STUDIES ON CASHEWNUT AIR-LAYERS II. THE MORPHOLOGICAL AND ANATOMICAL CHARACTERS OF ROOTS IN RELATION TO TRANSPLANTATION SHOCK AND SUBSEQUENT FIELD MORTALITY

ISHS Acta Horticulturae 108: International Cashew Symposium

STUDIES ON CASHEWNUT AIR-LAYERS II. THE MORPHOLOGICAL AND ANATOMICAL CHARACTERS OF ROOTS IN RELATION TO TRANSPLANTATION SHOCK AND SUBSEQUENT FIELD MORTALITY

Authors:

M.S. RAJEEVAN, K. SRINIVASAN

Abstract:
Air layering was known to be a successful method of vegetative propagation for cashewnut. But its large scale adoption by the cultivator is limited on account of the very high rate of mortality ranging from 50 to 70 per cent under field conditions on transplantation. Studies on morphological, physical and anatomical characters of the roots of cashew, guava and lemon air-layers were taken up in this study with the objective of identifying the factors which contribute to their mortality or survival in the field. Inadequacy of the root system of cashewnut in contrast to guava and lemon is mainfested in the low number and growth of intial roots, low specific gravity and high moisture content, poor development of mechanical tissues and low resistance to applied pressure. These factors make the roots of cashewnut air-layers extremely succulent, brittle and suceptible to easy damage at the slightest disturbance at the time of transplantation.