ARCHITECTURAL ANALYSIS AND MODELING OF THE BRANCHING-PROCESS OF THE YOUNG OIL-PALM ROOT-SYSTEM

An architectural analysis of the root system of young oil-palm (Elaeis guineensis Jacq.) seedlings was made. In this analysis, root branchin g was modelled by a Markov chain (discrete-time, discrete-state space stochastic process). This study has been realized on radicles of young oil-palm seedlings which were considered as main axes which branch. W e defined an elementary length unit as the smallest length between two successive lateral roots. The model was based on the analysis of a se quence of events, each event being indexed by the rank of the elementa ry length unit on the main axis. An event was defined as the state of the length unit, chosen between unbranched state and three branched-st ate categories. The branching process of the oil-palm radicle was mode lled by a four-state first-order Markov chain. Consequently, the state of an elementary length unit depended only on the state of the previo us one. The Markov chain was homogeneous, i.e. the transition probabil ities did not depend on the rank of the elementary length unit. This s tudy allowed us to identify a probabilistic model of root branching wh ich was the first step in the elaboration of a stochastic model of the architecture of the oil-palm root system.