Ear Size

The size of the ear of corn is dependent on three things: growing conditions, soil fertility, and variety of corn. When the corn plant is about knee high, it evaluates the growing conditions and available nutrients and decides the size and number of ears it can produce well. Keep in mind the plant is interested in reproduction, not aesthetics. The goal of the corn plant is to make the greatest number of healthy kernels it can as seed for another generation.  It doesn't know we are going to EAT it.  When conditions are good, corn will be happy to take a crack at making a nice BIG ear with lots of rows and kernels. When conditions are less than ideal during this phase, such as a cold, wet spring or a hot dry summer, the ear size is a little more modest. Early and late-planted corn experiences this often, and can usually be expected to have smaller ears as a result. The other factor in ear size is the type of variety being grown. Some varieties tend to have longer, more slender ears while others are blockier with more rows. As a general rule, the faster or earlier maturing varieties have smaller ears because they have less time to grow. Since they are making an ear of corn in only 68 days versus 85 days for a "full season" variety, this translates to 17 more days of photosynthesis or 25% more energy for the plant to use to make the ear.  So don't be surprised that the very first corn of the year isn't what you remember from last year.