Evaluation of new postharvest treatments to reduce postharvest decays in packinghouses

We continue to evaluate new fungicides including natamycin (BioSpectra) and propiconazole (Mentor) that are promising for the control of postharvest diseases of citrus especially sour rot (the latter fungicide was registered in Japan with an MRL and FAT as of July 2018). Natamycin has a broad spectrum of activity, low resistance potential, and it is exempt from tolerance in the US. This fungicide currently does not have MRLs or FATs in other countries. New fungicides are being developed as numbered compounds, and we are characterizing EXP-19 for postharvest use on citrus. With increasing new regulations on older currently registered fungicides, new fungicides need to be evaluated to ensure alternatives are available for the industry in the future. Therefore, we continue to evaluate these fungicides in commercial packinghouse trials and cooperate with service companies and packinghouses in the monitoring for fungicide resistance. To maintain the availability of fungicide drench applications, we are evaluating new sanitation strategies for fungicide solutions to meet FSMA regulations. New organic acid sanitizers are being registered in California based on our efficacy data.