May 2, 2013
Drenching Rains, Low Temperatures Dampening Corn Planting Progress
It's too early to call it too late to plant corn, says a University of Missouri cereal crops specialist.
With below-average temperatures and four months of above-average precipitation, corn planting remained stagnant statewide in the third week of April, said Brent Myers, Assistant Professor of Cereal Crops Management at the University of Missouri and State Extension Specialist for Corn, Wheat, and Sorghum. The major exception was the state's Bootheel region.
Delayed planting doesn't mean yields are in danger of dropping just yet. Plenty of time for planting corn remains and Myers recommends that nervous grain producers wait before switching corn acres to other crops.
"There is still time to put corn out there," he said April 25 during a weekly meeting of state extension specialists.
Myers, whose father, David, farms in Scotland County, said there really is no comparison to last year, which was abnormally dry.
"It's night and day, but is not a useful comparison, as last year was an extreme anomaly and we can't manage for the extreme," said Myers. "At this date last year Missouri corn planting was reported to be 71 percent complete, but our recent average, including 2012 is 42. We are essentially about 25% to 30% behind in northern Missouri. But one good week and we can put this behind us, then on to beans."
Yield typically begins to drop when corn is planted after the third week of April, but only by 5 percent by May 5 and 13 percent by May 20, according to data from a four-year planting date study by MU Extension agronomist Bill Wiebold. Yield drops as much as 40 percent when corn is not planted by June 19.
"I would stick with corn through the end of May," Wiebold says. "With the high price of corn, there is financial incentive to stick with corn even with some yield loss."
The key question for producers is when does that yield loss due to planting date begin to add up?
"In general there is about a month wide window from after the first week in April to the first week in May that is 'optimal' for corn planting in northern Missouri," Myers stated. "We are still within this window, but frequent rains are pushing back field preparation and planting. This is compressing all of the spring work into whatever window is left, making producers nervous."
Myers pointed out that tillage, nitrogen applications, and burndown herbicides are still waiting in many cases.
"That being said, there is still opportunity for a good corn yield this season," he stated. "There are many other factors that impact corn yield more significantly than a minor planting delay."
Yield losses due to delayed planting will not be too large of an issue unless more widespread rain and cool temperatures occur for the next couple of weeks Myers noted.
"Unfortunately there is such a forecast for the end of this week," said Myers "This is a very widespread issue and corn planting progress will be closely followed over the next two weeks. This could very likely impact the corn market."
He highlighted the recent USDA planting progress report that showed big corn states Illinois and Iowa essentially at 0% planted.
Other factors, such as temperatures in July and August, often influence yield as much as planting date, Myers said.
The U.S. Department of Agriculture's weekly weather and crop bulletin for April 14-20 reported rains of 2.78 inches statewide, with the northeastern and north central areas drenched by as much as 4 inches of rain, causing rivers and creeks to swell.
The USDA field office in Columbia reports 13 percent of Missouri's corn crop had been planted as of April 21, most of it in the southern part of the state. This is 17 days behind the historically early 2012 crop and nine days behind the average. Nationally, 26 percent of the corn crop was planted by this time during last year's unusually warm and dry spring, compared to 4 percent this year.
Pat Guinan, extension climatologist with the MU Commercial Agriculture Program, said levels on the Mississippi River north of St. Louis have not been this high at this time of year since 1973. "For the most part, we are saturated when it comes to moisture," he said.
From March 1 to April 24, temperatures around the state averaged 12-15 degrees lower compared to the same period last year, Guinan said.
Average bare soil temperatures in the northern part of the state are still in the 40s and low 50s, well below optimal temperatures for seed germination. Seeds planted when soil is too cool germinate more slowly and are more vulnerable to disease.
Despite rain and below-average temperatures, Myers remains optimistic. He notes, however, that field prep, nitrogen and burn-down applications also are waiting to happen.