Broccoli

Diseases

Insect/Mite Pests

• Western flower thrips

Abiotic Problems

• Boron (B) deficiency

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(Click on photo to enlarge)

General Disease Management in Broccoli

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

• Small-Scale Cost-Effective Hot Water Seed Treatment – Reduce the risk of seed-borne diseases, especially for organic Brassica growers.

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Diseases

Black leg

Disease: Black leg
Pathogens: Phoma lingam (sexual stage = Leptosphaeria maculans)
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). 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 six counties in northwestern WA and all counties east of the Cascade Mountains because of the risk of this pathogen to the brassica vegetable seed industry.

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 (Brassica and Raphanus spp.)-Black Leg.
• Black leg in Brassicaceae crops and wild crucifers: 2014 outbreak in the Willamette Valley of Oregon (pdf).
• Black Leg, Light Leaf Spot, and White Leaf Spot (pdf), Cynthia Ocamb, PhD., Plant Pathologist, OSU Extension, Associate Professor–Botany & Plant Pathology.
• Fungicides for Control of Black Leg (pdf), 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 (pdf) – 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 (pdf) (603-052-0860), Oregon Department of Agriculture.
• Management of Black Leg in Oregon on Brassica seed crops (pdf), a Clinic Close-up, Oregon State University Extension Service.
• Management of Black Leg in Oregon on Vegetable Brassica Crops and Seed Crops (pdf), a Clinic Close-up, Oregon State University Extension Service.

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Black rot

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.

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.

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Club root

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

On-Line Resources:

• Pacific Northwest Plant Disease Management Handbook: Broccoli (Brassica oleracea) – Clubroot.
• Club Root of Cabbage and Other Crucifers, Extension Bulletin 1049 (pdf), 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 (pdf). 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.

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Downy mildew

Disease: Downy mildew
Pathogen: Peronospora parasitica

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 (this link will download the PDF file), see pages 12–13.

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Insect/Mite Pests

Western flower thrips

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

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

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Abiotic Problems

Boron (B) deficiency

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.

Online Resources:

• Boron Deficiencies in Cole Crops, University of Delaware Extension.
• https://www.ipmimages.org/browse/subimages.cfm?sub=18132
• https://www.spectrumanalytic.com/support/library/ff/B_Basics.htm.
• Boron mobility in plants (pdf). 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 (pdf) U.S. Borax Corp.
• Boron in vegetables (pdf) U.S. Borax Corp.

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