Silver Leaf Symptom in Corn

URL: http://www.kingcorn.org/news/articles.03/SilverLeaf-0529.html

R.L. (Bob) Nielsen
Agronomy Dept., Purdue Univ.
West Lafayette, IN 47907-2054
Email address: rnielsen@purdue.edu

Click on images for larger versions.

ighttime temperatures have been quite chilly around parts of Indiana for the last week or so. While there have been no reported instances of frost, there have been a number of early mornings with air temperatures in the low 40's F. If you've been out walking your cornfields recently, you may have noticed a curious leaf symptom that may remind you of freezer burn.

Rapid heat loss from terrestrial surfaces to the atmosphere (i.e., radiational cooling) can occur on clear, dry (low humidity), calm nights with temperatures in the low 40's F or cooler. Minor levels of radiational cooling can damage the outer surfaces of corn leaves that are positioned horizontally or parallel to the night sky. The subsequent symptom of such minor chilling injury is often referred to as "silver leaf" in corn.

The "silver leaf" symptom indeed appears as a silvery or dull gray leaf surface. Any portion of a leaf that was not horizontal to the sky or that was protected by another leaf or plant part will not exhibit the symptom.

The effect of this type of minor leaf damage is negligible, if any. The leaves will not die abruptly as will genuinely frosted leaf tissue. Continued expansion of the whorl will not be restricted in any way. New leaves that expand from the whorl will be normal in appearance. This symptom is more of a curiosity than a nuisance.

For more images of this oddity, see the accompanying image gallery.

Thanks to John Brien, AgriGold Hybrids, for the use of two of the images in this article.

For other Corny News Network articles, browse through the CNN Archives at http://www.kingcorn.org/news/index-cnn.html.

For other information about corn, take a look at the Corn Growers' Guidebook at http://www.kingcorn.org.

©2003, Purdue University, all rights reserved. It is the policy of the Purdue Agronomy Department that all persons shall have equal opportunity and access to its programs and facilities without regard to race, color, sex, religion, national origin, age, or disability. Purdue University is an Affirmative Action employer. This material may be available in alternative formats.

If you would like to receive Corny News Network articles and other corny information by email, contact RL (Bob) Nielsen. Other Corny News Network articles can be viewed at the CNN Archives.

Published 29 May 2003