olive (Elaeocarpus floribundus Blume) is locally known as jalpai, a potential minor fruit crop in north-eastern parts of India. Because of the recalcitrant nature of the seed, a short period of seed viability and a hard seed coat, the present investigation was conducted to examine the rooting response of cuttings and air-layered branches of E. floribundus towards different types and doses of root-promoting plant growth regulators in combination with an auxin synergist. The cutting experiment was conducted during three planting periods, viz., mid-March, mid-July and mid-November, in a Completely Randomised Design (CRD) comprising nine treatments with three replications. Air-layering was carried out, comprising seven treatments, including a control (untreated) with three replications. Cuttings were treated with Indole-3-butyric acid (IBA) and Naphthalene acetic acid (NAA) at 1000, 2000, 4000, and 6000 ppm, where air layerings were treated with IBA and NAA solutions of 500, 1000 and 2000 ppm with p-hydroxybenzoic acid (phb) of 2000 ppm as an auxin synergist. Both the varying concentrations of IBA and NAA failed to induce growth and sprouting in the cuttings. Air layerings treated with NAA 1000 ppm+2000ppm phb and IBA 500 ppm +2000ppm phb recorded the highest 100 and 98.33% callusing per cent, respectively. Rooting response was found to be maximum 93.33 and 91.67% in IBA 500 ppm+2000 ppm phb and NAA 1000 ppm+2000 ppm phb, respectively, while minimum (60%) was recorded in the control. The present study indicates that air-layering constitutes a viable, efficient, and economically feasible method for the vegetative propagation of Elaeocarpus floribundus, particularly in taxa that are recalcitrant to propagation through conventional cuttings. The technique is straightforward, cost-effective, and readily adoptable by farmers owing to its high success rate and low mortality. Consequently, it enables the rapid multiplication of high-quality planting material within a relatively short time frame.