Modern corn hybrids generally produce one ear per plant. However, if resources are plentiful, seeing more than one ear per stalk is not uncommon. When an additional ear develops on the node below the primary ear, it’s not cause for concern, as the plant will still prioritize the primary ear.

A more uncommon sight is the development of multiple ears on an individual node. In some cases, there will be a large primary ear with secondary side ears that are significantly smaller. These smaller secondary ears will likely fail to pollinate, and will have little to no impact on final yield.

However, if there is no primary ear and instead a cluster of multiple ears on a single shank, this is called bouquet ears. In this case, the ears are usually stunted and abnormal. This “bouquet” generally includes three to five ears, with as many as eight being reported (Elmore and Abendroth, 2006.) Yield impact varies greatly depending on how many plants are affected.

This abnormality is most commonly caused by a trigger (likely environmental) that results in failure of the primary ear. Ear shoot development begins around the V6 growth stage, with ear shoots initiating at all nodes approximately 1-14.

Apical dominance is a hormonal control expressed by the apical bud of a stem on all lower buds. Strong apical dominance ensures that the uppermost ear develops and suppresses the development of additional ears on lower stalk nodes.

Interestingly, the ear shank is a miniature version of the main stalk. With normal ear formation, leaves emerge from the shank nodes, which form the husk that encloses the ear. Similar to apical dominance in the plant suppressing additional ears on lower nodes, it’s also expressed by the primary ear suppressing the development of secondary ears on the same ear shank.

When regular apical dominance of the primary ear is disrupted, the hormone control is removed, and ear initiation is triggered at the shank nodes, causing the phenomenon of bouquet ears. The leading cause for this is still unknown. Many researchers point to environmental stressors like cold temperatures, extreme temperature swings, high winds, flooding, or drought stress during the primary ear formation at V6. Some hybrid differences have also been reported.