|Farmighetti, Robert & McGeverainder, William. The World Almanac and Book of Facts 1999. Mahwah, NY: Primedia, 1999.||"237,897 metric tons"||2.38 × 108 kg|
|Farmighetti, Robert & McGeverainder, William. The World Almanac and Book of Facts 2000. Mahwah, NY: Primedia 2000.||"247,943 metric tons"||2.48 × 108 kg|
|Farmighetti, Robert & McGeverainder, William. The World Almanac and Book of Facts 2001. Mahwah, NY: Primedia, 2001.||"239,719 metric tons"||2.30 × 108 kg|
There are different types of corn. The most commonly planted type of corn in the United States is yellow dent. Yellow dent has the highest content of vitamin A of the cereal grains. Other types of corn are; flint, pop, waxy, and sweet corn. Each type of corn has different kernel characteristics that determine how it's grown.
Good temperatures for growing corn range from 77 to 91 °F during the day, and 62 to 74 °F at night. Excessive rainfall, resulting in flooding may severely injure or kill the corn crops. This is because flooding causes a lack of oxygen needed for proper function of the roots. Corn crops can live for about four to five days under water, however they die more quickly in hot weather than in cold weather because warm temperatures speed up biochemical processes that use oxygen, and warm water has less dissolved oxygen.
Statistics show that from the years 1994 to 1998 the United States has been the leading exporter of corn. This number decreased from 1994 to 1997 and increased again in 1998. Nevertheless, the United States is still the leading nation in corn production.
Yana Nisanov -- 2001