​Effect of Plant Growth Regulators on Rooting of Avocado (Persea americana Mill.) Cuttings in Sikkim

Abstract

Background: Avocado (Persea americana Mill.) family, Lauraceae, sub-tropical evergreen tree, which is very nutritious fruit having large oil fraction which is one of the unique features and has good medicinal properties. The vegetative propagation of avocado has become increasingly important to produce a large amount of planting material. Methods: The present study was conducted in the research field at the Department of Horticulture, Sikkim University, Gangtok during 2016-2017 to evaluate the effect of different concentration plant growth regulators on the rooting of two cultivars. Hass and Fuerte Avocado (Persea americana Mill.) cuttings were investigated at the mist chamber. The experiment was laid in a completely randomized design for avocado cuttings of cvs. Hass and Fuerte with eighteen treatments comprising of different concentrations of IBA (control, 200 ppm, 400 ppm, 800 ppm, 1000 ppm) and NAA (control, 200 ppm, 400 ppm, 800 ppm, 1000 ppm). In all the treatments the cuttings were dipped in the plant growth regulators for 10 seconds. Rooting medium for planting the avocado cutting used was fine coarse vermiculite 80%, soil 10% and well rotten cow dung manure 10% in the ratio of 8:1:1 respectively for all the treatments. Result: In general, the results showed a significant increase for root initiation under treatment (IBA 800 ppm + Fuerte) followed by (IBA 400 ppm + Fuerte) which took 105.67 days for root initiation as compared to control at 5% level of significance. The avocado cuttings exhibited significant results for root initiation was 99.33 days which was recorded under treatment IBA 800 ppm + Fuerte as compared to treatment Fuerte (control) which was 121 days observed in root initiation. The maximum number of 14.05 roots at the time of transplanting in cuttings under treatment IBA 400 ppm + Fuerte and minimum was 2.00, 2.11, 2.22, 2.66 and 2.89 observed in treatment control + Hass, NAA 200 ppm + Hass, IBA 1000 ppm + Hass, IBA 200 ppm + Hass and IBA 400 ppm + Hass respectively. The maximum length of 1.53 cm root at the time of transplanting was found with treatment IBA 400 ppm + Fuerte and the minimum was 0.17 cm observed in treatment Hass (control). The rooting 72.22 percentage at the time of transplanting in cuttings was observed treatment IBA 400 ppm + Fuerte and minimum was 11.11 percentage observed in Hass (control). Fuerte with IBA 400 ppm was better in rooting capacity as compared to others.