This project was undertaken to improve onion yields, quality and production efficiency by integrated management of weeds, pests, and diseases and the use of a comparative analysis of grower practices. A group of growers (75 tonne club) contributed funds to this project and their practices were compared with one another as well as other producers in the area. Particular emphasis was given to disease management although a number of broader aspects of integrated crop mangement were studied. Several workshops were held to encourage accurate identification of diseases by careful microscopic examination of samples. A weather-based computer model to forecast conditions favourable to the development of downy mildew was evaluated over three seasons with very encouraging results.