A corn yield that tops at 185 bu. That's above normal for many southern growers. But that kind of bin-busting yield on “wheat-corn?”

That's what Felix Smart harvested recently from corn planted after winter-wheat harvest. And wheat-corn will likely be in his rotation every time he has wheat on his Altheimer, AR, farm south of Little Rock.

“We'll do it again,” says Smart. “But since the corn is late, we know we'll also need to apply a fungicide to help prevent disease pressure.”

Wheat-beans are a norm in many winter-wheat growing areas, whether it's soft or hard wheat. But more growers see wheat harvest too late to come back with corn.

Smart, though, usually runs the wheat combine the first week of June in the south-central Arkansas location. For him, that's plenty of time to plant an intermediate-season corn right behind the combine and get a good stand in just a few days.

His rotation is normally corn, soybeans, rice and occasionally wheat. Furrow/flood irrigation helps assure there is enough water at the right time. “We've always grown corn,” says Smart, “and with the prices we've seen in corn, we have hoped to get in more acres.”

Corn usually follows soybeans the rotating year. The wheat-corn idea was part of a demonstration plot by Smart. It received notice from the target="_new">University of Arkansas (UA) in 2007. “We had a timely wheat harvest in 2007 and were finished the first week of June,” says Smart, noting that the wheat yielded about 70 bu./acre. “We felt we had time to get in a corn crop.”

A 118-120-day, Roundup Ready/Bt stacked variety was planted on 30-in. rows on June 6. A good growing season, minus any pressure from tropical storms or other major weather events, led to a timely harvest that yielded 185 bu./acre.

A new rotation was born — but with a weather-permitting disclaimer.

After corn harvest, he came back with planting wheat about Nov. 1, hoping for similar results in 2008. “We had 500 acres of wheat,” he says. “We followed that with 250 acres of corn and 250 acres of beans.

“But this time the corn only yielded 100 bu., mainly because we couldn't plant until June 21 due to wet weather,” he says.

THERE WAS ALSO a little storm called Hurricane Ike that swept up through the Midsouth. “We had a lot of corn lie down on us,” he says. “The stalks dried out before the grain.”

Little corn made a normal yield in the region. The late corn was also more susceptible to southern rust. Knowing that disease could be a problem, Smart applied 6 oz. of Quadris fungicide mixed with 4 oz. of Tilt at the silking stage. He received good disease prevention on most of his crop.

Scott Monfort, UA plant pathologist, says fungicide treatments are a must for the region's growers, whether it's wheat-corn or on any late-planted corn.

Fungicides should be applied at between 100% tassel and the brown silk stage, he says. He notes that corn planted before April 15 usually won't be as affected by southern rust. But late-planted corn will see more risk for infection and will need a fungicide application.

Part of Smart's 2007 wheat-corn includes fungicide treatment plots. The treated corn yielded 195 bu., compared to 150 bu. for check — enough evidence for Smart to keep fungicide treatments in his corn arsenal.

Smart's corn program usually involves a plant population of 34,000-40,000 seeds/acre, all Roundup Ready/Bt stacked. The wheat-corn program included a population of 33,000-36,000. Seeds are treated with Cruiser for early disease control.

Barring major weather problems, Smart sees several advantages to corn planted after wheat. With the June-planted corn, it is up in four to five days and gets the full benefit of fertilizer.

The herbicide program was also more cost effective. He applied 2 qts. of atrazine and 30 oz. of Roundup three days after planting. Smart says he will continue using the late-corn program when wheat is in his rotation, as well as wheat-beans.

His wheat-beans normally yield about 45 bu./acre, compared to 60 bu. on regular soybeans. Corn yields in the 150-bu. range would likely rival or surpass the return the beans would yield.

“I guarantee that when we plant wheat, we'll plant corn behind it again,” he says.

Monfort feels more growers will also experiment with wheat-corn in the Midsouth, especially since cotton acres are down for many. “Others are looking into it,” he says. “There likely won't be a whole lot of acres of late-planted corn, but it will increase over the years. I see more wheat-corn in the region.”

IN AREAS WHERE late freezes may damage wheat, such as the killing freezes seen in parts of the southern wheat belt in 2009, growers may want to come back with corn instead of soybeans. Such wheat must likely be terminated.

Bill Johnson, Purdue University weed scientist, notes that for wheat fields that will be terminated due to cold temperatures and planted to corn, growers should be more concerned about controlling the existing wheat than they would if they were planting soybeans.

“Corn is more sensitive to early season weed competition than soybeans, and living wheat plants are essentially weeds that can absorb nitrogen and make it unavailable for the corn plants during the same growing season,” says Johnson.

He suggests one of two herbicide programs for fields going into corn. Use of a glyphosate-based burndown program should include the use of glyphosate at 1.5 lbs./acre plus 2,4-D at 1-2 pt./acre. Johnson says 2,4-D is needed to control glyphosate-resistant marestail and help with control of emerged common lambsquarters and ragweeds.

Another program involves Gramoxone. “It may be advisable to consider the use of Gramoxone Inteon (3-4 pt./acre) plus atrazine (at least 1.5 lbs./acre) plus 2,4-D (1-2 pt./acre) if one desires to plant corn as soon as possible,” he says. “This mixture is more expensive than glyphosate plus 2,4-D, but could provide a more rapid burndown of the wheat and minimize the early season competition between the remaining wheat and newly planted corn.”

Monfort suggests that growers consult their regional corn specialist or crop consultant to determine the feasibility of a wheat-corn program and the fungicide treatments that must accompany a wheat-corn plan.