Severe wind storms at this time of the year can be devastating to a corn field. When corn plants are rapidly growing, there are inherent risks to standability if the wind blows hard enough and at the wrong time.
Just as the plant above the ground is growing fast prior to pollination, the plant below the ground is also growing fast. Roots will not have achieved their maximum foot print until about the milk stage of development. During a storm, when rains soften the soil and winds push on the plant, roots can break loose from the soil causing the plant to lean over. Damage sustained to roots by rootworm feeding, cultivator injury, and compaction can also pre-dispose plants to root lodging. The good news is that at this stage the corn stalk can “goose-neck” back upright in a matter of days. There can be anywhere from moderate to no damage to final yield from root lodging, depending on severity.
Brittle Snap (Greensnap)
Brittle Snap can have a greater impact on yield than root lodging. This is because stalk breakage or “snap” happens below the ear (or where the ear was going to be). Brittle snap happens where the node and internode meet, which is also where corn stalk growth takes place (see figure 1).
Figure 1 - Picture of brittle snap, also known as Greensnap
During rapid growth, the cells at the base of the internode expand and basically push the plant upward. In some ways this is similar to a grain bin being built by adding rings at the base. While cells are rapidly elongating, the cell walls are flimsy because they haven’t yet established their permanent structure that will make them strong during grain fill and harvest.
We know that some hybrids have a higher risk of snapping than others. Hoegemeyer utilizes a team of research scientists and agronomists to evaluate various standability traits of our products every year. With machines like Boreas (figure 2), research scientists bring the wind to the corn rather than having to wait for high winds to happen. We also rely on natural wind events in plots over a wide geography for evaluating standability. Through all of this research, we have found some level of predictability on each hybrid’s level of brittle snap risk. This screening process allows us to weed out the hybrids that bring an unacceptable level of risk for our customers.
Figure 2 - Picture of the Boreas machine that mimics wind patterns, letting researchers understand a corn's standability rating.
The perplexing aspect of brittle snap is that even among hybrids with average to above average tolerance to brittle snap, there is still an element of unpredictability. The unpredictability is due in large part to timing. Just like kids, different hybrids hit growth spurts at different times. Hybrid A may be more at risk on July 7, while Hybrid B may be more at risk on July 14. This helps explain why a hybrid rated “6” for brittle-snap may sometimes have a higher number of snapped plants than a hybrid rated “5”.
The next several weeks are a critical period for both standability and yield for corn. While we can never eliminate all of the risks that come with farming, hopefully our product selection and placement will help minimize some of the risks that come with summer storms.