In a market garden soil, iprodione or vinclozolin biodegradation was accelerated following only 1 application of the respective fungicides at the recommended field dosage (750 g Al ha-1). The degradation rates reached a maximum and then stabilized after 4 and 6 successive weekly treatments respectively. Very limited cross-degradation between iprodione and vinclozolin was observed. Six-wk soil solarization reduced enhanced biodegradation in our experimental plots and in commercial lettuce fields.