Anthracnose Stalk Rot of Corn
Published: 03/19/2019
Anthracnose is likely the most prevalent stalk rot in the eastern United States. Affected plants have shredded pith and die prematurely. Anthracnose also causes a distinctive blackening of the stalk rind. Initially, these areas are narrow, water-soaked lesions, but they turn very dark and shiny and can join together to form large black blotches or streaks over the growing season. Anthracnose also can cause a top dieback, where the stalk above the ear dies four to six weeks after pollination.
Anthracnose stalk rot symptoms on the interior and exterior of the stalk.
Image: A. Sisson
Stalk death above the ear can also be a symptom of anthracnose stalk rot.
Image: A. Robertson
Anthracnose disease cycle.
*Occurrence of leaf blight and stalk rot is not necessarily related despite being caused by the same pathogen. This is because resistance to leaf blight is not highly correlated with resistance to stalk rot.
The fungus overwinters in corn residue and infects plants through the roots or by spores that splash onto the stalk or are carried by insects that may introduce them into feeding wounds. Seedlings can be infected, and some plants may die before pollination. The disease usually does not appear until late in the season and occurs more severely where corn follows corn, especially in reduced tillage.
Resistance to anthracnose is available in some hybrids. If a hybrid is resistant to stalk rot, it is not necessarily resistant to the leaf blight phase. Rotation and tillage will reduce inoculum. If more than 10 to 15 percent of stalks are observed to be rotted 40 to 60 days after pollination, the field should be scheduled for earliest possible harvest.
Dark lesions on the stalk exterior from anthracnose stalk rot.
Dark lesions on the stalk exterior from anthracnose stalk rot.
Anthracnose stalk rot symptoms on the interior and exterior of the stalk.
Early symptoms of anthracnose stalk rot.
Lodging from anthracnose stalk rot.
Spore masses on the stalk above the ear sometimes observed with anthracnose stalk rot.
Stalk death above the ear can also be a symptom of anthracnose stalk rot.
Anthracnose stalk rot symptoms include interior and exterior stalk discoloration.
Anthracnose stalk rot signs include small, dark structures (setae) visible under magnification.
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.
©2023 by the Crop Protection Network. All rights reserved.
