By David Karki
Several strong storms, including a derecho, have swept across South Dakota in recent months. The derecho that moved from northwest to southeast South Dakota on July 5, 2022 impacted wide areas of corn fields.
Cooler than average soil temperatures in early spring delayed corn planting in most of the state, which caused corn plants in those fields to be in various growth stages.
One question that was consistently brought up was how the lodged plants would fare in coming days. There are typically two main types of wind damage in corn, and how plants recover largely depends on wind velocity and growth stage. The wind-affected plants usually show the following two types of symptoms.
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 soil is fairly moist, with well anchored roots, young leaning plants will often reorient to vertical position and produce normal ears.
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. Harvesting speed can be slower.
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 the plant is in the vegetative phase of rapid stem elongation. Stages when the growing point is emerging from the soil surface (V5 to V8) and two weeks prior to tasseling through silking (V12 to R1) are the two most-common phases prone to greensnap injury. Effects of greensnap injury at V5 to V8 on grain yield will be lesser than the tassel stage. This is due to the longer recovery time the plant can get when injury occurs earlier in its life cycle.
Management Considerations
Levels of wind damage may vary greatly from field to field and farm to farm. This variability is largely due to varying wind gusts or bursts across small geographies. In addition, growing conditions, soil moisture content, crop management practices and hybrid genetics may also impact the severity of wind damage in corn. One example of management factors that will increase susceptibility to wind breakage is rapid early-season crop growth. Some of the considerations for managing wind injury in corn are to plant hybrids with varying maturity groups that will have different corn fields at different growth stages, choosing hybrids with better snap scores, and planting 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.
Source : sdstate.edu