Management Practices to Maintain Stalk Quality

This season’s drought, heat, and other stress after pollination contributed to corn stalk cannibalization and overall poor stalk quality in many areas of the region. Plant stress from various sources can increase the incidence and severity of stalk rot.1

In response to stress, corn plants will mobilize sugars to fill the kernels resulting in reduced carbohydrates to maintain stalk integrity. This process is referred to as stalk cannibalization and causes disintegration of the pith cells. The weakened stalks are more susceptible to colonization by fungi and to physiological stalk lodging. While this is often called stalk rot, the fungi are primarily colonizing tissues that are predisposed due to any condition that reduces photosynthesis and the production of carbohydrates needed to fill grain and maintain stalk integrity.

Physiological stalk lodging is favored by good growing conditions early in the season, followed by stress after pollination. Stresses can include a lack of moisture, nitrogen deficiency, foliar disease, hail damage, and prolonged cool, cloudy weather. Extended periods of dry or wet weather prior to pollination followed by abrupt changes for several weeks after silking also can cause poor stalk integrity and physiological stalk lodging.

Management Options

In-season options for managing stalk and ear rots are limited and fungicides are not labeled for their control, but proactive practices can help manage stalk and ear rots in future crops.

  • Choose corn products with greater levels of resistance to stalk and ear rots and with good standability ratings.
  • Minimizing stress during the growing season can help maintain stalk quality and minimize the effect of stalk and ear rots.
  • Plant products with insect protection traits to minimize damage from stalk boring insects and to protect ears from ear feeding insects that may compromise husk coverage.
  • Apply fungicides when foliar diseases are present at high levels to help maintain healthy photosynthetic leaf area and minimize stalk cannibalization during grain fill.
  • Use recommended planting populations to decrease plant stress as higher plant populations can lead to thinner stalks. Also, maintain uniform plant-to-plant spacing.
  • Maintain balanced soil fertility, especially nitrogen and potassium, to prevent nutrient deficiencies which can lead to stalk cannibalization.
  • Crop rotation and tillage, when possible, may reduce the level of stalk rot inoculum available to infest future corn crops.
  • Reduce compaction, which encourages root depth, to lessen moisture stress under droughty conditions.

Sources: 1 Jackson-Ziems, T.A., Rees, J.M., and Harveson, R.M. 2014. Common stalk rot diseases of corn. EC1898. University of Nebraska-Lincoln. http://extensionpublications.unl.edu/ 2 Ciampitti, I., Jardine, D., Shoup, D., and Duncan, S. 2017. Considerations when harvesting drought-stressed corn for grain. Agronomy eUpdate. Issue 649. Kansas State University. https://webapp.agron.ksu.edu/agr_social/m_eu_article.throck?article_id=1517 3 Thomison, P. and Paul, P. 2012. Drought may increase stalk lodging in corn. C.O.R.N newsletter 2012-30. The Ohio State University. https://agcrops.osu.edu/newsletters/2012/30#1 4 Nielsen, R.L. 2003. Stalk health issues in stressed corn. Corny News Network. https://www.agry.purdue.edu/ext/corn/news/articles.03/stalkhealth-0813.html Web sources verified 10/08/18. 181009102200