In Belgium, 8.3 million tons of maize plants are harvested annually from 222.000 hectares of farm land and mainly used as livestock feed (www.statbel.fgov.be, 2007). However, crop quality is often reduced by ear and stalk rot due to Fusarium spp., and their associated mycotoxins are a serious problem for human and animal health (Wilson et al., 1990; Rheeder et al., 1992; Chu & Li, 1994). A large number of Fusarium species has been associated with ear and stalks rots (Bottalico, 1998; Logrieco et al., 2002). Gibberella red ear rot and Fusarium stalk rot are caused by F. graminearum and F. culmorum respectively, often associated with many additional Fusarium species. Maize pink ear rot is caused by F. verticillioides and F. proliferatum, sometimes associated with F. subglutinans and F. sporotrichioides. Some of those Fusarium species are able to produce mycotoxins of which important amounts are often found in maize silages. Nevertheless, it is established that the physico-chemical properties existing in silages (pH, aerobiose, t °) prevent the growth of Fusarium spp. (Scudamore and Livesey, 1998). Mycotoxins are thus produced in the field. The present project supported by the Région Wallonne** aims to understand the dynamics of the various Fusarium species development during the cultural season, their biodiversity as well as their mycotoxin production. Two partners are associated with BCCMTM/MUCL: the CARAH (Centre Agronomique de Recherches Appliquées du Hainaut) and the CIPF (Centre Indépendant de Promotion Fourragère, UCL) who are in charge of field assays. The CARAH team also performed the mycotoxin detection and quantification.