International Journal of Academic Engineering Research (IJAER)   Year: 2019 | Volume: 3 | Issue: 4 | Page No.: 1-7 An Expert System for Citrus Diseases Diagnosis Mohammed Ibraheem El Kahlout, Samy S. Abu-Naser Abstract: Background: Citrus, genus of plants belonging to the rue family (Rutaceae), and yielding pulpy fruits covered with fairly thick skins. Economically important plants in this group include the lemon (C. × limon), lime (C. × aurantiifolia), sweet orange (C. × sinensis), sour orange (C. × aurantium), tangerine (C. reticulata), grapefruit (C. x paradisi), citron (C. medica), and shaddock (C. maxima)[1]. Objectives: The main goal of this expert system is to get the appropriate diagnosis of disease and the correct treatment by presenting suggestions on Citrus diseases to the user with pictures to be accurately diagnosed. Methods: in this paper the design of the proposed Expert System which was produced to help farmers in diagnosing many of the Citrus diseases such as Citrus canker, Citrus scab, Citrus tristeza disease, Gummosis, Greening or Huanglongbing, Sooty mould, Powdery mildew and Anthracnose. the proposed expert system presents an overview about Citrus diseases are given, the cause of diseases is outlined and the treatment of disease whenever possible is given out. CLIPS Object Expert System language was used for designing and implementing the proposed expert system. Results: The proposed Citrus diseases diagnosis expert system was evaluated by agricultural engineers and they were satisfied with its performance. Conclusions: The Proposed expert system is very useful for agricultural engineer, specialists in plant pathology, and researchers on Citrus plant.