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Photo Gallery of Vegetable Problems – Broccoli

General Disease Management in Broccoli


Black Leg Club root Downy mildew

Insect/Mite Pests

Western flower thrips

Abiotic Problems

Boron (B) deficiency

(Click on photo to enlarge)

General Disease Management in Broccoli

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.


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.

Photo Source: Lindsey du Toit, Washington State University.
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.

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: Club root
Pathogen: Plasmodiophora brassicae
Host crops: Broccoli, cabbagecauliflowerbrassicaceae (cruciferous) weeds, and radish.

Below-ground symptoms of clubroot.
Photo Source: Photographer – Sharon Collman, Submitted by Jenny Glass Photo Source: Lindsey du Toit


Disease: Downy mildew
Pathogen: Peronospora parasitica

Photo Source: D.A. Inglis

On-Line Resources:

Pacific Northwest Plant Disease Management Handbook: Broccoli (Brassica oleracea) – Downy Mildew {Staghead}

Broccoli, Cole crops: Downy mildew, Washington State University Hortsense

Diseases: Downy mildew, in Cole Crops and Other Brassicas: Organic Production, ATTRA – National Sustainable Agriculture Information Service, pp 12–13

Insect/Mite Pests


Common name: Western flower thrips
Latin binomial: Frankliniella occidentalis.
Host cropsBasil, Broccoli, CabbageCauliflowerCucumberOnionPotatoPumpkinSquash,Tomato and Watermelon.

Photo Source: Michael Bush, WSU Extension, Yakima, WA

On-Line Resources:

Pacific Northwest Insect Management Handbook. Chapter: Vegetables, Section: Broccoli, Cabbage, other Crucifers.

Vegetables: Broccoli, Cole crops: Thrips, Washington State University Hortsense.

Western Flower Thrips Thysanoptera: Thripidae Frankiniella occidentalis,

See Diseases, pests, and other problems common to many vegetables: Western flower thrips.

Abiotic Problems


ProblemBoron (B) deficiency
Crops affected: Most crops can develop symptoms of boron (B) deficiency. Brassica or cole crops have moderate to high B requirements. B deficient cole crops can develop cracked, corky stems, as well as petioles and midribs. Broccoli, cabbage and cauliflower stems may become hollow and discolored. Cauliflower curds may turn brown and leaves roll and curl. Cabbage heads may be smaller than normal and discolored yellow. Cauliflower is the most sensitive of cole crops to B deficiency.

Boron deficiency in broccoli can cause external corkiness and scarring of the main stem, and hollowing of the stem internally.
Photo Source: Gail Ruhl, Purdue University Plant and Pest Diagnostic Lab Photo Source: Lindsey du Toit, Washington State University

Online Resources:

Boron mobility in plants. Chapter 7 from the book Plant and Soil by Patrick H. Brown, Department of Pomology, University of California, Davis and Barry J. Shelp, Department of Horticultural
Science, University of Guelph, Guelph, Ontario.

Boron Deficiency Symptoms U.S. Borax Corp.

Boron in vegetables U.S. Borax Corp.