Root diseases of the rubber tree (Hevea Brasiliensis) due to Rigidoporus lignosus (Klotzsch) Imaz. and Phellinus noxius (Corner) G.H. Cunn spread along planting lines and cause serious damage. Various control methods exist. A mathematical model was developed which allows the influence of their various parameters on the dynamics of an epidemic to be evaluated. The health status of the trees on a planting line was considered as a Markov process. The model parameters were given a biological interpretation and estimated using the results of an epidemiological survey carried out in Côte d'Ivoire from 1977 to 1984. Hypotheses of influence of dead trees before the survey, stationarity of secondary infection, and development of initial infection were tested. By simulation of the main model, the parameters were linked to percentages of infected trees on each inspection and of healthy trees at the end of the epidemic, thereby allowing the effects of the control methods to be evaluated according to their nature, efficiency, and mode of application. FOR. SCI. 39(1):41-54.