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Experts optimistic yields will turn out OK in 2013

By Janet Kubat Willette

Date Modified: 07/08/2013 2:41 PM

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WASECA, Minn. — The spring of 2013 is the wettest on record at the Southern Research and Outreach Center in Waseca.

Their records date to 1915, said Tom Hoverstad, scientist at SROC. Hoverstad spoke at the June 18 Agronomy Field Tour at the center. A half inch of rain just hours before the event kept everyone indoors -- the fields were too muddy.

That storyline is familiar this spring. The frequency of rainfall has been impressive, Hoverstad said. It's rained two of every three days on average. There was one stretch of four or five days in May when a lot of crops were planted around Waseca. It's been an exercise of patience since, with bursts of activity followed by more waiting. There's been plenty of opportunity to perfect one's skills at pulling out tractors buried in mud.

Thus far, the growing season is 109 growing degree units behind normal, 2.46 inches above normal on precipitation and 3.3 degrees cooler than normal.

But all hope isn't lost, said Extension corn agronomist Jeff Coulter. He is optimistic growing conditions will improve rapidly based on the forecast. The Climate Prediction Center seasonal outlook says there are equal chances for above, below and normal precipitation and temperatures in Minnesota and most of Iowa.

The pale color of some corn seedlings is related to the saturated soil, which isn't good for root development. The University of Minnesota has a supplemental nitrogen worksheet for corn to help producers decide if they need to apply additional nitrogen. The worksheet can be found at

Denitrification hasn't been a factor thus far because soil temperatures have been so cool, said Jeff Vetsch, soil scientist at SROC. However, those who applied swine manure in October 2012 may want to apply supplemental nitrogen because conditions were favorable for loss, he said.

Coulter reviewed two past planting date trials, one done from 1988 to 2003 in Lamberton and another done in Waseca from 2009 to 2011. The studies found that corn yields have 90 percent-plus yield potential when planted as late as May 25. The yield potential drops to 89 percent by May 30, 84 percent by June 4 and 79 percent by June 9, according to the study completed in Waseca. The numbers from Lamberton aren't as optimistic. Yield potential drops to 87 percent as of May 25, 82 percent as of May 30, 76 percent as of June 4 and 69 percent as of June 9.

Growing degree units received yet this growing season will have a major influence on how the crop turns out. From May 1 to May 31, only about 250 growing degree units were accumulated, Coulter said. Yield reductions due to late planting won't be as severe as a "normal" year since accumulations were less than a normal year.

Coulter said a 100-day hybrid planted June 14 probably won't make it to black layer based on growing degree day data collected at Waseca from 1978 to 2007. But a 90-day hybrid, 85-day hybrid or 80-day hybrid would, based on the historical average. A 90-day or earlier hybrid planted June 4 will likely be OK as will a 95-day or earlier hybrid planted on May 25. A rule of thumb is that growing degree days to black layer decreases by seven for each day planting is delayed beyond May 1, Coulter said.

Purple corn has also been seen this spring. Coulter said the color is common when root growth and phosphorus uptake are restricted by cool or dry conditions. It slows the movement of sugars from the leaves to the roots and the purple pigment forms, he said.

However, short-term stress on roots generally doesn't affect yield, Coulter said.

Dean Malvick, University of Minnesota plant pathologist, said growers may see more diseases this year because of the growing conditions thus far. He's received photos of diseased plants and even one sample that a farmer was worried was Goss's Wilt. It wasn't, but it can show up at any time. Conditions that favor Goss's Wilt include a susceptible hybrid, history of Goss's Wilt in the field, corn after corn, corn residue from infected crop on the soil surface and injury to leaves by hail or windblown sand or soil.

Ideal conditions exists in many fields for rhizoctonia root rot. Phytophthora also flourishes in the water-saturated soils common to the area this spring.

Cool, wet soils when soybeans are planted are also ideal for an early season infection of sudden death syndrome, he said.

Cover crops

Extension educator Jill Sackett has worked with cover crops for five years.

Producers unable to plant row crops may be planting a cover crop this year on their prevented planting acres.

Cover crops are usually planted to control erosion, but they have many benefits, Sackett said, including increasing soil organic matter, improving soil structure and providing or scavenging nitrogen.

She encouraged producers who plant cover crops to plant a mixture of crops as they do different things and work in tandem.

"Don't worry, you have plenty of time and plenty of options," Sackett said.

However, producers may want to order their seed soon because prices are moving higher and seed availability may become an issue.

Before planting, she advises producers to talk to the Farm Service Agency and their crop insurance provider.

Producers can go to the Minnesota Cover Crop Decision Tool for help in making a cover crop selection. The tool is located at . They may also contact Sackett at or 507-238-5449.

Weed control

Producers can no longer rely on one chemistry to control all weed issues, Hoverstad said. Since the mid-1990s, when Roundup became dominant, producers have spent less time scouting. However, at SROC research has continued on a bevy of weed control products.

Products in trials this year include Harness, SureStart, Verdict, Lumax, Instigate, Outlook, Sharpen, Authority First, Boundary, Gangster, Fierce and Optill Pro.

Farmers need to scout their fields and consider which weed species they have before selecting a herbicide. Other factors to consider include: Soil types, rotational restrictions, timing of application.

"It's time to start knowing a little about your weeds again," he said.


University of Minnesota Extension educator David Bau traveled to Kansas City last week and said the crops don't look much better there. He talked to someone from Illinois who said parts of the state also have late planting.

There's a $2 difference between new crop and old crop corn prices and a $3 spread between old and new crop soybean prices.

Rental rates continue to trend upward as are land values.

Input costs for corn have been increasing at a rate of 9 percent for corn since 2003 and at a rate of 7 percent for soybeans.

"So it's going to be a challenging year," Bau said.