Evaluating wind-damaged crops - Part 3

Flattened corn fields can recover from wind damage.

Posted on June 30, 2014 by Marilyn Thelen, Michigan State University Extension

Root lodged corn (V6) approximately 33 hours after the storm. Photo credit: Katie Thelen

This article is part of a flood, wind and hail series which addresses crop assessments after a weather event.

Heavy rains, strong winds, hail and even tornadoes leave their mark on fields across the Midwest every year. If your farm is in the path of one of these storms, there is not much you can do except seek shelter and assess the damage when the coast is clear.

Wind is Part 3 of this three part series on field assessment of corn and soybeans when they have been impacted by flooding, hail and wind.

Wind can take a toll on crops. Corn in the vegetative and early reproductive stages is most at risk. The two most common ways corn is damage is green snap and root lodging.

Green snap is just like it sounds – the corn plant snaps off under the pressure of the wind. Corn is most vulnerable to green snap during the rapid elongation stage (V8 – tasselling). Conditions favorable for rapid growth, good moisture and heat increase the risk of stalks breakage. According to Emerson Nafzinger, University of Illinois, the yield effects of green snap is dependent on the number of plants snapped and where the breakage takes place. If it breaks the node just below the ear, dormancy will break and allow the next ear to develop; however, this ear may produce fewer kernels due to decreased pollen. If the stalk breaks near the ground, no ear will be produced. As a general rule, there is a high potential for loss with green snap.

Root lodging looks like the corn has been “steam-rolled,” or random stalks will be flatted or tipped. Flattened plants suffer a disruption of the root system and disorientation of the leaves. If the corn is at the pollination stage when maximum photosynthetic rates are needed to assure successful pollination, the impact can be negative. Younger, more flexible corn plants will tip upward, reorienting the leaves. These plants may produce a normal ear. As plants get closer to tassel, the potential yield loss is greater. In a study by the University of Wisconsin where root lodging was simulated, corn lodged at V13-V15 saw a yield reduction of 2-6 percent whereas corn lodged after V17 experienced a 12-31 percent reduction in yield.

We are entering prime season for root lodging. Factors that can increase the risk of lodged corn are:

• Cool, wet soils leading to shallow root development.
• Root worm larva feeding – check for root feeding on lodged corn.
• Too shallow of seed placement.
• High plant population.
• Type of hybrid – look for hybrids with a good score for root lodging.

As with all types of storm damage, soon after the storm, the damaged field will look its worst – give the field several days to recover. As corn turns upward, you may notice “goose necking.” Although corn may recover and develop normally, goose necking may result in a more challenging harvest and possible harvest loss.

Wind damage in soybeans is not common, but can occur especially if the plant structure has been weakened. Herbicides with the active ingredient sulfentrazone such as Authority, Canopy XL and Cammand Xtra, can create an area of weakened tissue that may lead to plants snapping off in heavy wind or rain storms according to University of Illinois Extension.

Wind damage usually occurs later in the season when plants have some height. Before considering replant, check to see if there is enough growing season left to make replant a viable option.

This article was adapted from “Wind damage in your corn field” from Michigan State University Extension, July 9, 2012.

For more information on this topic:

• Wind damage in corn, University of Illinois
• Mid- to late-season lodging, Iowa State University
• Wind Damage to Corn and Prognosis for Recovery, The Ohio State University
• Soybean Injury from Sulfentrazone, University of Illinois Extension

See other articles in this series:

• Evaluating hail-damaged crops - Part 1
• Evaluating flood-damaged crops - Part 2

This article was published by Michigan State University Extension. For more information, visit http://www.cnchemicals.com/. To contact an expert in your area, visit http://www.cnchemicals.com/, or call 888-MSUE4MI (888-678-3464).