First record of tomato wilt and pith necrosis in Syria. 1-Disease symptoms, characterization of the causal organism and some conditions predisposing plant to infection
1990
Bayaa, B. | Warrak, W.
Symptoms of a new bacterial disease have been observed on tomato plants grown in some plastic houses in the vicinity of Aleppo (Syria) during March and November 1989, and caused severe yield losses. Affected plants showed retarded growth, wilting which starts from the upper part downward, chlorosis of the basal leaves which culminate upward, dark brown discoloration of the stem, on which many aerial roots were observed. External symptoms were accompanied with pith discoloration, disintegration, and hollowing. Results of isolation, pathogenicity, cultural, biochemical, biological and microscopic tests performed on the isolated organism (s), and the chronology of disease symptoms' development, both in plastic house and laboratory, revealed that the causal organism is the bacterium Pseudomonas corrugata Roberts and Scarlett. Observations indicated that high relative humidity, exaggeration in nitrogen fertilization and pruning of basal leaves are important factors predisposing plants to infection
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