Tomato Pith Necrosis (Pseudomonas corrugata) in Field-Grown Tomatoes in Louisiana. W. P. Bond, Department of Biological Sciences, Southeastern Louisiana University, Hammond 70402. L. L. Black, Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge 70803. Plant Dis. 70:1074. Accepted for publication 22 July 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-1074f.

Pseudomonas corrugata Roberts & Scarlett was first identified as the causal agent of tomato pith necrosis in England in 1978 (2). The disease was initially recognized in the United States in 1981 and 1982 in California and Florida (1), respectively. The disease was first observed in Louisiana in field-grown tomatoes (Lycopersicon esculentum Mill. ‘Floradel’) during the spring of 1983 and has since been seen each year in several areas of the state. Diseased plants with symptoms that include elliptical dark brown to black stem and petiole lesions, stem splitting, hollow stems, and profuse adventitious root development occur scattered in tomato fields. P. corrugata, a nonfluorescent pseudomonad, was isolated consistently from diseased tissues and produced pith necrosis when injected (0.5 ml, 10⁷ cfu / ml) into 4-wk-old greenhouse-grown ‘Bonny Best’ tomato plants. Cultural, biochemical, and physiological characteristics of two Louisiana isolates of the bacterium were similar in comparative studies to those of known isolates of P. corrugata from Florida (1).