The &quote;Diseases of Cotton&quote; projects have run since 1984 and have played a key role in monitoring the emergence and decline of cotton diseases over time, often following the adoption of new technologies.Consequently, the data gathered through these projects has helped the industry assess the effectiveness of its R&D investment in cotton breeding and integrated disease management. The research outlined in this report adds to the important long-term data set of disease severity and incidence collected throughout other Diseases of Cotton projects.In-depth molecular studies highlight previously unknown variation in some seedling pathogen populations that may explain increased seedling mortality in southern NSW. And results of long-term experiments at the Australian Cotton Research Institute continue to build a better picture of the effectiveness or otherwise of potential integrated disease management strategies over time.