December 2015 The objectives of this proposal are 1) Determine the base line level of Guignardia citricarpa sensitivity to fungicides registered for disease control in citrus and evaluate new products for efficacy against G. citricarpa in vitro; 2) Conduct and improve implementation of spray trials for efficacy of registered products for citrus and to evaluate novel compounds in the field; 3) Optimize field evaluation of control measures through analysis of the spatiotemporal disease progress utilizing past and current field data of the outbreaks to gain knowledge on the incidence, severity and rate of the epidemic and assess the fungal population to increase the likelihood of successful field research and 4) Evaluate products and treatment conditions for postharvest control of citrus black spot. This quarter we accomplished: Objective 1: Manuscript preparation continues for the DMI fungicides. The assays with two SDHIs (fluxapyroxad and fluopyram) are on-going. Spore germination experiments with Cannonball and Vanguard are continuing. Manuscript preparation for the mycelial assays is on-going. Objective 2: Fungicide trials were initiated in 2015. Since July 2 applications were made for the fungicide trial. Data collection is underway Objective 3: Data collection is underway. Objective 4: Manuscript preparation is in progress; potentially with minor follow-up experiments to address any weaknesses in the data.