The nation's corn crop will likely average 158.4 bu./acre in 2004, up from a record average yield of 142.2 bu./acre in 2003, according to the USDA. This year's 16.2-bu. jump is much more than the average 1.5-bu./acre increase in U.S. corn yields that typically occurs from one year to the next, says Jeff Volenec, Purdue University Extension agronomist.
"Although yields went up 16 bu./acre this year, this is not an accurate average increase across time," Volenec says. "The best indicator for future yield increases is 1.5 bu./acre, which is the long-term average increase, over decades, across a wide geographical area."
Good growing conditions are the main reason for any big yield jump from year to year, including 2004's big boost in corn yields, Volenec says. However, hybrid selection and management practices also play a part, especially over time.
"What we had this year was a very good environment for corn production across a wide area," says Volenec. "Some of the yield increase is a result of better genetics and more astute management, but the majority of the yield increase is weather related."
Weather will largely determine if the U.S. corn crop hits a third consecutive new high in 2005. "Looking at the historical data for U.S. corn yields over time (1960 to 2003), there are only four instances where yields increased in three consecutive years," Volenec points out. "That's only four times in 43 years, so it does happen, but it's more the exception than the rule."
For more information on the nation's upward trend in corn yields, click on this USDA link: www.usda.gov/nass/aggraphs/cornyld.htm.