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Clearfield a Good Fit for First-Time KS User

Wednesday, December 15, 2004
filed under: Weeds

Establishing a strong, uniform plant stand and obtaining good weed control are core ingredients for any successful sunflower production program. But when you've been contending with several years of drought, achieving those objectives becomes particularly difficult.

Like many High Plains dryland sunflower growers, Scott Schertz has responded to the scarcity of moisture by making significant adjustments in his production program. In Schertz's case, two key changes this past season were: (1) returning to 30-inch rows rather than solid seeding his 'flowers, and (2) opting for the Clearfield® production system in order to utilize Beyond® herbicide as the foundation of his weed control program.

Schertz, who farms with father Steve and brother Rex near the Logan County community of Winona, had been solid seeding some of his oil-type 'flowers with a Great Plains drill since the mid-1990s. Seeding rates typically were in the 20,-21,000/acre range; and, for a few years at least, plant stands and final yields were quite satisfactory. In fact, the last season before drought set in, he averaged 2,000-plus pounds across his entire sunflower acreage, with one field hitting 2,500.

The drought changed that. There've been a couple years where it wasn't worth taking the combine into the 'flowers. The 2003 story was mixed - from 1,400 pounds on some acres down to 200 on one field of 'bar pits' (terrace channels).

Still, the sunflower results have certainly outshone the corn. The same year he garnered that 2,000-pound sunflower average, Schertz's dryland corn ran 60 bushels. "We thought that was a disaster," he recounts. "But ever since then, we'd 'kill' for 60-bushel corn. We haven't pulled out the corn head since that year."

Utilizing his row-crop planter in 2004, Schertz cut his sunflower seed drop down to 14,000 "because we had no subsoil moisture." Also, he¹s concerned about stem weevil and wanted to bolster stalk size as much as possible. The lower population was aided by some timely showers, and he ended up with the best-looking stand overall that he's had in several years.

Weed control also took a definite turn for the better on the Schertz farm this past season. For that, Scott credits his utilization of the Clearfield production system.

Schertz didn¹t plant Clearfield hybrids in 2003, the first year they were available. That season, as in prior years, he relied upon a weed management program consisting of a preplant burndown, followed by pre-emerge Spartan and a later grass herbicide treatment. While he fights with several troublesome broadleaves, the grass product is key, too - particularly since sunflower follows corn in the rotation and all his corn is Roundup Ready®.

The Logan County producer applied Spartan at rates up to 4.0 ounces on some of his heavier soils without apparent sunflower crop injury. The pre-emerge product was quite effective there on broadleaves emerging after his preplant burndown treatment, he says. But Schertz's fortunes on lighter soils were not so good - even with lower rates of Spartan. "I've run 1.8 ounces on some light ground (hillsides, terrace tops) and still had bad luck [with sunflower injury]," he says.

A lack of crop injury and concurrent high level of weed control achieved during his first year applying Beyond have sold Schertz on the Clearfield approach for 2005. He says control of his major weed problems - devil's claw, puncture vine, field sandbur, bindweed and the volunteer corn - was excellent.

"We put sunflower on some fields this year that were new ground for us and were complete disasters [in terms of weed populations]. And we had beautiful 'flowers there," he states. While the Beyond was vital to weed management on those fields, his annual preplant burndown treatment - glyphosate and a light rate of low-vol 2,4-D - was key as well, Schertz adds.

Schertz was very pleased with his control of devil's claw - a difficult weed that can pose a real headache for equipment (tough mature claws wrap themselves around hoses, chains and other parts) as well as a yield robber if allowed to escape and flourish.

(In 2004 BASF received a Section 2(ee) clearance for the use of Beyond on Clearfield sunflower in Kansas for control of devil's claw. It should be applied to emerged devil's claw at or prior to the weed's four-leaf stage. Recommended rate is 4.0 ounces.

If early spring soil moisture is adequate, Scott Schertz will likely return to solid seeding his west central Kansas sunflower crop in 2005. One reason why is the John Deere no-till drill he bought prior to the 2004 season. He likes the added depth control provided by its 4" press wheels, and also touts the benefits of quicker canopy coverage from a solid-seeded crop. Still, even if soil moisture is good, he believes he¹ll back off (down to 18,-19,000) from the seeding rate of his previous solid-seeded crops.

Schertz is also considering an earlier planting date. Normally, he'll start seeding his roughly 1,400 acres of sunflower around May 10. "I've been wanting to try some April 'flowers," he says. That could prompt an insecticide treatment for stem weevil, however - an input cost he hasn¹t yet incurred.

One aspect of his production program is not likely to change much next year, though: weed control. Based upon his results in 2004, Scott Schertz plans to repeat his double-pronged approach: a preplant burndown, followed by the postemergent application of Beyond on his Clearfield sunflower hybrids. -- Don Lilleboe

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