Adventitious Rooting of `Tommy Atkins' Mango Air Layers Induced with Naphthaleneacetic Acid

Abstract

Air layers were made in July 1988 by applying 0, 0.1, 0.5, 1.0 or 2.0% NAA in lanolin to 2- to 3-year-old girdled branches (2 cm in diameter) of 12-year-old mango trees and covering the girdles with moist sphagnum moss wrapped in Al foil. Root development after 12 weeks increased with increase in NAA rate; 93% of air layers treated with 2% NAA had stage 5 roots (primary roots >5 cm long, many thin lateral roots), while only 55% of those treated with 0.5 or 1% NAA produced such roots. Maximum root development in untreated air layers was to stage 3 (primary roots 1-5 cm long) and only 7% reached this category. When potted in Oct., survival rates were highest (>90%) for air layers with stage 5 roots and they flowered during the normal flowering period in Jan.