Pseudomonas cichorii
bacterial blight of endive
Bacterium cichorii, Bacterium endiviae, Bacterium formosanum, Chlorobacter cichorii, Phytomonas cichorii, Phytomonas endiviae, Pseudomonas endiviae, Pseudomonas formosanum, Pseudomonas papaveris, Pseudomonas papaveris
Worldwide
AL. CA, FL, GA. HI, IL, IN, LA, MS, T. MJ, NY, NC, PA, TN, WA
2025-10-06
bacterium
Thailand
Main: celery, endives, chicory, lettuce, adzuki bean; Other: numerous in the Asteraceae and Brassicaceae families.
PSDMCI
Pseudomonas cichorii is a Gram-negative bacterium that causes leaf spot, blight, and rot on many crops such as lettuce and celery. It thrives in cool, moist environments and spreads mainly through splashing water, rain, or contaminated tools and hands. It survives on plant surfaces and debris. Transmission is favored by high humidity and overhead irrigation, leading to rapid spread and characteristic brown, water-soaked leaf lesions.
5 Known Hosts
Apium graveolens
celery
No
CABI CPC, PSDMCI-4
No references found indicating seed is a pathway.
2025-10-06 18:23:45
Chrysanthemum spp.
chrysanthemum
No
CABI CPC
No references found indicating seed is a pathway.
2025-10-06 18:23:55
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Cichorium endivia
endive
No
CABI CPC, PSDMCI-5
No references found indicating seed is a pathway.
2025-10-06 18:24:23
Daucus carota
carrot
No
CABI CPC, PSDMCI-5
No references found indicating seed is a pathway.
2025-10-06 18:25:20
Lactuca sativa
lettuce
No
PSDMCI-3, PSDMCI-4, PSDMCI-5, PSDMCI-6, PSDMCI-7, PSDMCI-8, PSDMCI-9, PSDMCI-10
For lettuce, Pseudomonas cichorii has been shown to survive on artificially inoculated seeds, but there is no experimental evidence confirming true seed transmission under natural conditions. While some sources have suggested seed as a possible pathway, others deny it. Lettuce seed is typically produced in dry climates, which are unfavorable for the pathogen’s survival, further reducing risk. Infections in production fields are more likely initiated from splashing water, irrigation, or contaminated debris rather than seed.
Yes
Seed wash
This test is commercially available, however the test has not been standardized or validated.
CABI CPC
Cultural
Seed production in dry climates are unfavorable for this pathogen. Only cultural controls in the field are effective (irrigation control, plant density, weed control, etc.)
CABI CPC, PSDMCI-9
2025-10-06 18:18:49
Ohata, K.I., Tsuchiya, Y. and Shirata, A. (1979). Difference in kinds of pathogenic bacteria causing head rot of lettuce of different cropping types. Annals of the Phytopathogenic Society of Japan 45, 333-338.
Pernezny K, Datnoff L, Sommerfeld ML, 1994. Brown stem of celery caused by Pseudomonas cichorii. Plant Disease, 78(9):917-919
Grogan RG, Misaghi IJ, Kimble KA, Greathead AS, Ririe D, Bardin R, 1977. Varnish spot, destructive disease of lettuce in California caused by Pseudomonas cichorii. Phytopathology, 67(8):957-960
Patel, N., Patel, R., Wyenandt, C. A., 2021. First report of Pseudomonas cichorii causing bacterial leaf Spot on romaine lettuce (Lactuca sativa var. longifolia) and escarole (Cichorium endivia) in New Jersey.Plant Disease, 105(12) 4150-4150.
Aysan, Y., Sahİn, S., Ulke, G., Sahİn, F., 2003. Bacterial rot of lettuce caused by Pseudomonas cichorii in Turkey.Plant Pathology, 52(6) 782.
Patterson, C.L., Grogan, R.G. and Campbell, R.N. (1986). Economically Important diseases of lettuce. Plant Disease 70, 982-987.
Bazzi, C., Piazza, C., & Mazzucchi, U. (1984). Survival in the Field of Pseudomonas cichorii (Swingle) Stapp, Causal Agent of Lettuce Varnish Spot*. Journal of Phytopathology, 111(3‐4), 251-258.
Shirata, A., Ohata, K., Serizawa, S. and Tsuchiya, Y. (1982). Relationship between the lesion development by Pseudomonas cichorii and growth stage and leaf position of lettuce and its infection mechanism. Bull. Natl. Inst. Agric. Sci. C36: 61-74
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Search the database