Citrus fruits are susceptible to a serious fungal disease called black spot that prevents them from being exported to certain countries. This study tested neem oil, a natural plant extract, as a replacement for chemical fungicides currently used to clean citrus fruits. The researchers found that neem oil was just as effective as the standard copper-based treatments at killing the fungus and preventing the disease, and it worked by breaking down the fungus cell membranes. This natural alternative could help farmers and fruit companies maintain food safety while using more eco-friendly solutions.