The big story this past week was the high winds Kansas saw on Tuesday, June 9th and Wednesday, June 10th. Wind gusts reached speeds in excess of 70 mph in multiple locations across the state. With a majority of corn nearing or past the V5 stage across the state, damage to plants is a concern.
Around the V5 (fifth-leaf) stage in corn, the "growing point" moves from a protected position underground to a rapidly changing position in the above-ground portion of the plant.
I always like to describe a developing corn plant as a telescope. All of the components of the "telescope" are developed underground, and then the telescope opens from the bottom up, with the growing point at the tip (which ends up as our tassel!). Because active growth in the plant is occuring at the growing point, damage to this delicate part of the plant can cause development problems.
Above right is an image of the above-ground portion of the stem in the middle of a V6 corn plant. Notice the "telescope-like" appearance of the nodes (the rings you see around the "telescope") and the tiny, developing tassel on top. There are also obvious ear shoots developing from the upper nodes.
If the growing point is undamaged and the telescope can open unhindered, there will be no problem for a developing corn plant. However, if the stalk breaks off below the growing point, there is no chance for recovery.
I am very interested to see potential impacts of this damage in our tillering plots that experienced these high winds . Because the tillers were smaller than the main plant, thus somewhat sheltered and less of a "sail", they were undamaged, even if the plant was snapped off.
In this case, when there is no longer a main plant, tillers may provide some "insurance" and a yield back-up plan.
For more on green snap and wind damage in corn, check out this past week's KState Agronomy eUpdate article by Ignacio Ciampitti: