Skip to main content

Causes of Early Season Purple Corn

Figure 3. Sulfur application timing trial at Geneseo, IL in 2021
Figure 1.
  • There are a few situations that can cause leaf purpling such as hybrid genetics or nutrient deficiency.

  • Yield loss due to leaf purpling is mostly dependent upon the cause behind the symptoms which can be compounded with other environmental factors.

Purpling of corn leaves is generally a result of the inability of a corn plant to take up adequate quantities of phosphorous OR due to the presence of unique gene(s) in specific hybrids that trigger production of reddish-purple anthocyanin pigments in young corn plant tissue (Figure 1). Optimal daily growing conditions normally result in production of high concentrations of sugar photosynthates within leaves. Typically, sugars would be metabolized overnight and redistributed to other parts of the developing roots and stems. Cool night temperatures or other biotic/abiotic stressors that inhibit root development can concentrate sugar levels in leaves. It is believed that since anthocyanin occurs in the form of a sugar, concentrations of other sugars can further promote anthocyanin production and cause excessive purpling.

Figure 2. Sulfur application timing trial at Geneseo, IL in 2021
Figure 2. “Purple corn syndrome” from the accumulation of anthocyanin in the leaves.

Hybrid Specific Response

Most corn hybrids contain one or more genes responsible for anthocyanin pigment production which causes purpling of leaf tissue (Figure 2). Hybrids containing multiple cold sensitive anthocyanin genes can be more prone to leaf purpling when soil and air temperatures are low during early vegetative stages.1 Hybrids containing multiple genes responsible for purpling can also be more visible than other hybrids growing under the same field conditions. As affected corn plants begin to transition from small seminal/radicle root systems to larger and rapid growing nodal root systems, they are better able to reallocate sugars from leaf tissue to roots and begin to #06936E up. Purpling caused by pigment producing genes usually occur uniformly across fields and only in specific hybrids, making it easy to distinguish from other causes.

Root Inhibition and Phosphorous Availability Influence on Leaf Purpling

Although some hybrids are more prone than others to leaf purpling at early growth stages, it can be a common symptom in any hybrid when the plants are unable to take up enough phosphorous (P). Although purpling of leaves is a symptom of low soil phosphorous levels, it can also be an indication that the plant is having difficulty extracting nutrients from soil with sufficient P levels due to other reasons. Purpling of leaves when soil phosphorous levels are sufficient is usually the result of one or more factors that slowed or stopped root development. There are a variety of environmental, management and pest related reasons that can impede root growth in the early vegetative stages, resulting in leaf purpling. Applying additional phosphorous to purple corn when soil test values are adequate will not likely result in additional yield.

Leaf Purpling Influence on Yield Potential

Yield loss due to leaf purpling is mostly dependent upon the driving cause behind the symptoms. Stress such as cool temperatures or wet soil conditions that result in slowed root development may be temporary, and as conditions improve, plants grow out of symptoms with little to no yield penalty. More persistent stress from things like compaction or herbicide injury may persist longer into the growing season and have potentially larger impacts on yield potential, depending on the original cause. Purpling caused by insufficient soil P levels can result in significant yield penalties and should be addressed with future nutrient management plans. Hybrids that are more prone to purpling will usually grow out of symptoms quickly as temperatures warm and nodal root systems begin to develop with little to no influence on yield potential.


1 Christie, P.J., Alfenito, M.R., and Walbot, V. (1994). lmpact of low- temperature stress on general phenylpropanoid and anthocyanin pathways: Enhancement of transcript abundance and anthocyanin pigmentation in maize seedlings. Planta 194: 541-549.

Visit Join the conversation online – connect with us at

To unsubscribe from this email list, click here.Provide your first name, last name, email address and the email address that sent the message.

Visit to view Syngenta’s Privacy Policy.

Please do not modify or alter the content of this message without prior, written approval from Syngenta.

Product performance assumes disease presence. Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace. Syngenta hereby disclaims any liability for third-party websites referenced herein.

© 2024 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your local extension service to ensure registration status. AAtrex 4L, AAtrex Nine-O, Acuron, Agri-Flex, Agri-Mek 0.15 EC, Agri-Mek SC, Avicta 500FS, Avicta Complete Beans 500, Avicta Complete Corn 250, Avicta Duo Corn, Avicta Duo 250 Corn, Avicta Duo COT202, Avicta Duo Cotton, Besiege, Bicep II Magnum, Bicep II Magnum FC, Bicep Lite II Magnum, Callisto Xtra, Denim, Endigo ZC, Endigo ZCX, Epi-Mek 0.15EC, Expert, Force, Force 3G, Force CS, Force 6.5G, Force Evo, Gramoxone SL 2.0, Gramoxone SL 3.0, Karate, Karate with Zeon Technology, Lamcap, Lamcap II, Lamdec, Lexar EZ, Lumax EZ, Medal II ATZ, Minecto Pro, Proclaim, Tavium Plus VaporGrip Technology, Voliam Xpress and Warrior II with Zeon Technology are Restricted Use Pesticides.

Some seed treatment offers are separately registered products applied to the seed as a combined slurry. Always read individual product labels and treater instructions before combining and applying component products. Orondis Gold may be sold as a formulated premix or as a combination of separately registered products: Orondis Gold 200 and Orondis Gold B.

Important: Always read and follow label and bag tag instructions; only those labeled as tolerant to glufosinate may be sprayed with glufosinate ammonium-based herbicides. LibertyLink®, Liberty® and the Water Droplet logo are registered trademarks of BASF. HERCULEX® and the HERCULEX Shield are trademarks of Corteva Agriscience LLC. HERCULEX Insect Protection technology by Corteva Agriscience LLC. Under federal and local laws, only dicamba-containing herbicides registered for use on dicamba-tolerant varieties may be applied. See product labels for details and tank mix partners. Golden Harvest® and NK® soybean varieties are protected under granted or pending U.S. variety patents and other intellectual property rights, regardless of the trait(s) within the seed. The Enlist E3® soybean, LibertyLink®, LibertyLink® GT27®, Roundup Ready 2 Xtend®, Roundup Ready 2 Yield® and XtendFlex® soybean traits may be protected under numerous United States patents. It is unlawful to save soybeans containing these traits for planting or transfer to others for use as a planting seed. Only dicamba formulations that employ VaporGrip® Technology are approved for use with Roundup Ready 2 Xtend® and XtendFlex® soybeans. Only 2,4-D choline formulations with Colex-D® Technology are approved for use with Enlist E3® soybeans. ENLIST E3® soybean technology is jointly developed with Corteva Agriscience LLC and M.S. Technologies, L.L.C. The ENLIST trait and ENLIST Weed Control System are technologies owned and developed by Corteva Agriscience LLC. ENLIST® and ENLIST E3® are trademarks of Corteva Agriscience LLC. GT27® is a trademark of M.S. Technologies, L.L.C. and BASF. Roundup Ready 2 Xtend® , Roundup Ready 2 Yield®, XtendFlex®, VaporGrip® and YieldGard VT Pro® are registered trademarks used under license from the Bayer Group.

Trademarks are the property of their respective owners.

Sign Up For Updates From NK Seeds

First Name is required
Last Name is required
Please enter a valid email address
Email is required
Please enter a valid zip code
Zipcode is required

Follow Us for News and Insights