April 2019�The objectives for this proposal are 1) Conduct field trials of new products and fungicide programs for PFD management as well as validation trials for the Citrus Advisory System (CAS); 2) Investigate the reasons for the movement of Postbloom fruit drop (PFD) to new areas and recent major outbreaks; 3) Evaluate methods for initial inoculum reduction on leaves so that early fungicide applications could be more effective and identify the constituents of the flower extracts using �omics� techniques.�Objective 1 was covered by project 16-010C and activities are reported there.�Contact has been made with the USDA to start on the experiments with the wind tunnel that is located at the ARS facilities in Ft. Pierce.� Unfortunately, we have not already started because authorizations were delayed by the federal government shut down. The paperwork to get the permissions has been filed and we are waiting for finalization on that front.In the meantime, work on modelling of leaf wetness to better predict PFD outbreaks in Florida has been started.� Five FAWN weather stations were selected for this work and are equiped with leaf wetness sensors.� The recorded data was compared to the output of four leaf wetness estimation models, singly and in combination.� The most accurate models were considered for modifying the citrus advisory system (CAS).� Further analysis to look at the number of recommended sprays and model accuracy are planned.�Experiments to assess the effect of available fungicides on the secondary conidiation of C. acutatum on citrus leaves.� In the intial experiment, pyraclostrobin was used and no difference was seen in the secondary conidiation regardless if sugar or water were used for stimulation of conidia.� In subsequent experiments, ferbam was used instead.� To stimulate sporulation, leaves were exposed to sterile water or 2.5% sucrose solutions with or without ferbam.� Once the treatments were complete, the leaves were coated with nail polish and the conidia and appressoria stripped from the leaf surface and counted.� Ferbam affected the viability of the spores but not the number produced.� It also signficantly reduced the number of appressoria.� A similar technique will be used to evaluate the effect of flower extracts on conidiation to determine whchi extracts to investigate.�Flowers were collected and extracted using water, methanol and ethyl acetate. The yields of all the extracts have been calculated as the future reference. All the extracts have been dried for testing their antifungal effects. Once we receive the antifungal effects of the extracts, we will start the composition analyses.��