Photo Gallery of Vegetable Problems – Broccoli | Mount Vernon NWREC

General Disease Management in Broccoli
Diseases
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.

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 blackleg fungus, Phoma lingam,on an infected cauliflowerseed. Note the amethyst-colored cirrhi (gelatinousmatrix) oozing from thepycnidia, which indicatesthe strain of the pathogenis virulent(able to causePhoma leaf spot or blackleg 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: Club root
Pathogen: Plasmodiophora brassicae
Host crops: Broccoli, cabbage, cauliflower, brassicaceae (cruciferous) weeds, and radish.

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

On-Line Resources:

Pacific Northwest Plant Disease Management Handbook: Broccoli (Brassica oleracea) – Clubroot

Club Root of Cabbage and Other Crucifers, Extension Bulletin 1049, Washington State University Extension.

Clubroot. Wikipedia.

Clubroot of vegetable brassicas – towards integrated control. New Zealand Institute for Crop & Food Research Ltd.

Clubroot of Crucifers. The Ohio State University Extension.

Managing Clubroot: Equipment Sanitation Guide. Canola Council of Canada

Top 10 tips from the 2013 International Clubroot Workshop. Canola Watch, Canola Council of Canada.

See Diseases, pests, and other problems common to many vegetables: Clubroot of brassica vegetables.

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 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

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

Problem: Boron (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:

http://agdev.anr.udel.edu/weeklycropupdate/?p=4782

http://customers.hbci.com/~wenonah/min-def/cauliflr.htm

http://www.ipmimages.org/browse/subimages.cfm?sub=18132

http://www.spectrumanalytic.com/support/library/ff/B_Basics.htm

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.