Originally published in Purdue Pest Management & Crop Production Newsletter (7 June 1996)

MULE Damage is Back!

R.L. (Bob) Nielsen , Agronomy Department , Purdue University, West Lafayette, IN 47907-1150
Internet address: rnielsen@purdue.edu

Not unexpectedly, some growers are reporting problems with corn leafing out underground instead of emerging normally. The reason this is not surprising is because the 1996 growing season to date has been one that is very conducive to such a problem.

Multiple underground leaf emergence (MULE) can be caused by many factors, most of which exist in many fields this year. The emergence process plus the factors that can cause MULE were described in an earlier article. Briefly, the causal factors include:

  1. Seedbed conditions that allow deeper penetration of sunlight that stops elongation of the mesocotyl (cloddy soils, open slots in no-till, surface cracks in a crusty seedbed).
  2. Injury from certain herbicides, including acetochlor, alachlor, metolachlor, dimethenamid.
  3. Surface crusting, planter furrow compaction, dense surface soil.
  4. Cold soil temperature injury.

Where these factors are combined with hybrids with below-average 'germination strength' (due to genetics or seed quality) or injury from soil-borne insects or disease, MULE damage can be especially prevalent.

Return to the the Chat 'n Chew Cafe.

The Corn Growers Guidebook , a WWW resource for corn management systems in Indiana and the eastern CornBelt.

Purdue University Agronomy Extension WWW Home Page.

Purdue Agronomy On-Line! , Purdue's Agronomy Department WWW Home Page.

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