Before this year, there were only four years in the past four decades where the percentage of corn planted in Indiana statewide by about May 19 was well below 50%. That’s based on USDA data collected by the National Agricultural Statistics Service going back to 1979. This year makes the fifth year.
Chris Hurt, Purdue University Extension ag economist, looked back at what happened in those other four years, seeking an indication of what could happen this year. Has the “fat lady” already sung for reasonable corn yields in Indiana for 2019?
Maybe she’s warming up, but she hasn’t sung yet, Hurt reports. In fact, based on what he discovered, there’s still hope for your corn yield in 2019. “The message from the data is, don’t give up on your 2019 corn yield possibility — at least, not yet,” Hurt says. “Two of the other four years where progress was rough like 2019 wound up with above-average-trend yields.”
The first year in the past 40 that stands out with delayed planting is 1981. Magazines carried lots of stories in August and September about harvesting late-planted corn for silage and how to handle wet corn. Fortunately, weather cooperated, and actual yield wound up 2.6% above trend for Indiana, Hurt says.
In 1996, only about 14% was planted by the end of the week corresponding with the reporting date of May 19 this year. Yields wound up lower than trend yield by 7%.
The 2002 season delivered the biggest whammy, with only 13% planted statewide by the corresponding date to May 19, Hurt says. Yields were off more than 15%.
But in 2009, with about a quarter of the corn planted by May 19, weather rebounded, and yields were 9% above trend in Indiana.
What does it all mean when you boil it down? “What really determines corn yields on a statewide basis is growing season weather, and that is still to be determined for 2019,” Hurt says. “Impacts of late planting can be offset by superior growing season conditions.”
Hurt reached that conclusion after taking a closer look at all the data for percent planted and final yields from 1979 through 2018. He reached the same conclusion as Bob Nielsen, Purdue Extension corn specialist. When it comes to proving that early planting means better corn yields, or put the other way, late planting guarantees lower corn yields, the data doesn’t back it up. Nielsen concluded that too many other variables, especially weather during the rest of the growing season, impact what happens besides planting date alone.
Would you rather have all your corn planted by May 10 or earlier and take your chances? Absolutely. It’s like a football team that gets up by two touchdowns in the first quarter right out of the gate. But is the game over? Absolutely not — there are classic examples that prove otherwise.
Here is Hurt’s bottom line: “I also looked at the data for Indiana from 1979 to 2018, and there is almost no statistical impact of planting date and final corn yields in Indiana when all years are considered,” he emphasizes. “There are some years where early-planted corn had low yields, like drought years. There are some years where very late planting has above-average yields, like in 1981 and 2009.”