------------------------------------------------------ URA 2055 ---------------- Author(s) : CADET P.,THIOULOUSE J. Traitements nematicides et peuplement de nematodes parasites de la canne a sucre au Burkina Faso. I : Repousses Revue Nematol. Serial Number : 12, 1989, pp. 35-44 Key-Words : NEMATICIDES,NEMATODE COMMUNITY PARASITIC,TRIADIC ANALYSIS Abstract Triadic analysis of three ways tables provides a means for studying the effect of nematicide treatments applied on sugarcane ratoons upon nematodes populations dynamics, by taking into account the between-plots variability of nematodes numbers. Only fumigation applied before planting has markedly reduced the size of the community. The treatments applicd in ratoons next years has only a moderate effect upon nematode multiplication. For all the treatments that we have compared, the size of the community tends to increase from ratoon to ratoon. Oxamyl, carbofuran and aldicarb, employed in ratoon, modify the balance between endoparasitic populations; their application is followed by the formation of a community dominated by Meloidogyne and Pratylenchus at the end of the crop. However, on the control, after the second ratoon the populations of Pararylenchus, Hoplolaimus and Heterodera become more important than the populations of Meloidogyne and Pratylenchus. Helicotylenchus is more influenced by seasonal fluctuations than by treatments. E-Mail : thioulou@biomserv.univ-lyon1.fr Laboratoire de Biometrie, Genetique et Biologie des Populations (URA 2055) - Univ. C. Bernard LYON I - 69622 VILLEURBANNE CEDEX