The goal of this project is to investigate the effect of bactericides in new citrus plantings, and to evaluate the effects of repeated ACP inoculation access in infected groves treated with bactericides Objective 1: Investigate efficacy of bactericide treatments for preventing new infections. This objective is necessary to determine the potential role of bactericides in an integrated pest management program for young tree protection. Objective 2. Determine the effect of bactericide application frequency on Las infection of citrus. This experiment will determine the most effective application frequency for bactericides to maximize tree health. This will inform revised recommendations for the use of antimicrobials in commercial citrus groves.Objective 3: Quantify the effect of repeated inoculation of the efficacy of bactericides. This experiment will determine whether bactericides are sufficient to overcome the pressure of repeated Las inoculation by ACP. This will inform revised recommendations for integrated pest management programs to improve use of insecticides in conjunction with bactericides in commercial citrus groves. Bactericidal treatments were applied from May 2019 through June 2020 for each objective. However, the UF/IFAS Citrus Research and Education Center (CREC) closed on March 23rd due to COVID-19, limiting our access to the center and equipment. We were able to conduct field work as of April 20th. Samples were collected from early March, May, and June in order to quantify CLas titer in leaf tissue in response to antibiotic treatments using quantitative real-time PCR analysis. Currently, citrus leaves tissue samples from January through June are being processed to analyze the CLas-infection rate for trees in objectives 1-3.ACP adult populations were assessed by tap sampling bi-weekly from May through June 2020. Preliminary results showed a low ACP population in citrus locations due to the active vector management performed by the farm manager. Therefore, no ACP adults were collected to analyze the CLas-infection rate using quantitative real-time PCR analysis. Treatments and sampling will continue through late fall 2020 for each objective. PCR analysis will resume in June. Data will be analyzed during the 3rd quarter of 2020 in order to provide an updated preliminary assessement of bactericidal effects .