UC IPM Online UC ANR home page UC IPM home page


SKIP navigation


How to Manage Pests

UC Pest Management Guidelines

Bacterial leafspot infected plants have small, irregular necrotic spots.

Cole Crops

Bacterial Leafspot

Pathogen: Pseudomonas syringae pv. maculicola

(Reviewed 6/07, updated 6/07)

In this Guideline:


Bacterial leafspot infections start as small, dark specks on leaves. As disease develops, numerous water-soaked leafspots appear. Leafspots remain small (0.125 inch or 3 mm in diameter). Older leafspots turn tan and may or may not have a purple border around them. Leafspots are visible from both top and bottom sides of leaves. Symptoms on transplants may resemble downy mildew symptoms.


Bacterial leafspot is most often seen under greenhouse conditions. Occasionally it also occurs on cauliflower in coastal valleys, but its occurrence in production fields is sporadic. The pathogen is seedborne and is splashed from plant to plant by rain and sprinkler irrigation.


Plant clean seed and disease-free transplants. Rotation away from fields where the disease has recently occurred may reduce inoculum levels in soil or infected debris. A change from sprinkler to furrow or drip irrigation may limit its spread. Cultivars vary in susceptibility.


[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Cole Crops
UC ANR Publication 3442
S. T. Koike, UC Cooperative Extension, Monterey County
K. V. Subbarao, Plant Pathology,UC Davis, Salinas

Top of page

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.