Seed Decay and Seedling Blight of Corn
Published: 03/19/2019
Many pathogens cause seed decay and seedling blight such as Pythium, Fusarium, Diplodia, Rhizoctonia, and Penicillium spp. The first symptom may be an area of the field with poor or no stand. Decayed seeds are very soft and may be covered with fuzzy fungal growth; seeds can be difficult to find if badly rotted. Postemergence damping off appears as yellowing and wilting; seedlings soon collapse leaving only dead leaves above the soil. Nodal roots may show the same decay symptoms as seminal roots and the mesocotyl. If the nodal root system escapes decay, the plant will survive; it may be stunted or recover fully.
Favored by cool, wet soils, these diseases are more common in low-lying or poorly drained areas or in fields planted too early in spring.
Standard seed treatment fungicides on corn reduce risk of seed decay and seedling blights. Planting corn when the soil temperature is above 50°F and soil moisture is not excessive also may reduce risk.
Damping off of corn plants from seedling disease.
Image: A. Robertson
Aboveground stunting caused by Pythium infection.
Image: A. Robertson
Mesocotyl lesions on seedling corn plant.
Aboveground stunting caused by Pythium infection.
Damping off of corn plants from seedling disease.
Damping off of seedling corn plants.
Infection of mesocotyl on seedling corn plant.
Rotted seedling mesocotyl.
Poor stand can indicate seedling blight or seed decay.
Pythium seedling blight symptoms.
Rotting corn seed.
An area of the field with poor or no stand can indicate seedling blight.
Gallery Images: G. Munkvold, G. Ruhl, and A. Robertson
This publication was developed by the Crop Protection Network, a multi-state and international collaboration of university/provincial extension specialists and public/ private professionals that provides unbiased, research-based information to farmers and agricultural personnel. This information in this publication is only a guide, and the authors assume no liability for practices implemented based on this information. Reference to products in this publication is not intended to be an endorsement to the exclusion of others that may be similar. Individuals using such products assume responsibility for their use in accordance with current directions of the manufacturer.
In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident.
Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA's TARGET Center at (202) 720-2600 (voice and TTY) or contact USDA through the Federal Relay Service at (800) 877-8339. Additionally, program information may be made available in languages other than English.
To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at How to File a Program Discrimination Complaint and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: program.intake@usda.gov.
USDA is an equal opportunity provider, employer, and lender.
©2024 by the Crop Protection Network. All rights reserved.
