Technical Abstract: Farmer field schools (FFS) and other participatory approaches are useful methods for rapid delivery of agricultural technologies in resource-constrained agro-ecosystems. Cultivar selection, weekly fungicide applications and integrated disease management (IDM) based on a disease monitoring strategy were evaluated at FFS for late blight control. Farmers’ knowledge and perceptions of pest management and agronomic practices were also assessed for FFS participants and non-participants from 1999-2002. Late blight development and tuber yield varied among field schools, but cultivars had significant effects on late blight severity and yield over a range of disease management options relative to the untreated check. FFS participants and non-participants used diverse sources of pest management information, but differed significantly in their management methods and practices. Cultivar resistance and fungicides were ranked as major components of pest control by 18-85% and 7-30% of FFS participants and non-participants, respectively. Differences in knowledge of cropping practices and pest biology, causal agents, disease symptoms, factors favoring disease development, and cultural management of insects and storage pests were recorded. Participatory field experiments, access to resistant cultivars, disease management and use of various agronomic practices can greatly improve pest control and potato production at FFS.