uring 
  the grain filling period, developing kernels become a significant photosynthetic 
  “sink” for the products of photosynthesis and respiration. Corn 
  plants prioritize the movement of these photosynthates to the kernels, even 
  at the expense of not maintaining cellular health of stalk, leaf, and root tissues. 
  
The primary effect of severe stress on a corn plant (drought, heat, nutrient 
  deficiency, leaf diseases, insect damage, hail damage, consecutive days of cloudy 
  weather) is a reduction in photosynthetic rates. If photosynthetic capacity 
  decreases significantly during grain fill, plants often respond by remobilizing 
  stored carbohydrates from stalk and leaf tissues to supply the intense physiological 
  demand by the developing grain on the ears. In addition to physically weakening 
  the stalk of plants, remobilization of stored carbohydrates and/or the consequent 
  lower cellular maintenance of root and stalk tissues increases the susceptibility 
  of the plant to root and stalk rots.
Reports have already begun to trickle in from several areas of Indiana about 
  weak plants with varying degrees of root and stalk rot development. Growers 
  should monitor stressed fields the remainder of this month and into early September 
  for compromised stalk strength or the development of severe stalk rots and adjust 
  their harvest schedules accordingly to harvest these fields early in the season 
  before that one big storm brings the crop to its knees. 
Shaner, G. and D. Scott. 1998. Stalk Rots of Corn. Purdue Univ. Extension Publication BP-59. Available online at http://www.ces.purdue.edu/extmedia/BP/BP-59.pm65.pdf (URL verified 8/23/05).
Vincelli, Paul. 2004. Factors That Could Enhance Stalk Rots in Corn. Kentucky Pest News (Aug 2). Univ. of Kentucky. Available online at http://www.uky.edu/Agriculture/kpn/kpn_04/pn040802.htm#corrot (URL verified 8/23/05).