Standardization of propagation method of custard apple by air layering: Standardization of air layering in custard apple

Abstract

An experiment was carried out at instructional cum research farm, Department of Horticulture, BNCA, AAU, Biswanath Chariali during 2018-2019 to standardize the propagation method of custard apple (Annona reticulata) by air layering. The experiment was laid out in a completely randomized design with four treatments of air layering viz., Pre-conditioned with 30 days of girdling (T1), Pre-conditioned with 30 days of etiolation (T2), Pre-conditioned with 30 days of girdling +etiolation (T3) and Control i.e. Air layering without pre-conditioning (T4) with three replications and all these treatments were applied at monthly interval from March to August, 2018. Among the treatments, T2 recorded highest percentage of success of layering (62.37%), required minimum days for separation of layers from mother plant (53.02 days), maximum numbers of primary roots per layer (4.76), numbers of secondary roots per layer (12.49), longest primary root after detachment from mother plant (6.71 cm), percentage of survivability (89.05%), number of new shoots per layer at 30 days after planting (2.21), number of new shoots per layer at 60 days after planting (2.78) and number of new shoots per layer at 90 days after planting (3.09). On an average, air layering done in August (S6) produced highest percentage of success (61.44%), minimum days for separation of layers from mother plant (51.40), numbers of primary roots per layer (5.35), numbers of new shoots per layer at 30 days (2.27), 60 days (2.75) and at 90 days (3.12) after planting in poly bags. Among the treatment combinations, T2S6 (layering done in the month of August pre-conditioned with etiolation) recorded significantly highest percentage of success of layering (71.55%), required shortest days for separation of layers from mother plant (48.10 days), number of new shoots per layer at 30 days (2.67) and 90 days (3.75) after planting in polybags.