Common Corn Questions and Answers

Encyclopedia Article

What type of corn is grown in the United States?

There are several types of corn grown in the U.S., with the major types including field corn, sweet corn, and popcorn. All are of the species, Zea mays, and can cross pollinate. Field corn (also known as dent corn or simply, corn) occupies the majority of the corn acres in the United States, with 93.6 million acres planted in 2007 and 86.0 million acres in 2008. Of the 14.4 billion bushels produced in the United States in 2007, 42% went to animal feed, 22% to produce ethanol, 17% to export, 9% for domestic food uses, and 10% surplus. In comparison, there were only approximately 380,000 acres of sweet corn grown nationwide in 2007, with the crop used as corn on the cob or for processing as canned or frozen corn.

How many ears per plant and kernels per ear exist?

A typical corn plant produces one ear although multiple ears per plant can exist if resources (space, water, nutrients, etc.) are not limited. One silk is attached to each kernel allowing it to receive pollen. The average ear of corn has approximately 400 to 600 kernels arranged in 16 rows. Rows per ear can range from 12 to 20 with typical corn belt hybrids; genetics are the predominate factor in deciding this but growing conditions also affect it. See the following webpage for a picture of two ears with different row numbers. One bushel of corn contains about 90,000 kernels at typical harvest moistures.

What is a typical seeding rate in Iowa?

Optimum seeding rate varies based primarily on soil type and environment, with Iowa producers planting a range from 28,000 to 45,000 seeds per acre. Generally, an Iowa corn field has 30,000 plants per acre. Plant populations are increasing an average of 400 plants per acre per year.

How much does corn yield?

Corn is primarily grown as a grain crop in Iowa, although some producers harvest the plants for silage. Variation exists in yields from year to year, with Iowa corn grain yields increasing an average of 2.1 bushels per acre. The state yield for Iowa in 2008 was 171 bushels per acre.

How should I produce my sweet corn or popcorn?

Field (dent) corn is grown predominately by commercial farmers and requires production practices different, at times, from those typically used for sweet corn or popcorn which is grown in the garden or on a few acres. Two new publications (released in 2010) address specific recommendations and information for sweet corn and popcorn.

Iowa State University Agronomy Extension Corn Production