(Click on photo to enlarge)

On-Line Resources:

Video: Blackleg Disease and Resistance Management. Published by the Canola Council of Canada.

Pacific Northwest Plant Disease Management Handbook: Cabbage and Cauliflower (Brassica sp.)-Black Leg and Phoma Root Rot

Pacific Northwest Plant Disease Management Handbook: Seed Crop, Crucifers-Blackleg

Black leg in Brassicaceae crops and wild crucifers: 2014 outbreak in the Willamette Valley of Oregon

Black Leg, Light Leaf Spot, and White Leaf Spot, Cynthia Ocamb, PhD., Plant Pathologist, OSU Extension, Associate Professor--Botany & Plant Pathology.

Fungicides for Control of Black Leg, David Priebe, Pesticides Program, Oregon Department of Agriculture.

Addressing Blackleg in the Willamette Valley: Oregon Department of Agriculture permanent ruling released on black leg of brassicaceae in January 2015 – see the Brassica Production Districts document, and the OSDA Permanent Ruling document titled ‘Crucifer blackleg disease requirements moved into one regulation; removes same requirements from rapeseed production districts,’ below.

• Oregon Secretary of State Certificate and Order for Filing - PERMANENT ADMINISTRATIVE RULES: Crucifer blackleg disease requirements moved into one regulation; removes same requirements from rapeseed production districts.
• Brassicaceae Production Districts and Rapeseed Control Areas (603-052-0860), Oregon Department of Agriculture.

Management of Black Leg in Oregon on Brassica seed crops, a Clinic Close-up, Oregon State University Extension Service.

Management of Black Leg in Oregon on Vegetable Brassica Crops and Seed Crops, a Clinic Close-up, Oregon State University Extension Service.

Disease: Black rot
Pathogens: Xanthomonas campestris pv. campestris
Host crops: Most members of the Brassicaceae (Cruciferae) = cabbage family, including broccoli, Brussels sprouts, cabbage, canola, cauliflower, various Chinese brassica vegetables, collard, kale, mizuna, mustard, oilseed rape, oilseed turnip rape, rutabaga, turnip, etc.), Sinapis (white and yellow mustard), and Raphanus (daikon and radish). Most wild species can be infected by this pathogen. This is a quarantine disease in parts of six counties in northwestern Washington because of the risk of this pathogen to the brassica vegetable seed industry. 

Cabbage black rot symptoms of marginal chlorosis and v-shaped lesions extending into the leaf.	Cabbage stem showing blackening of the vascular tissue caused by the black rot pathogen, Xanthomonas campestris pv. campestris.	Dieback and wilting of cabbage plants following a severe outbreak of black rot.	Blackening of the veins of a cabbage leaf following inoculation with the black rot pathogen, Xanthomonas campestris pv. campestris.
Photo Source: Mike Derie, Washington State University			Photo Source: Lindsey du Toit, Washington State University

Severe blackening of the veins of a cabbage leaf infected with Xanthomonas campestris pv. campestris.	Wilting of a cabbage leaf infected with Xanthomonas campestris pv. campestris.	Symptoms of leaf spot caused by  Xanthomonas campestris pv. armoraciae (left) and X. campestris pv. raphani (right), two bacterial pathogens closely related to the black rot pathogen, X. campestris pv. campestris.
Photo Source: Lindsey du Toit, Washington State University

Online Resources:

Cabbage and Cauliflower (Brassica sp.)-Black Rot, Pacific Northwest Handbooks, a Pacific Northwest Extension Publication.

Black Rot of Crucifers, Fact Sheet, Cooperative Extension, New York State, Cornell University.

Field Scouting Guide: Black Rot of Brassicas, Growing Produce, Meister Media Worldwide’s Horticulture Group.

Managing Black Rot of Cabbage and other Crucifer Crops in Organic Farming Systems, eOrganic, eXtension Foundation (extension.org).

Brassicas, Black Rot, UMass Extension vegetable Program Fact Sheet, Center for Agriculture, Food and the Environment, College of Natural Sciences, University of Massachusetts, Amherst, MA.

On-Line Resources:

Disease: Clubroot
Pathogen: Plasmodiophora brassicae
Host crops: Broccoli, cabbage, cauliflower, brassicaceae (cruciferous) weeds, and radish.

Stunting from clubroot.	Below-ground symptoms of clubroot.
Photo Source: Lindsey du Toit

Disease: Downy mildew
Pathogens: Hyaloperonospora parasitica = Peronospora parasitica
Host crops: Most members of the Brassicaceae (Cruciferae) = cabbage family, including cabbage and cauliflower.

Downy mildew sporulation on cabbage leaves.			Sporulation of downy mildew on a cabbage seed pod in a cabbage seed crop.
Photo Source: Lindsey du Toit

On-Line Resources:

Pacific Northwest Plant Disease Management Handbook: Cabbage and Cauliflower (Brassica sp.) – Downy Mildew {Staghead}

Downy Mildew of Crucifers. Plant Pathology Fact Sheet. Florida Cooperative Extension Service.

Brassica Downy Mildew. University of Massachusetts Amherst.

See Brassicaceae: Downy Mildew.

Disease: Ring spot
Pathogen: Mycosphaerella brassicicola

Photo Source: D.A. Inglis

Insect/Mite Pests

Common name: Diamondback moth
Latin binomial: Plutella xylostella

Diamondback moth pupa with imported cabbageworm hole damage to leaves.	Diamondback moth larva on cabbage.
Photo Source: Photographer – Johnny Stark. Submitted by Jenny Glass

Common name: Imported cabbage worm
Latin binomial: Pieris rapae

Imported cabbage worm by damaged cabbage leaf.

Photo Source: Photographer – Johnny Stark Submitted by Jenny Glass

Common name: Western flower thrips
Latin binomial: Frankliniella occidentalis.
Host crops: Basil, Broccoli, Cabbage, Cauliflower, Cucumber, Onion, Potato, Pumpkin, Squash, Tomato and Watermelon.

Adult Western flower thrips are minute (less than 1/8 inch long) narrow-bodied insects that range from straw to dark yellowish-brown in color. Their four wings are very narrow and characterized by long fringed hairs.	Immature Western flower thrips resemble the adults but are smaller, wingless and translucent yellow in color. There are multiple generations per year and thrips may invade vegetable fields when alternate flowering plants dry up in the summer or when an adjacent host crop is harvested.
Photo Source: Michael Bush, WSU Extension, Yakima, WA