Degree Type

Creative Component

Semester of Graduation

Fall 2018



First Major Professor

Dr. Susana Goggi


Master of Agriculture (MAg)




“Ear flex” in corn (Zea mays L.) is defined as the variability of ear size which results from environmental conditions throughout the growing season (Anderson, 2000). Ear flex is determined by three components; ear length (number of ovaries per row), ear girth (number of rows around the ear) and kernel size (volume/kernel). Of these components, kernel size is often overlooked. Kernel size takes into account the depth, width, length, and weight of the individual kernels (Penn State Extension, 2014). The number of kernel rows in ears of hybrid corn typically range from 10 to 24. The final kernel row number is determined by branching patterns at the rachis apex around V6 growth stage of the plant. The number of ovaries per row of the ear is complete about one to two weeks before silk emergence occurs and the final ear length (cm) is determined after anthesis. (Purdue Agronomy Department, 2002). The environmental conditions during these developmental stages impact potential kernel number. Some of the factors that limit kernel set include; the lack of moisture, too much moisture, lack of nutrients, insufficient light reception, various diseases, and/or pest issues to list a few. Ideal growing conditions enable the development of more kernel rows and more ovaries per row or longer ear length. Both of these factors are determined primarily by genetics. The number of ovary rows is fairly stable across environments. Ovaries per row, however, can be more variable

Copyright Owner

Doug Becher

File Format


Included in

Agriculture Commons