Cropping system is an essential aspect to take into account to manage blast disease (caused by the fungus Magnaporthe oryzae ). In addition to the selection of resistant cultiv ars, studies report opportunities to limit blast incidence by ma naging mineral amendment (N, Si, P, etc.), cultivar mixtures or other cropping system adaptati ons. In Madagascar, rice is the staple crop and food. Farmers traditionally grow irrigated or r ainfed lowland rice wherever possible. In the mid-1980s, CIRAD and FOFIFA launched a research program for the highlands to extend upland rice growing areas in high elevation areas o f the tropics. This program was consolidated with research on cropping practices th at ensure the sustainability of upland rice based cropping systems in this poor and fragile env ironment. New varieties where obtained, adapted for rainfed cropping up to 1800 m altitude (Dzido et al., 2004). However, farmers had to face attacks of blast disease. Due to the sm all genetic basis of these varieties, the fungus quickly overcame resistant or tolerant lines selected by breeders.