Stalk Quality Concerns Going into Harvest • 9.23.16

Kris Young

Stalk Quality Concerns Going into Harvest

view photos

As combines are making their way into corn fields, growers are noticing less than ideal plant health and intactness.  Stalk lodging is a concern since many of the plants have broken tops and stalks are brown and mushy.  Closer examination shows these plants have been infected with some form of stalk rot.  See guidelines below for information on stalk rot development, identification, scouting and management. 

Stalk Rot 101

Stalk rot typically occurs in a corn plant when some kind of stress disrupts the production of carbohydrate that is needed to fill kernels in the ear.  When the plant is no longer able to produce enough carbohydrate to fulfill kernel demand, it starts to translocate carbohydrate from the roots and stalk to satisfy the kernel demand.  As a result, roots begin to weaken and are not able to fight off root rot pathogens.  Root rot pathogens move up the stalk shutting down water and nutrient flow within the plant.  Root rot becomes stalk rot which leads to stalk cannibalization or death. 

Stalk rot can set in at any time.  We typically notice symptoms just after the R5 stage (dent).  Early symptoms of stalk rot include wilting, change from green to gray color, ear droops downward, ear becomes spongy when twisted and lesions present at the base of the stalk.  Plant eventually turns brown prematurely and the internal stalk pith disintegrates which makes the plant more susceptible to stalk breakage. 

 Likely Causes of Stalk Rot in 2016

·         Early crown and root damage stress during wet and very cool May

·         Nitrogen deficiency due to high N losses during a wet May

·         Heat stress during month of June and again in mid-July

·         Wind/hail damage from storms in June and July

·         Leaf diseases such as gray leaf spot and Southern Rust moving in July and August

·         Anthracnose top dieback expressing itself in late July and August

Stalk Rot Identification

There are many different types of stalk rot.  Weather conditions during the growing season dictate the kind of stalk rot present.  For 2016, anthracnose has been the most common stalk rot followed by diplodia, gibberella and fusarium.    

Anthracnose Stalk Rot

·         Typically starts out as anthracnose top dieback where the top 1/3rd of the plant dies back

·         Stalk lesions appear as shiny black blotches or streaks on the lower stalk

·         Internal stalk tissue may have tan to brown discoloration starting at nodes

·         Favored by extended periods of hot, cloudy and humid conditions

Diplodia Stalk Rot

·         Lower internodes become straw-brown and spongy

·         Stalk lesions appear as tiny, dark fungal specks called pycnidia that form just under the stalk surface near the base of the plant.  Pycnidia specks cannot be easily scraped off surface.

·         White fungal mycelium may appear on the stalk surface

·         Tan to brown internal stalk tissue discoloration

·         Favored by dry and warm conditions early followed by wet weather after silking 

Gibberella Stalk Rot

·         Black specks on lower stalks.  Larger than pycnidia specks and can be easily scraped on stalk surface.

·         Internal stalk tissue has a pink to red discoloration

·         Favored by dry and warm conditions early followed by wet weather after silking 

Fusarium Stalk Rot

·         White, fuzzy growth at nodes on lower stalk

·         Internal stalk tissue has a whitish-pink to salmon discoloration

·         Favored by dry and warm conditions early followed by wet weather after silking 

Scouting for Stalk Rot

By doing a quick survey in a field, a grower can determine the amount of stalk damage that is present to aid in harvest timing decisions.  By walking through the field and “pinching” the lower stalk, a grower can determine the strength of the stalks.  If the stalk crushes easily by hand, stalk rot has infected the plant.  Another good method is a simple “push” test which is done by pushing the stalks to a 45⁰ angle.  Stalks that easily kink over or fall to the ground are infected with stalk rot.  If more than 25% of the stalks are infected, early harvest should be considered to minimize harvest losses. 

Management of Stalk Rots

Nothing can be done to treat or prevent stalk rots in corn.  However, there are some general practices that can be implemented to help reduce the onset of stalk rot development.

·         Select hybrids with good resistance to stalk rot pathogens and/or high ratings for stalk strength and stay green

·         Use a plant population that matches up with the hybrid and the growing conditions.  Over-populating a hybrid with limited resources (water and nutrients) can stress a hybrid and make it susceptible to stalk rot pathogens.

·         Match a balanced fertility program with hybrid and growing environment.  For example, consider using side-dress N on fields prone to N loss and on hybrids that respond well to side-dress N.

·         Consider applying foliar fungicides to maintain plant leaf health and increase tolerance to other plant stresses

·         Schedule irrigation to minimize drought stress

A growing season full of weather extremes with warm, wet conditions during grain fill can predispose corn plants to stalk rot pathogens.  Take time to scout each field and identify which ones may develop lodging issues.  Schedule those fields for an early harvest to prevent potential harvest losses.  Have a safe and bountiful harvest!






Image 1

Anthracnose Stalk Rot

Image 2

Diplodia Stalk Rot

Image 3

Gibberella Stalk Rot

Image 4

Fusarium Stalk Rot

PRIVACY POLICY | Contact us for more information

AgriGold has drafted this document, which details how we gather and disseminate information, in an effort to demonstrate our strong commitment to online privacy. Please contact us if you have any questions about our privacy policy.

Use of Internet Protocol Address

We use your Internet protocol (IP) address for several reasons: to help diagnose problems with our server, to administer our Web site, to help identify you, and to gather broad demographic information.

Use of Registration Information

Our site's registration area requires customers to supply contact information, such as name and e-mail address, and demographic information. We use this information to send updated information to you regarding current events and the status our organization. However, users may opt out of - or opt in to these promotional e-mail messages at any time. (See Opt Out/Opt In, below.)


AgriGold features security measures on our host’s servers to protect the loss, misuse or alteration of information placed under our control.

Children's Guidelines

We do not collect or use any online contact information or identifiable off-line contact information about a child without parental consent. We do not distribute personally identifiable information about children without parental consent. We do not give children the ability to post or distribute personal information without prior consent. We do not entice children with games or contests that would encourage them to disclose personal information.

Opt Out/Opt In

AgriGold allows users to opt out of receiving e-mail from us. To opt out of our mailing list you can send e-mail to a remove mailing list. To Opt Out/Opt In, please use the Contact Us form on the site.

Correct/Update Personal Information

AgriGold allows you to change or modify your personal information by using the Contact Us form on the website.


This site contains links to other sites. AgriGold is not responsible for the content or privacy practices of these sites.

Contact Us

If you have any additional questions or concerns about our privacy policy, please contact us:

AgriGold Hybrids
5381 Akin Road
St. Francisville, IL 62460

AgriGold® and Design, AgReliant Genetics® and Design, AdvantageAcre® , We Know Corn, Corn Specialist, and Giants are trademarks and servicemarks of AgReliant Genetics, LLC.


LEGAL INFORMATION | Contact us for more information

All orders and sales are subject to the AgriGold Terms and Conditions of Sale, which include but are not limited to the Limitation of Warranty & Remedy and Agronomic Zone and Planting Year. All Terms and Conditions of Sale are subject to change from time to time without prior notice. For the most up to date Terms and Conditions of Sale, see the Producers website at

Monsanto Company is a member of Excellence Through Stewardship® (ETS). Monsanto products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with Monsanto’s Policy for Commercialization of Biotechnology-Derived Plant Products in Commodity Crops. Certain products have been approved for import into key export markets with functioning regulatory systems. Any crop or material produced from this product can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their grain handler or product purchaser to confirm their buying position for this product. Growers should refer to for any updated information on import country approvals. Excellence Through Stewardship® is a registered trademark of Biotechnology Industry Organization.

B.t. products may not yet be registered in all states. Check with your Monsanto representative for the registration status in your state.

IMPORTANT IRM INFORMATION: RIB Complete® corn blend products do not require the planting of a structured refuge except in the Cotton-Growing Area where corn earworm is a significant pest. SmartStax® RIB Complete® corn blend is not allowed to be sold for planting in the Cotton-Growing Area. See the IRM/Grower Guide for additional information. Always read and follow IRM requirements.

DroughtGard® Hybrids with RIB Complete® corn blend the refuge seed may not always contain DroughtGard® Hybrids trait.

ALWAYS READ AND FOLLOW DIRECTIONS FOR USE ON PESTICIDE LABELING. IT IS A VIOLATION OF FEDERAL AND STATE LAW to use any pesticide product other than in accordance with its labeling. NOT ALL formulations of dicamba or glyphosate are approved for in-crop use with Roundup Ready 2 Xtend® soybeans. ONLY USE FORMULATIONS THAT ARE SPECIFICALLY LABELED FOR SUCH USES AND APPROVED FOR SUCH USE IN THE STATE OF APPLICATION. XTENDIMAX® HERBICIDE WITH VAPORGRIP® TECHNOLOGY AND IN CROP USES MAY NOT BE APPROVED IN ALL STATES. Contact the U.S. EPA and your state pesticide regulatory agency with any questions about the approval status of dicamba herbicide products for in-crop use with Roundup Ready 2 Xtend® soybeans.

Roundup Ready 2 Xtend® soybeans contains genes that confer tolerance to glyphosate and dicamba. Glyphosate will kill crops that are not tolerant to glyphosate. Dicamba will kill crops that are not tolerant to dicamba. Contact your Monsanto dealer or refer to Monsanto’s Technology Use Guide for recommended weed control programs.

ALWAYS READ AND FOLLOW DIRECTIONS FOR USE ON PESTICIDE LABELING. Products with NemaStrike Technology are not registered in all states. The distribution, sale, or use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. Check with your local Monsanto dealer or representative for the product registration status in your state.

Consult bag tags for E-Z Refuge product herbicide options; only those labeled GT/LL may be sprayed with glufosinate.

Seed products with the LibertyLink® (LL) trait are resistant to the herbicide glufosinate ammonium, an alternative to glyphosate in corn, and combine high-yielding genetics with the powerful, non-selective, postemergent weed control of Liberty® herbicide for optimum yield and excellent weed control.

Agrisure® Technology incorporated into these seeds is commercialized under license from Syngenta Seeds, Inc. Herculex® Technology incorporated into these seeds is commercialized under license from Dow AgroSciences LLC.

AgReliant Genetics® and Design, Advantage Acre® and Design, AgriShield®, and AgriGold® and Design are registered trademarks of AgReliant Genetics, LLC. Agrisure®, Agrisure Artesian®, Artesian, Agrisure Duracade®, Agrisure Viptera® and E-Z Refuge® are trademarks of a Syngenta Group Company. Acceleron®, DroughtGard®, Genuity®, NemaStrike, RIB Complete and Design®, RIB Complete®, Roundup Ready 2 Technology and Design®, Roundup Ready 2 Xtend®, Roundup Ready 2 Yield®, Roundup Ready®, Roundup®, SmartStax and Design®, SmartStax®, VaporGrip®, and XtendiMax®, VT Double PRO® and VT Triple PRO® are trademarks of Monsanto Technology LLC. LibertyLink® and the Water Droplet Design® are registered trademarks of Bayer. Herculex® is a registered trademark of Dow AgroSciences LLC. Respect the Refuge and Corn Design® and Respect the Refuge® are registered trademarks of National Corn Growers Association. All other trademarks are the property of their respective owners.

©2018 AgReliant Genetics, LLC.

SEED PIRACY STATEMENT: Seed containing a patented trait can only be used to plant a single commercial crop from which seed cannot be saved and replanted. Examples of seed containing a patented trait include but are not limited to Genuity® Roundup Ready 2 Yield® soybeans, and Roundup Ready 2 Xtend® soybeans. Additional information and limitations on the use of these products are provided in the Monsanto Technology Stewardship Agreement, the Monsanto Technology Use Guide, and the Roundup Ready 2 Xtend® Soybean Technology Use Guide Supplement. U.S. patents for Monsanto technologies can be found at the following webpage: