Photo Gallery of Vegetable Problems – Tomato | Mount Vernon NW Washington Research & Extension Center

General Tomato Disease and Pest Management

Diseases
Alternaria Big bud Buckeye rot	Late blight Leaf mold Curly top	Pythium rot Verticillium wilt White mold
Insect/Mite Pests
Flea beetle	Tomato hornworm	Western flower thrips
Abiotic Problems Common to Tomato
2,4-D herbicide injury Blossom end rot	Parthenocarpy in tomato fruit Physiological leaf roll	Vivipary

(Click on photo to enlarge)

General Tomato Disease and Pest Management

Bacterial canker ravages processing tomatoes, Learn how to recognize bacterial canker now to manage this disease in the future.

How to spot and stop diseases on greenhouse tomato seedlings: Stop diseases now on tomato seedlings and produce healthy transplants for the field, Mary Hausbeck, Michigan State University Extension.

Managing Perennial Weeds in Tomatoes, This Focus on Tomato webcast by Steve Weller at Purdue University summarizes different perennial weed types, shows examples of problem perennial weeds, and discusses techniques available for managing these weeds.

MSU’s Research results for bacterial canker in tomatoes, Research indicates it is best to manage canker before field planting tomatoes. Mary Hausbeck, Michigan State University Extension.

Protect tomato transplants in the greenhouse from bacterial diseases. Mary Hausbeck, Michigan State University Extension. Although some details are specific to Michigan, the general principles in this post apply to all tomato transplant production operations.

Protect tomato transplants in the greenhouse from fungal diseases. Mary Hausbeck, Michigan State University Extension. Although some details are specific to Michigan, the general principles in this post apply to all tomato transplant production operations.

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

Tomato Diseases Favored by High Tunnel Greenhouses (recorded webscast, Dec. 2013)
By Judson Reid, Extension Vegetable Specialist, Cornell University.

Diseases

Disease: Alternaria
Pathogen: Alternaria solani


Photo Source: D.A. Inglis

Online Resources:

Early Blight Management for Organic Tomato Production, eXtension.

Disease: Big bud
Pathogen: Beet leafhopper transmitted viresence agent (BLTVA), a phytoplasma, transmitted by the beet leafhopper, Circulifer tenellus
Host crops: Tomato and several other plant species, including potato.


Photo Source: Phil Hamm, Oregon State University

Online Resources:

Tomato: Tomato Big Bud, How to Manage Pests: UC Pest Management Guidelines, UC IPM Online, University of California

Virus Diseases and Disorders of Tomato: Big Bud, Vegetable MD Online, Cornell University

Disease: Buckeye rot
Pathogen: Non pathogenic disorder

Photo Source: E. J. Sorensen

Online Resources:

Disease: Curly top
Pathogen: Beet curly top virus (BCTV), vectored by the beet leafhopper Circulifer tenellus
Host crops: Numerous plant species including many vegetables such as bean, beet, carrot,eggplant, coriander, pepper, potato, tomato, and various cucurbits such as squash,cucumber, pumpkin, watermelon, etc.


Photo Source: E. J. Sorensen	Photo Source: Phil Hamm, Oregon State University


Photo Source: Krishna Mohan, University of Idaho

Online Resources:

Pacific Northwest Plant Disease Management Handbook: Tomato (Lycopersicon esculentum) – Curly Top

Tomato: Curly top (Beet curly top virus), Washington State University Hortsense

Curly Top Disease of Tomato, Plant Management Network International.

Disease: Late blight
Pathogen: Phytophthora infestans


Photo Source: D.A. Inglis	Photo Source: Matt Tregoning, Sol to Seed Farm, Carnation, WA

Online Resources:

Pacific Northwest Plant Disease Management Handbook: Tomato (Lycopersicon esculentum) – Late Blight

Organic Management of Late Blight of Potato and Tomato (Phytophthora infestans), eXtension.

Protect tomatoes in the greenhouse from late blight, Michigan State University.

Tomato: Late blight, Washington State University Hortsense

Problem: Leaf mold
Pathogen: Fulvia fulva (formerly Cladosporium fulvum)


		Very severe symptoms of leaf mold of tomato, caused by Fulvia fulva, in a hoophouse in western Washington as a result of high humidity caused by warm days and cool nights in late summer.
Photo Source: Carol Miles, Washington State University		Photo Source: Sacha Buller, Washington State University Skagit Co. Extension Master Gardener Coordinator

Online Resources:

Pacific Northwest Plant Disease Management Handbook: Greenhouse Plants, Tomato – Leaf Mold

Disease: Pythium rot
Pathogen: Pythium species

Photo Source: E. J. Sorensen

Online Resources:

Disease: Verticillium wilt
Pathogen: Verticillium species
Host crops: Numerous vegetables including many brassica vegetables (but not broccoli), cucumber, eggplant, pepper, potato, pumpkin, radish, spinach, tomato, watermelon, etc.


Photo Source: D.A. Inglis	Photo Source: Lindsey du Toit

Online Resources:

Pacific Northwest Plant Disease Management Handbook: Tomato (Lycopersicon esculentum) – Wilts {Fusarium wilt, Verticillium wilt}

Tomato: Verticillium wilt, Washington State University Hortsense

See Diseases, pests, and other problems common to many vegetables: Verticillium wilt.

Disease: White mold
Pathogen: Sclerotinia species
Host crops: Bean, various brassica vegetables, carrot, eggplant, lettuce, potato, tomato, etc.

	Tomato stem white mold mycelium and sclerotia.
Photo Source: E. J. Sorensen	Photo Source: Jenny Glass, WSU Puyallup PIDL

Online Resources:

Pacific Northwest Plant Disease Management Handbook: Tomato (Lycopersicon esculentum) – White Mold

Tomato: White mold, Washington State University Hortsense

See Diseases, pests, and other problems common to many vegetables: White mold.

Insect/Mite Pests

Common Name: Flea beetle
Latin binomial: Pictured is the western potato flea beetle, Epitrix subcrinita, but the tuber flea beetle, Epitrix tuberis, may also damage foliage.
Host crops: Eggplant, pepper, potato, and tomato.

Potato flea beetle damage on potato foliage appears as scallop-like scoops, rounded pits or shotholes originating from the underside of the potato leaf. The adult flea beetle is small (~1/16 inch long), oblong, and dark brown to bronze in color. The most distinctive feature of the flea beetle is the enlarged hind legs that provide the insect the ability to jump considerable distances when approached or disturbed.
Photo Source: Michael Bush, WSU Extension, Yakima, WA

Online Resources:

Potato Flea Beetles: Biology and Control. Washington State University Extension Bulletin 1198E.

Potato Flea Beetles. Coleoptera: Chrysomelidae Western Potato Flea Beetle Epitrix subcrinita, Tuber Flea Beetle Epitrix tuberis

Pacific Northwest Insect Management Handbook. Chapter: Irish Potatoes, Section: Flea Beetle to Grasshopper.

Vegetables: Tomato: Flea beetles. Washington State University Hortsense.

See Diseases, pests, and other problems common to many vegetables: Flea beetle.

Common name (of damaging stage): Tomato hornworm
Latin binomial: Manduca quinquemaculata
Host crops: Pepper, eggplant, potato, and tomato.

Mature tomato hornworms can reach 3 inches long. They come in various hues of green to gray, but are distinguished from other hornworms by the eight v-shaped stripes running along the length of their bodies and a black horn on their rear end. The coloration allows these large caterpillars to remain cryptic within the canopy of tomato plants. Tomato hornworm is a plant defoliator feeding on entire leaves, small stems, and even parts of immature fruit. Often this defoliation is first noticed near the end of the growing season (August or early September) when the hornworm is approaching maturity. The tomato hornworm has one generation per year and overwinters as a pupa in the soil. Adults will emerge in the spring. The tomato hornworm adult is a large (3.5 to 5.25-inch wingspan) moth known as the five-spotted hawk moth for the five pairs of orange spots on the abdomen. The adult is rarely encountered by growers and home gardeners as it tends to fly around dusk.
Photo Source: Michael Bush, WSU Extension, Yakima, WA

Online Resources:

Pacific Northwest Insect Management Handbook. Washington State Chapter: Vegetables, Section: Tomato Part2: Fleabeetle to Wireworm.

Vegetables: Tomato: Tomato hornworm. Washington State University Hortsense.

UC Pest Management Guidelines: Tomato Hornworms. UC IPM Online, University of California.

Common name (of damaging stage): 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. An immature Western flower thrip resembles the adult, but is smaller, wingless and translucent yellow in color. There may be 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. Thrips rasp (by puncturing individual surface cells and sucking cellular contents) the surface of flower and fruit tissues as they feed. Their feeding can weaken and deform flowers and reduce flower viability. The most visible damage is caused when they rasp the surface of the fruit in areas where two fruit come in contact or when a leave lies up against the fruit. This damage is cosmetic only and does not extend beneath the fruit skin.
Photo Source: Michael Bush, WSU Extension, Yakima, WA

Online Resources:

Western Flower Thrips Thysanoptera: Thripidae Frankiniella occidentalis.

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

Pacific Northwest Insect Management Handbook. Chapter: Vegetables, Section: Cucumber (garden symphylan to wireworm).

Vegetables: Bean: Thrips. Washington State University Hortsense.

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

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

Abiotic Problems Common to Tomato

Problem: 2,4-D herbicide injury

Online Resources:

2,4-D on Tomato: Postemergence. Video of injury to a tomato plant from a postemergence application of the herbicide 2,4-D. Jerry L. Hill, Ed Peachey, Larry C. Burrill, and Craig Anderson, Oregon State University.

Problem: Blossom end rot
Cause: Calcium deficiency resulting from various environmental conditions and management practices, e.g., inadequate Ca in the soil, inconsistent water as a result of alternating wet and dry periods that decrease Ca uptake by plants, and even excellent growing conditions such as a period of very bright sunshine and warm temperatures mid-season.
Crops affected: Tomato, pepper, eggplant, and various cucurbits.

Symptoms of blossom end rot on tomato fruit.	Symptoms of blossom end rot on tomato fruit.
		Blossom-end rot is a physiological disorder that first appears as a water-soaked, light brown spot on the distil end of the fruit. As the fruit matures, the spot becomes sunken, leathery, and brown to black. Secondary pathogens can infect the area, causing fruit rot. The disorder is more common on earliest maturing fruit. Blossom end rot is associated with a low concentration of calcium in developing fruit. In eastern Washington, this is often caused by excessive soil moisture fluctuations, drought stress, or excessive nitrogen fertilization. Soil surface mulches, appropriate irrigation timing and frequency, soil amendment with limestone, and foliar applications of calcium may reduce the incidence of this disorder.
Photo Source: Krishna Mohan, University of Idaho	Photo Source: Carol Miles, Washington State University	Photo Source: Mike Bush, WSU Yakima Co. Extension Educator

Online Resources:

Blossom-end-rot on Tomatoes. By M. Ophardt, 2013. WSU Extension Garden Tips.

Blossom end rot: Understanding a perennial problem. Michigan State University Extension.

Blossom-End Rot of Tomato, Pepper, and Eggplant. By Miller, S.A., R. C. Rowe, and R. M. Riedel, The Ohio State University Extension Fact Sheet HYG-3117-96.

Blossom-end Rot of Tomatoes. Oregon State University Extension Service Bulletin FS 139. By I.C. MacSwan, 2000. Oregon State University Extension Service Bulletin.

Vegetables: Tomato: Blossom-end Rot. Washington State University Hortsense.

See Diseases, pests, and other problems common to many vegetables: Blossom end rot of vegetables.

Problem: Parthenocarpy (secondary ovary formation) in tomato fruit
Cause: Various environmentally stressful conditions
Crops affected: Tomato and many other vegetables.

Photo Source: Jenny Glass, WSU Puyallup

Online Resources:

Parthenocarpy, Wikipedia

Problem: Physiological leaf roll
Cause: Various environmental conditions and management practices
Crops affected: Tomato and Potato.


Photo Source: PNW VEG members

Online Resources:

Physiological Leaf Roll of Tomato/Potato, Identification & Management of Emerging Vegetable Problems in the Pacific Northwest. Pacific Northwest Vegetable Extension Group.

Physiological Leaf Roll of Tomato, A Fact Sheet prepared by The Pacific Northwest Vegetable Extension Group

Problem: Vivipary (germination of seeds while still attached to the mother plant)
Crops affected: Solanaceaous vegetables like tomato and pepper.

This atypical tomato developed a dark discoloration just under the skin of the ripe fruit. When cut open, seeds within the tomato fruit were germinating. This physiological disorder is known as vivipary, where the seeds germinate while still in the fruit. It is suspected to be caused by plant stress such as drought, water stress, or potassium deficiency within the fruit. The fruit are still edible.

Photo Source: Michael Bush, Washington State University Extension, Yakima, WA

Online Resources:

Effect of potassium nutrition during bell pepper seed development on vivipary and endogenous levels of abscisic acid (ABA).. By Marrush, M., M. Yamaguchi and M. E. Saltveit. 1998. J. Amer. Soc. Hort. Sci. 123(5):925–930.

Physiological and Nutrient Disorders. University of Kentucky Vegetable Integrated Pest Management Program. Vegetable Manuals.

See Diseases, pests, and other problems common to many vegetables: Vivipary.