Wind Injury To Corn

By David Karki

Symptoms

Last week widespread rain swept across South Dakota with some regions experiencing strong winds. Strong winds can cause considerable damage in corn. The wind affected plants usually show the following two types of symptoms:

Leaning: Leaning or ‘goose-necking’ corn is the better of the scenarios that strong winds can cause to the crop. If corn is seeded deep enough and the soil is fairly moist with well anchored roots, young leaning plants will often reorient themselves to a vertical position and produce normal ear. Sometimes leaning corn may also exhibit signs of crushed tissues on one side of the stalk in which case recovery could be slow and less uniform.

Greensnap: A sudden breakage of corn stalks by strong winds is called ‘greensnap’ or ‘brittle snap’ injury. This injury is more serious than leaning. Susceptibility to greensnap injury in corn is high when plants are in the vegetative phase of rapid stem elongation. The two most common phases prone to greensnap injury are when the growing point is emerging from the soil surface (V5 to V8) and two weeks prior to tasseling through silking (V12 to R1). Effects of greensnap injury at V5 to V8 on grain yield will be lesser than the tassel stage. This is due to increased recovery time (and resources) when the injury occurs early in the growing season.

Although uncommon, lodging due to high winds can also occur during the seed filling stages. Yield losses from the lodging during the seed filling stage can be greater than earlier stages because the plants have completed the vegetative growth and will not be able to straighten back at this stage of crop development.

Wind damage may vary greatly between field to field and farm to farm. This variability is largely due to varying wind gusts or bursts across small geographic areas. In addition, growing conditions, soil moisture content, crop management practices, hybrid genetics and herbicides may also impact the severity of wind damage in corn. One example of management factors that will increase susceptibility to wind breakage is applying nitrogen in the spring for rapid early season crop growth.
Management Considerations

Some of the considerations for managing wind injury in corn are to plant hybrids with varying maturity groups which will have different corn fields at different growth stages, choosing hybrids with better snap scores, applying growth regulators at early stage if the hybrid has low snap scores, and to plant seed at proper depth which will help avoid shallow nodal root development. Also, evaluating crop insurance options for elevated risk of wind injury is a viable consideration in managing high wind risks in corn.