Wrapped Tassels Put Pollination at Risk

The warm, wet weather that gets corn off to a good start can also give way to disease pressure and root stress. In 2025, these conditions in the Corn Belt combined with nutrient-rich soil also led to another threat: rapid growth syndrome (RGS).

This syndrome, typically preceded by a cool weather period, causes sudden, vigorous growth that can lead to the crop’s inner leaves growing faster than the outer whorl leaves can unfurl. The result is often a high incidence of wrapped tassels — mature tassels still wrapped in the stalk’s upper leaves, which can trap pollen inside.

In most cases, the tassel eventually emerges, with pale inner leaves greening up shortly after sun exposure. But delayed pollen shed due to wrapped tassels can disrupt silk-pollen synchrony, leaving blank spots on the cob or unpollinated kernels.

Preventing Wrapped Tassels

While the urge to unwrap the tassel may be tempting, manual field intervention is not the answer. Tearing or manipulating the whorl can snap leaves, opening the door to pathogens just as disease pressure is ramping up.

A better path forward is more informed hybrid selection. Some corn hybrids seem to be more susceptible to tassel wrapping than others, but agronomists note the tendency is not brand specific. Hybrids bred for an upright leaf structure to maximize light-capture and planting density have a propensity to wrap. Because their leaves grow up rather than out, they can readily constrict the topmost whorl, catching the tassel as it tries to push through.

Hybrids with larger flag leaves or single-spike tassels are also more likely to get stuck during emergence. In contrast, open-pollinated varieties’ high genetic variability allows canopy shape and flowering windows to stagger naturally, making a field-wide, tassel-wrap takeover highly unlikely.

Splitting the planter between two high-performing hybrids across the rows, with similar relative maturities and different-but-equal traits, is a good way to mitigate tassel wrap risk. If one variety suffers from tight tassel wrap, the other is ready with a backup cloud of three- to five-million grains of pollen per plant to get the job done.

Scouting for Wrapped Tassels

When tassel wrap is suspected, agronomists advise growers to make a preliminary scouting pass during the R1-R2 silking stage followed by a second pass three to five days later. During these inspections, growers should look for twisted, bent or “buggy-whip” upper leaves shortly before tasseling.

Growers can also track pollination progress by gently husking a sample of ears to check for unpollinated kernels and conducting a shake test to see whether silks detach, which indicates pollination has occurred.

Lessons learned include the need for diversification and data-driven decisions:

• A diverse variety of hybrids is a strong defense against mid-summer weather swings and events. Get out ahead of RGS, and don’t rely too heavily on a single genetic family across the operation.
• Documentation throughout the growing season is crucial. Review the previous year’s field notes to see which hybrids and planting windows suffered the most leaf constriction and compare/contrast with insights for the upcoming season.
• Because the warm, wet conditions that cause RGS can also trigger disease development, applying fungicide at tassel can help growers get a jumpstart on pathogens like tar spot and Southern rust and preserve yield potential.