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K-State Agronomy eUpdates

Department of Agronomy

Kansas State University

1712 Claflin Rd.

2004 Throckmorton PSC

Manhatan, KS 66506

785-532-6101

agronomy@ksu.edu

Extension Agronomy

Updated publication on abnormal corn ears now available


The following is an abbreviated version of the newly updated Kansas State Research and Extension publication, EP169 “Abnormal Corn Ears”. Learn the causes of various corn ear deformities and how to identify them in the field with this 16-page publication containing many full-color photos. The author is Ignacio Ciampitti, Associate Professor and Crop Production and Cropping Systems specialist.

The entire publication can be found online at: https://www.bookstore.ksre.ksu.edu/pubs/EP169.pdf

 

Introduction to abnormal corn ears

Abnormalities in corn ears affect corn yield and quality. In most cases, abnormalities in corn ears originate from environmental conditions such as heat, drought, nutrient deficiencies, insects, and diseases, or through the misapplication of chemicals. Often, not much can be done to correct these issues, but proper diagnostics can prevent future issues.

Over the last decade, several factors have been identified as being responsible for ear abnormalities. The answer for each specific situation is yet to be determined. This document provides guidance regarding the potential causes for these issues and how to identify the abnormalities.

Potential factors affecting ear development

Some of the factors described by previous studies are:

  • Application of herbicides (some weeks before flowering)
  • Application of fungicides
  • Environmental conditions around silking time (heat, drought, and nutrient deficiencies, among several other factors)
  • Insect damage in exposed ears
  • Disease pressure
  • Hail damage, flooding, and other miscellaneous biotic or abiotic factors.


If the problem is associated with the weather, there is not much farmers can do to fix the problem. The environment influences ear development well before the silking period (R1 stage, flowering). In corn plants, the ear shoot is initiated by V5 or V6 (five- or six-leaf stages). Final row and kernel numbers, two main critical components for corn yield, are determined when the potential number of kernels is finalized around V15 (around 2 weeks before silking, depending on the environment, hybrid, and management practices).

Final ear size is a critical component in the determination of the final number of kernels in corn plants. These factors can be influenced by environmental conditions from the V5 to V15 vegetative growth stages.

The types of corn ear abnormalities discussed in detail in the publication include:

  • Arrested ears (Figure 1)
  • Banana-shaped ears
  • Bouquet ears (Figure 1)
  • Disease problems in corn ears
  • Ear stunting (Figure 1)
  • Exposed ears
  • Kernel red streak
  • Poor kernel set
  • Tassel ears
  • Tip dieback (Figure 1)

 

Figure 1. Selected photos that illustrate some of the corn ear abnormalities discussed in the updated publication. Photo credits to K-State Research and Extension.

 

Ignacio Ciampitti, Crop Production and Cropping Systems Specialist
ciampitti@ksu.edu

https://www.bookstore.ksre.ksu.edu/pubs/EP169.pdf