Damping Off of Vegetables

Pest Management Fact Sheet #5063

Authors: Dr. Alicyn Smart and Nathan Andrews

For information about UMaine Extension programs and resources, visit extension.umaine.edu.
Find more of our publications and books at extension.umaine.edu/publications/.

Pathogen: Many fungal genera including Alternaria, Botrytis, Fusarium, and Rhizoctonia as well as Protist genera Pythium and Phytopthera

Introduction

Damping-off is a common but highly damaging plant disease that affects seedlings at the beginning of the plant’s life cycle. This soil-borne disease infects young or germinating seedlings during unfavorable growing conditions. In Maine, this usually will be caused by cool, wet conditions both above and below the soil line. In these conditions, spores will quickly cause seedlings to rot, collapse, and die. Within days of germination, seed beds can lose hundreds or thousands of seedlings to this disease.

Host Plants

all vegetable seedlings

Symptoms and Signs

Damping off will occur very rapidly. Seeds and germinated plants may be rotted quickly and fail to emerge above ground. Emerged seedlings will begin to rot or brown on the stem or at or below the soil line, causing the plant to topple over and die. Wet lesions may be found on the stems or crowns of these plants. Depending on the pathogenic fungi causing the disease, a foliar blight may appear on the cotelydons or the true leaves.

Management

When seeding, do not stack trays after filled with soil. This can cause compaction of the soil and add stress to the plant when germinating.
Sterilize any reused materials like seedling trays by removing all the soil from the tray and submerging it in a 10% bleach solution
Add biological organisms to the soil when seeding. Examples of products are listed below.
Plant seedlings in warm soil and dry conditions.
Supply bottom heat to trays to increase soil temperature
Plant seeds shallowly in soil or seed trays
Use proper spacing of seedlings recommended during planting.
Avoid overwatering.
Avoid using fungicides if possible due to seedlings being sensitive to phytotoxicity, which may occur when pesticides are applied.

Fungicides
Active Ingredient	Application	Trade Name
Bacillus subtilis v. amyloliquefaciens	2.6 to 5.2 oz/A	Taegro ECO^OG
Coniothyrium minitans	0.75 to 1.5 oz per 1000 ft²	Contans WG^OG
cyazofamid*	3 fl oz/100-gal water	Ranman
mancozeb	8 oz/100 lb. seed	Dithane M45
propamocarb HCl*	See label for rates	Previcur Flex
Streptomyces griseoviridis	1 to 2 g/cubic yd	MycoStop^OG
Trichoderma asperellum, T. gamsii	See label for rates	Bioten^OG
Trichoderma species	See label for rates	RootShield^OG, Rootshield Plus^OG

*For Pythium and Phytopthera ONLY

You should check your local town ordinance for any pesticide restrictions before application.

References

Meadows, Inga, Sharpe, Suzette, and Michelle Henson (2017, December 6). Damping off in Flower and Vegetable Seedlings. Retrieved from North Carolina State University – Extension: https://content.ces.ncsu.edu/damping-off-in-flower-and-vegetable-seedlings

Seebold, Kenneth W., and Nicole A. Ward (2012, February). Damping-off
of Vegetables and Herbaceous Ornamentals. Retrieved from University of Kentucky – Cooperative Extension: https://plantpathology.ca.uky.edu/files/ppfs-gen-03.pdf

Moorman, Gary W (2011, April 27). Damping Off. Retrieved from Pennsylvania State University – Extension: https://extension.psu.edu/damping-off

Johnson, Michael, and Claudia Nischwitz (2014, October). Damping-off. Retrieved from Utah State University – Extension: https://utahpests.usu.edu/uppdl/files-ou/factsheet/PLP-021.pdf

Multiple Authors. Disease Control: Tomato, Greenhouse, and High Tunnel. Retrieved from New England Vegetable Management Guide: https://nevegetable.org/crops/disease-control-24

Wick, Robert L. (2013, December). Damping-Off of Bedding Plants and Vegetables. Retrieved from the University of Massachusetts, Amherst – Extension: https://ag.umass.edu/greenhouse-floriculture/fact-sheets/damping-off-of-bedding-plants-vegetables

WHEN USING PESTICIDES, ALWAYS FOLLOW LABEL DIRECTIONS!

Alicyn Smart, DPM
Plant Pathologist and Director of the Plant Disease Diagnostic Laboratory
University of Maine Cooperative Extension

Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

Call 800.287.0274 (in Maine), or 207.581.3188, for information on publications and program offerings from University of Maine Cooperative Extension, or visit extension.umaine.edu.

The University of Maine is an EEO/AA employer, and does not discriminate on the grounds of race, color, religion, sex, sexual orientation, transgender status, gender expression, national origin, citizenship status, age, disability, genetic information or veteran’s status in employment, education, and all other programs and activities. The following person has been designated to handle inquiries regarding non-discrimination policies: Director of Equal Opportunity, 101 North Stevens Hall, University of Maine, Orono, ME 04469-5754, 207.581.1226, TTY 711 (Maine Relay System).