Emmalea Ernest, Extension Fruit & Vegetable Specialist; emmalea@udel.edu
This week we began harvesting a fresh market sweet corn trial that was planted on May 23 and noticed some ear abnormalities that were not present in the same varieties when planted on April 17. The most concerning defect that we observed was tassel interspersed with kernels on the ear, which could render the ear unmarketable. A bit of tassel growing out the end of a sweet corn ear is common, especially in some varieties. However, we observed what are called “barbell ears” in some varieties, in which two sections with kernels are joined by a section of tassel. We also observed some varieties with multiple ears developing from the first ear node. These are called multi-ears or “bouquet ears”. This abnormality could reduce the size and marketability of the primary ear.
Certain varieties produced barbell ears or ears with excessive tassel tissue in the May 23 planted trial. These defects were not present in the same varieties in the April 17 planted trial.
Some varieties had a high frequency of multiple ears produced per node.
Both barbell ears and multi-ears are associated with stress during the late vegetative growth stages. In corn, the pollen producing part of the flower (the tassel) is normally separate from the seed producing part of the flower (the ear), however the tassel and the ear begin their development with the ability to produce both pollen and seeds. Environmental stress during ear development can cause ear tissue to develop into tassel tissue instead. In other reports, cold stress has been associated with barbell ears and multi-ears, however our recent weather conditions suggest that high temperatures and/or drought might also induce these abnormalities. There are variety differences in susceptibility to these abnormalities reported by others and observed in our trial. We will use data from our trial to try to understand which of the varieties we tested are less likely to develop these disorders.
Reference
Ortez, Osler A., et al. “Abnormal ear development in corn: A review.” Agronomy Journal 114.2 (2022): 1168-1183. https://doi.org/10.1002/agj2.20986