During the spring of 2004 and 2005, angular leaf spot was observed on cucumber (Cucumis sativus L.) in some areas of Kurdistan Province in Iran for the first time. Disease incidence in affected fields was approximately 100%. Symptoms were initially small, round or irregular, water-soaked spots on leaves ranging from 3 to 5 mm in diameter. These spots were limited by the leaf veins that gave them an angular appearance. Under humid conditions, tiny, white exudates formed on the undersides of the leaves and severely infected leaves turned yellow. A fluorescent pseudomonad was consistently isolated from lesions on King's medium B and characterized. Twelve strains were selected from Marivan, Dehgolan and Kamyaran in western Iran. When compared with previously identified strains, (1,2) on the basis of phenotypic, biochemical, and physiological properties, isolates were identified as Pseudomonas syringae pv. lachrymans.
