are also responsible for brown rot in several citrus species. Citrus crops are affected by several diseases caused by fungi and oomycetes. 2000) describes the etiology and epidemiology of 7 bac-terial, 16 fungal and 42 virus or virus-like diseases of citrus. Armillaria root rot Identification tip: Pale and wilted foliage, few leaves, and limb dieback are symptoms of Armillaria root rot, dry root rot, Dothiorella gummosis, and Phytophthora root rot.Look for cankers and oozing gum, cut under bark to inspect cambium and wood, and examine roots to help diagnose the cause. Fungal Diseases of Citrus Fruit and Foliage Megan Dewdney PMA 5205. Foliar Fungal Diseases to be Covered oAlternaria Brown Spot (and leaf spot of rough lemon) oGreasy spot oMelanose oScab Diseases oBlack Spot oPostbloom Fruit Drop o Pseudocercospera Fruit and Leaf Spot. Fungal diseases; Albinism Alternaria alternata = Alternaria tenuis Aspergillus flavus. Also described are diseases which are the result of pest-induced injuries, including those caused by 10 genera of Chapter. Fungal diseases. The organism responsible normally needs to be identified via laboratory diagnostic due to the microscopic nature of the organisms. Viral diseases; Citrus mosaic Satsuma dwarf-related virus: Bud union crease Virus for some combinations, otherwise genetic or unknown Citrus leaf rugose Citrus Black Spot •Caused by one fungal pathogen with two names –Guignardia citricarpa (sexual) –Phyllosticta citricarpa (asexual) •Affects all citrus varieties –Sweet oranges, grapefruit and lemons are highly susceptible •Fungus spreads in warm wet conditions in the presence of susceptible fruit when inoculum is present Diagnosis and Management of Certain Important Fungal Diseases of Citrus. Click on photos to enlarge Aboveground dieback. Oomycetes cause serious and widespread soil-borne diseases. Citrus diseases The fungus grows on dead wood in the citrus tree canopy, and can travel short distances by rain splashing or overhead watering, where it can then infect new growth and young fruit. are cultivated. What Is a Fungus? Fungal diseases of citrus showing specific symptoms can be easily diagnosed visually, while for diseases with no typical symptoms, laboratory tests are needed. Citrus Anthracnose is a fungal infection that creates round, flat tan spots that have a purple outline. edition of the Compendium of Citrus Diseases (Timmer et al. Phytophthora spp. Diseases of citrus. Diseases are normally the result of a fungal, bacterial or viral infection of the plant or fruit. A limit of symptomatic diagnosis is that some symptoms are visible only at certain times of the year or appear on organs distinct from those colonized by the pathogen. Disease causes economic loss in all the continents where Citrus spp.