Tassel ear

Tassel ear is a physiological disorder in maize (corn) characterized by the development of an ear of grain at the location where the tassel (the male inflorescence) should normally form. This phenomenon is not a pathogen-driven disease but a significant developmental anomaly caused by environmental and hormonal stress.

The condition is strictly physiological, meaning there is no causative agent like a fungus, bacterium, or virus. It is triggered by a disruption in the plant's hormonal balance, specifically affecting the apical meristem during the transition from vegetative to reproductive growth phases. The genetic potential of the plant is essentially redirected due to extreme environmental pressure.

Symptoms are easily identifiable: the top of the corn stalk fails to produce a pollen-shedding tassel and instead develops a structures resembling an ear. These abnormal structures may be enclosed in husks, contain silk, and sometimes produce kernels, often causing the top of the plant to become heavy and susceptible to lodging.

Development and spread are tied to environmental stress factors, such as sudden temperature drops, moisture deficit, or herbicide stress occurring specifically during the early V-stages when the tassel is being initiated. When the plant experiences such stress, its regulatory systems fail to control the morphological development of the apical tissue.

The economic impact is realized through reduced grain yield and lack of pollination consistency. Since the tassel is absent or non-functional, there is less pollen available for silk fertilization across the field. To mitigate this risk, agronomists recommend selecting hybrids with proven tolerance to heat and drought stress and ensuring balanced crop nutrition to avoid mid-season developmental delays.