Photo Gallery of Vegetable Problems – Brassicaceae (cruciferous) Weeds | Mount Vernon NWREC

General Disease Management in Cruciferous Weeds
Diseases
Black Leg	Club root	White rust

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General Disease Management in Cruciferous Weeds

Crucifer Disease Guide – A Practical Guide for Seedsmen, Growers and Agricultural Advisors. Published by Seminis Vegetable Seeds, Inc.’s Plant Health Department and Seed Health Departments.

Diseases

Disease: Black Leg
Pathogens: Phoma lingam (sexual stage = Leptosphaeria maculans)
Host crops: Most members of the Brassicaceae (Cruciferae) = cabbage family, includingbroccoli, 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). Several wild species exist that may be infected by P. lingam including Descurainia (tansymustard), Sisymbrium(hedge mustard), and Thlaspi (penny-cress). This is a quarantine disease in five counties in northwestern WA because of the risk of this pathogen to the brassica vegetable seed industry.

Black leg symptoms on a cabbage seedling grown from an infested seed lot. Note the small, black fruiting bodies (pycnidia) on the hypocotyl of the seedling. Black leg infection of the cotyledon of a cabbage seedling grown from an infested seed lot. Note the small, black fruiting bodies (pycnidia) on the cotyledon. Pycnidia of Phoma lingam on the base of the stem of a Brassica rapa plant, showing pink cirrhi oozing out of each pycnidium, containing thousands of conidia. The conidia are readily splash-dispersed.
Photo Source: Lindsey du Toit, Washington State University.

Black leg lesion at the base of the stem of an infected plant from a Brassica rapa seed crop. Note the small, black pycnidia embedded in the lesion.	Phoma leaf spot lesion with tiny, black pycnidia present in the necrotic, circular lesion, surrounded by a narrow, chlorotic (yellow) halo. Black pycnidia of the black leg fungus, Phoma lingam, on an infected cauliflower seed. Note the amethyst-colored cirrhi (gelatinous matrix) oozing from the pycnidia, which indicates the strain of the pathogen is virulent (able to cause Phoma leaf spot or black leg of brassicas)
Photo Source: Cynthia Ocamb, Oregon State University.	Photo Source: Lindsey du Toit, Washington State University.

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 (Brassicasp.)-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: Clubroot of brassica vegetables
Pathogen: Plasmodiophora brassicae
Host crops: Broccoli, cabbage, cauliflower, brassicaceae (cruciferous) weeds, and radish.