Originally published 1996, Updated June 2008
URL: http://www.kingcorn.org/news/timeless/PondingYoungCorn.html
Effects of Flooding or Ponding on Young Corn
R.L. (Bob) Nielsen
Agronomy Dept., Purdue Univ.
West Lafayette, IN 47907-2054
Email address: rnielsen
at purdue.edu
ecent intense
rainfall events (technically referred to as “toad stranglers” or
“goose drownders”) have caused flooding of low-lying corn fields
or ponding in poorly drained swales within fields. Other areas within fields,
while not technically flooded or ponded, may remain saturated for lengthy
periods of time. What are the prospects for recently submerged corn fields?
The sarcastic answer is that flooded crops will survive until they die. What this statement means is that no one can tell you with certainty the day after the storm whether a ponded area of a corn field will survive or whether there will be long-term yield consequences until enough time has gone by such that you can assess the actual recovery of the damaged plants. We can, however, talk about the factors that increase or decrease the risks of severe damage or death to flooded soils.
- Corn that is completely submerged is at higher risk than corn that is
partially submerged.
- Plants that are only partially submerged may continue to photosynthesize, albeit at limited rates.
- The longer an area remains ponded, the higher the risk of plant death.
- Most agronomists believe that young corn can survive up to about 4 days of outright ponding if temperatures are relatively cool (mid-60's F or cooler); fewer days if temperatures are warm (mid-70's F or warmer).
- Soil oxygen is depleted within about 48 hours of soil saturation. Without oxygen, the plants cannot perform critical life sustaining functions; e.g. nutrient and water uptake is impaired and root growth is inhibited.
- Even if surface water subsides quickly, the likelihood of dense surface
crusts forming as the soil dries increases the risk of emergence failure
for recently planted crops.
- Be prepared with a rotary hoe to break up the crust and aid emergence.
- The greater the deposition of mud on plants as the water subsides, the
greater the stress on the plants due to reduced photosynthesis.
- Ironically, such situations would benefit from another rainfall event to wash the mud deposits from the leaves.
- Corn younger than about V6 (six fully exposed leaf collars) is more susceptible
to ponding damage than is corn older than V6.
- This is partly because young plants are more easily submerged than older taller plants and partly because the corn plant's growing point remains below ground until about V6. The health of the growing point can be assessed initially by splitting stalks and visually examining the lower portion of the stem (Nielsen, 2008b). Within 3 to 5 days after water drains from the ponded area, look for the appearance of fresh leaves from the whorls of the plants.
- Extended periods of saturated soils AFTER the surface water subsides will
take their toll on the overall vigor of the crop.
- Some root death will occur and new root growth will be stunted until the soil dries to acceptable moisture contents. As a result, plants may be subject to greater injury during a subsequently dry summer due to their restricted root systems.
- Concomitant (I found a new word in the dictionary!) with the direct stress
of saturated soils on a corn crop, flooding and ponding can cause significant
losses of soil nitrogen due to denitrification and leaching of nitrate N.
- Significant loss of soil N will cause nitrogen deficiencies and possible additional yield loss.
- On the other hand, if the corn dies in the ponded areas it probably does not matter how much nitrogen you've lost.
- Lengthy periods of wet soil conditions favor the development of seedling
blight diseases, especially those caused by Pythium fungi (Sweets,
2008).
- Poorly drained areas of fields are most at risk for the development of these diseases and so will also be risky for potential replant operations.
- Certain diseases, such as common smut and crazy top, may also become greater
risks due to flooding and cool temperatures (Malvick,
2002).
- The fungus that causes crazy top depends on saturated soil conditions to infect corn seedlings.
- The common smut fungal organism is ubiquitous in soils and can infect young corn plants through tissue damaged by floodwaters. There is limited hybrid resistance to either of these two diseases and predicting damage is difficult until later in the growing season.
Related References
Elmore, Roger and Lori Abendroth. 2008. Flooded Corn and Saturated Soils. Integrated Crop Management Newsletter, Iowa State Univ Extension. [On-line]. Available at http://www.extension.iastate.edu/CropNews/2008/Issues/20080602.htm [URL accessed 6/2/08].
Farnham, Dale. 1999. Corn survival in wet conditions. Iowa State Univ. Integrated Crop Management Newsletter. [On-line] Available at http://www.ent.iastate.edu/ipm/icm/1999/5-24-1999/wetcorn.html [URL accessed 6/2/08].
Malvick, Dean. 2002. Crazy Top in Corn. The Bulletin, Univ of Illinois Extension. [On-line]. Available at http://www.ipm.uiuc.edu/bulletin/pastpest/articles/200220c.html [URL accessed 6/3/08].
Nielsen, RL (Bob). 2008a. Determining Corn Leaf Stages. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.kingcorn.org/news/timeless/VStageMethods.html [URL accessed 6/1/08].
Nielsen, RL (Bob). 2008b. Growing Points of Interest. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.kingcorn.org/news/timeless/GrowingPoints.html [URL accessed 6/1/08].
Nielsen, RL (Bob). 2008c. Tips for Staging Corn with Severe Leaf Damage. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.kingcorn.org/news/timeless/VStagingTips.html. [URL accessed 6/1/08].
Nielsen, RL (Bob). 2008d. Use Thermal Time to Predict Leaf Stage Development in Corn. Corny News Network, Purdue Univ. [On-Line]. Available at http://www.kingcorn.org/news/timeless/VStagePrediction.html [URL accessed 6/1/08].
Owen, Mike. 2008a. Replant Options in Corn Fields. Integrated Crop Management Newsletter, Iowa State Univ Extension. [On-line]. Available at http://www.extension.iastate.edu/CropNews/2008/Issues/20080602.htm [URL accessed 6/2/08].
Owen, Mike. 2008b. Replanting Corn – How Do You Get Rid of the Existing Stand? Integrated Crop Management Newsletter, Iowa State Univ Extension. [On-line]. Available at http://www.extension.iastate.edu/CropNews/2008/Issues/20080602.htm [URL accessed 6/2/08].
Sweets, Laura. 2008. Seed Decay and Seedling Blights of Corn. Integrated Pest & Crop Management Newsletter, Univ of Missouri Extension. [On-line]. Available at http://ppp.missouri.edu/newsletters/ipcm/archives/v18n9/v18n9.pdf [URL accessed 6/3/08].
Thomison, Peter. 2006. Ponding Effects on Corn. C.O.R.N. Newsletter, Ohio State Extension. [On-line]. Available at http://corn.osu.edu/index.php?setissueID=134 [URL accessed 6/2/08].
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