RESUMEN
In recent years, the symptoms of spot and blight diseases have become common on Assyrun plum [Cordia] leaves in Menia Governorate. Investigations were carried out to isolate and identify the causative agent[s]. Subsequent experiments were carried out on the pathology of the causative agent[s] to other plant hosts. The agents responsible for spot and blight diseases on Assyrun plum leaves were identified as Alternaria tenuissima [two isolates] and Alternaria alternata [one isolate]. Moreover, the isolated fungi infected the organs of other hosts such as the leaves of ficus, guava, pods of black eye and bean, fruits of pepper, aubergine and tomato. Infection occurred only when the plant organs were artificially injured. Under the experimental conditions of this investigation, Alternaria tenuissima [isolate 1] was more pathogenic to Assyrun plum than isolate 2 of the same fungus and Alternaria alternata