Tassel Wrapping in Corn: A New Concern for Midwestern Corn Production?

News & Media

Tassel wrapping, an unusual phenomenon reported across Midwestern corn fields this summer, occurs when leaves trap the developing tassel and delay pollen shed, disrupting pollination timing and potentially reducing yields.

September 2, 2025
By Communications Office

By Dan Quinn, Ph.D., Assistant Professor of Agronomy & Extension Corn Specialist, Purdue University

This summer, an unusual phenomenon called tassel wrapping has been drawing attention across corn fields in Indiana and other Midwestern states. Tassel wrapping occurs when the uppermost leaves of the corn plant, including the flag leaf, remain tightly wrapped around the developing tassel. Instead of emerging on time, tassels are delayed, thus throwing off the critical synchrony between pollen shed and silk receptivity.

What We’re Seeing

Reports of tassel wrapping have come in from Indiana, Iowa, Illinois, Kansas, and beyond. While “twisted whorls” in young corn (rapid growth syndrome) are common and usually harmless, tassel wrapping is different because it occurs later in the plant’s growth cycle or right at pollination. Fields showing tassel wrapping often coincide with periods of rapid growth triggered by large swings in temperature, high humidity, and ample moisture.

Hybrid differences are also clear. In side-by-side comparisons, one hybrid may show severe wrapping while another nearby hybrid does not. Tassel size and morphology appear to play a role, as larger central tassel branches seem more prone to being trapped. Planting date has mattered as well, with many reports coming from corn planted in late April through mid-May.

Yield Implications

The big question: does tassel wrapping hurt yield?
The answer is: sometimes. In some fields, tassel wrapping has shown little effect on kernel set. In others, we’ve seen up to 25% of ovules unfertilized. The key issue is disrupted pollination synchrony: silks may emerge on time, but pollen is delayed, leading to poor fertilization at the base of the ear. In contrast to drought-related pollination issues, where tip kernels are lost due to late silks, tassel wrapping often affects the first silks to emerge, or those corresponding to kernels at the base of the ear.

Long, unpollinated silks are another clue as these can grow for up to 10 days if pollen is not available, crowding each other and further reducing pollination efficiency. Modern hybrids, bred to silk earlier as a stress tolerance strategy, may actually heighten the problem when tassel emergence lags.

What Farmers Should Do

Scout fields carefully—especially those planted in late April or May.
Check ears for pollination success—look for missing kernels or silks that fail to detach.
Document hybrids and conditions—this may help pinpoint patterns.
Share observations—with Extension or agronomy contacts. More data helps us understand this issue.

Looking Ahead

Tassel wrapping is still a poorly understood phenomenon. Current evidence suggests it’s linked to a combination of environmental triggers, hybrid genetics, and plant growth timing. While not every field with tassel wrapping will experience yield loss, the potential risk underscores the importance of scouting and reporting.

Corn pollination is a delicate dance between silk emergence and pollen shed, and tassel wrapping can throw that timing out of step. As we continue to gather data, your observations will be key to unraveling this puzzle and shaping recommendations for the future.