Citrus disease research focuses on identifying and managing diseases that affect citrus trees, including oranges, lemons, limes, and grapefruits. These diseases can be caused by bacteria, fungi, viruses, or other pathogens, and can result in reduced fruit yield and quality, as well as tree decline and death. Research in this area often involves studying the biology of citrus pathogens, developing disease-resistant citrus varieties, and implementing effective control measures, such as the use of pesticides and cultural practices. Ultimately, the goal of citrus disease research is to protect and sustain the citrus industry by ensuring the health and productivity of citrus trees.