Photo Gallery of Vegetable Problems
Carrot
Diseases |
||
General Carrot Disease Management |
Nematodes |
|||
Insect/Mite Pests |
|||
Parasitic Plants |
|||
Abiotic Problems Common to Carrot |
|||
(Click on photo to enlarge)
Diseases
General Carrot Disease Management
Various root rots of carrots. Dr. Caterina Saude and Dr. Mary K. Hausbeck, Department of Plant Pathology, Michigan State University, Carrot Country, Summer 2006
Disease: Bacterial blight
Pathogen: Xanthomonas hortorum pv. carotae (formerly Xanthomonas campestris pv. carotae)
Photo Source: Lindsey du Toit, Washington State University |
Close-up view of bacterial blight lesions showing watersoaking and chlorosis around the lesions. | |
Photo Source: Lindsey du Toit, Washington State University |
On-Line Resources:
Quantitative Molecular Detection of Xanthomonas hortorum pv, carotae in Carrot Seed Before and After Hot-Water Treatment. Plant Disease 97:1585–1592.
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Bacterial Leaf Blight
Pacific Northwest Vegetable Association Annual Meeting presentation: “Bacterial blight of carrot: Management and Detection” by Lindsey du Toit.
Disease: Bacterial soft rot
Pathogen: Various bacteria including Dickeya spp. and Pectobacterium spp. (formerly Erwinia spp.)
On-Line Resources:
Disease: Black root rot
Pathogen: Thielaviopsis basicola (= Chalara elegans)
Black root rot on stored carrots. |
Photo Source: Lindsey du Toit, Washington State University |
Online Resources:
Black root rot. University of Massachusetts Amherst, Agriculture & Landscape Program, Vegetable Program, Soil, Crop & Pest Management
Disease: Black rot
Pathogen: Alternaria radicina
(symptoms on crown) |
Photo Source: Pacific Northwest seed company field representative |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Black Rot
Disease: Cavity spot
Pathogen: Pythium spp. such as P. violae and P. sulcatum
Photo Source: Lindsey du Toit, Washington State University |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Cavity Spot
Disease: Cercospora leaf spot
Pathogen: Cercospora carotae
Photo Source: D.A. Inglis |
Photo Source: Lindsey du Toit, Washington State University |
Photo Source: D.A. Inglis | Photo Source: Lindsey du Toit, Washington State University |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Cercospora Leaf Blight
Carrot: Leaf spot, Washington State University
Carrot Leaf Blight, Vegetable MD Online, Cornell University
Leaf Blights or Spots of Carrot, Universion of Illinois Extension
Management of Carrot Leaf Diseases, Ontario Ministry of Agriculture, Food and Rural Affairs
Disease: Phytoplasma and spiroplasma infection (e.g., aster yellows)
Pathogen: Various types of phytoplasmas and spiroplasma, e.g., Aster yellows phytoplasma, Beet leafhopper transmitted virescence agent (BLTVA), and Spiroplasma citri
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Aster Yellows
Aster leafhoppers in carrots, Live barley near carrots when leafhoppers may be present increases the number of leafhoppers and their potential to spread aster yellows phytoplasma. Integrated Pest Management Resources, Michigan State University
Disease: Powdery mildew
Pathogen: Erysiphe heraclei
Photo Source: Lindsey du Toit |
Photo Source: Lindsey du Toit |
Photo Source: E. J. Sorensen |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Powdery Mildew
Disease: Rhizoctonia
Pathogen: Rhizoctonia solani
Online Resources:
Pathogen: Rhizoctonia crocorum (sexual stage = Helicobasidium brebissonii)
Host crops: Violet root rot has been reported on carrot, celery, fennel, parsley, and parsnip within the Umbelliferae. However, the fungus reportedly has a wide host range that includes asparagus, artichoke, alfalfa, bean, beet, cabbage, clover, dandelion, mangel, potato, rape, rhubarb, sugar beet, sweet potato, and turnip as well as numerous weed species.
Online Resources:
https://pnwhandbooks.org/plantdisease/carrot-daucus-carota-violet-root-rot
https://www.omafra.gov.on.ca/english/crops/facts/98-001.htm#Violet%20root%20rot
Disease: White mold (=Cottony rot)
Pathogen: Sclerotinia sclerotiorum
Host crops: Bean, various brassica vegetables, carrot, eggplant, lettuce, potato, tomato, etc.
Photo Source: Lindsey du Toit, Washington State University |
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) Cottony Rot
Carrot: Cottony Rot (White Mold). Howard F. Schwartz and David H. Gent, Colorado State University
See Diseases, pests, and other problems common to many vegetables: White mold.
Nematodes
Disease: Root knot
Pathogen: Meloidogyne species
Host crops: Numerous plant species, including many vegetables such as carrot, coriander, onion, potato, etc.
On-Line Resources:
Pacific Northwest Plant Disease Management Handbook: Carrot (Daucus carota) – Nematode, Root-knot
Carrot: Root-knot nematode, Washington State University Hortsense
Major Emerging Problems with Minor Meloidogyne Species. By Axel A. Elling, Washington State University, Phytopathology Review.
See Diseases, pests, and other problems common to many vegetables: Root knot
Insect/Mite Pests
Common name: Carrot rust fly
Latin binomial: Psila rosae
Host crops: Carrot, parsnip, celeriac, celery, turnip and other umbelliferous crops, including the weed, hemlock.
Feeding damage from the carrot rust fly with a larva emerging from the feeding site. |
Photo Source: Mike Derie, Washington State University |
On-Line Resources:
Vegetable crop pests-Carrot rust fly. Pacific Northwest Insect Management Handbook, Oregon State University
Carrot Rust Fly Biology & Management. Nick Andrews, Small Farms, Oregon State University
Carrot: Carrot rust fly, Use IPM (Integrated Pest Management) for successful plant problem management. Hortsense, Carrie Foss, Pesticide Education, Art Antonelli, Extension Entomology, WSU Puyallup
Managing Carrot Rust Fly - In Search of Alternatives for a Tough Customer. Dr. David Muehleisen, Andrew Bary, Dr. Craig Cogger, Dr. Carol Miles, Amanda Johnson and Dr. Marcia Ostrom, WSU, and Terry Carkner, Terry’s Berries Organic Farm, Agrichemical and Environmental News, March 2003
Intercropping in Carrots for Rust Fly Control. Carol Miles, Ph.D.,WSU Extension, Leslie Zenz, Research Assistant, Betsie DeWreede, Owner, Independence Valley Farm, and Julie Puhich, Owner, Common Ground CSA, Mount Vernon Northwestern Washington Research and Extension Center, Vegetable Research and Extension
Carrot Rust Fly - Life Cycle and Habits. Carrot Insects, Ontario Ministry of Agriculture, Food and Rural Affairs Factsheet 93-077
Carrot rust fly. Plant Health Australia Factsheet
Common name: Lygus bugs
Latin binomial: Lygus spp.
Host crops: Numerous different species of vegetables and other crops,
e.g., alfalfa, beet, cabbage, carrot, potato, spinach, Swiss chard, etc. Lygus bugs can cause different types of damage to various growth stages of different crops. They cause blackheart on celery, blasting on flower tissues, collapse of asparagus spears, decreased yields in carrot, beet, spinach, and other seed crops, etc.
On-Line Resources:
Pacific Northwest Insect Management Handbook: Carrot seed – Lygus bug
Common name: Spider mites
Latin binomial: Tetranychus spp. including twospotted spider mite (Tetranychus urticae), strawberry spider mite (Tetranychus turkestani), and Pacific spider mite (Tetranychus pacificus)
Host crops: Wide host range, including many vegetables such as bean, carrot seed crops, potato, etc.
On-Line Resources:
Carrot seed – Twospotted spider mite. PNW Insect Management Handbook, Chapter: Vegetable Seed, Section: Carrot Seed.
See Diseases, pests, and other problems common to many vegetables: Spider mites.
Common name: Wireworm
Latin binomial: Limonius spp. (including L. canus and L. californicus). Other wireworm species including Agriotes spp. and Ctenicera spp. can be pestiferous.
Host crops: Potato, onion, carrot, beet, spinach seed crops, and radish. Other crops, like corn, beans and peas can be impacted by high densities of wireworms feeding on seedlings resulting in poor crop stands.
A click beetle of the species Agriotes obscurus, the larvae of which are wireworms. | A click beetle of the species Limonius californicus, the larvae of which are wireworms. | A click beetle of the species Limonius canus, the larvae of which are wireworms. | ||
Photo Source: Tom Brown | Photo Source: Lindsey du Toit, Washington State University | Photo Source: Oregon State University – Oregon State Arthropod Collection. |
On-Line Resources:
Vegetable crop pests – Wireworm. PNW Insect Management Handbook
Wireworms. Ontario Ministry of Agriculture and Food
Managing Wireworms in Vegetable Crops. VegEdge, University of Minnesota
Wireworm Field Guide - A guide to the identification and control of wireworms, Syngenta Crop Protection Canada, Inc.
Wireworm Biology and Nonchemical Management in Potatoes in the Pacific Northwest, N. Andrews, M. Ambrosino, G. Fisher, and S.I. Rondon, Pacific Northwest Extension Publication no. PNW607
See Diseases, pests, and other problems common to many vegetables: Wireworm.
Parasitic Plants
Common name: Field dodder
Latin binomial: Cuscuta spp.
Host Crops: Bean, beet, carrot, onion, pepper, potato, tomato, and many other crops (not only vegetables)
Dodder haustoria. | Dodder coiled on carrot leaves. | Dodder on carrot. | Dodder patch. |
Photo Source: Lindsey du Toit, Washington State University |
On-Line Resources:
See Diseases, pests, and other problems common to many vegetables: Field dodder.
Abiotic Problems Common to Carrot
Problem: Split roots
Cause: Wide fluctuations in soil moisture and growth rate of carrot roots, particularly early in the growth stage. Splitting can lead to secondary bacterial infections.
Crops affected: Beet, carrot, parsnip, radish and other root crops.
Severe splitting of a carrot root. |
Photo Source: Tom Brown |
On-Line Resources:
See Root vegetables: splitting. Royal Horticultural Society
Our pages provide links to external sites for the convenience of users. WSU Extension does not manage these external sites, nor does Extension review, control, or take responsibility for the content of these sites. These external sites do not implicitly or explicitly represent official positions and policies of WSU Extension.