ARCHITECTURE AND DEVELOPMENT OF THE OIL-PALM (ELAEIS-GUINEENSIS JACQ)ROOT-SYSTEM

The growth dynamics and architecture of the oil-palm root system are d escribed. Following a transitional juvenile phase, eight different mor phological types of roots have been distinguished according to their d evelopment pattern and state of differentiation: primary vertical and horizontal roots, secondary horizontal roots, upward growing secondary vertical roots and downward growing secondary vertical roots, superfi cial and deep tertiary roots and quaternary roots. The relative positi on of these types of roots determines a morphological and functional u nit of the root system called ''root architectural unit'' of the oil p alm. This root polymorphism enabled us to define a morphogenetic gradi ent, which reflected the oil-palm root-system ontogenesis.