Three Decades of Sunflower Success
Saturday, January 6, 2018
filed under: Optimizing Plant Development/Yields
Sunflower fields in northwestern Kansas’ Sherman County are definitely less numerous than they were a couple decades ago; but for the Duells — Steve and Colleen — of Ruleton, it remains a crop they continue to count upon year after year.
With just a couple exceptions, the Duells have incorporated sunflower into their cropping scheme for the past 30 years. Their irrigated confection ’flowers fit into a rotation that also includes irrigated corn and pinto beans, along with dryland wheat.
They contract their confections through Frontier Ag of nearby Goodland.
Strong yields and attractive contracts are, not surprisingly, at the core of sunflower’s durability in the Duell rotation. Improved confection varieties in recent years also have contributed to its success on their farm. “They (seed companies) have come out with some really good varieties the past few years,” Steve affirms. “We’ve gone from 1,500-lb/ac seeds to where we’ve approached 3,000 lbs under irrigation.”
Improved plant stands and uniformity of seed emergence have been critical components as well, Duell adds. “Used to be, for irrigated, we’d plant 19,000 and shoot for 14,000 (emergence). Now we plant 19,000 and we’ll get 18,000. Also, we used to have a two-week time frame from the first plant emergence until the last ones came up. Now, they’re all up within six or seven days of each other, at most.” The heightened uniformity of plant development is especially important when it comes to timing insecticide treatments and for uniform plant moisture levels at harvest, he points out.
The Duells strip till their row crops with a 12-row Orthman 1tRIPr unit. Sunflower follows corn in the rotation, with the upcoming sunflower ground being strip tilled in the fall. The irrigated corn residue provides ample ground cover through the ensuing months until the sunflower crop is established. (They’ll leave the following year’s sunflower stalks standing until the next spring, however, to catch snow and help blunt wind erosion over winter.)
Fertilizer for the upcoming year’s irrigated sunflower goes down with the fall strip-till pass. “Depending upon what the soil test calls for, we generally put on around 120 lbs of N, along with 30-40 lbs of phosphate, at least 10 lbs of sulfur and a little zinc,” Steve says. “We try to always have our sunflower ground ready in the fall, let it catch moisture over winter and into the spring.” A preplant treatment of glyphosate is the only field pass prior to seeding sunflower in June.
Mike Bretz, sunflower specialist with Frontier Ag at Goodland, affirms that the Duells’ success with weed control has been a key element in their overall sunflower success through the years — including management of Palmer amaranth, which has become a real problem weed in the area, along with resistant kochia.
“We go in during April-May when the weeds are coming on,” Steve relates. “We’ll apply a strong dose of glyphosate and clean things up. Then we’ll put on a half rate of Authority Elite® in May, before planting sunflower.” The other half of the Authority Elite is applied pre-emerge. “Hopefully we’ll get some rain after that; if we don’t, we might turn on the sprinkler and apply 0.5 to 0.75 inch of water to incorporate the herbicide.”
An abnormally wet spring in 2017 (including an unheard-of 7.5 inches of rainfall during May) delayed the Duells’ normal sunflower planting date by more than two weeks, into latter June. “We tried no-tilling, but that didn’t work; the ground had gotten so hard that we couldn’t get them to germinate. So we ended up waiting for it to dry a bit, then used a vertical till disk, went in real shallow — and finally got a good stand.”
Despite the late planting date, Duell says their 2017 sunflower acreage “was as clean as we’ve ever had.” He attributes that to the vertical till disk pass and their pre-emerge herbicide. With Palmer amaranth, early control is critical, he emphasizes. Hitting whatever Palmer has emerged with the high rate of glyphosate, followed by the split application of Authority Elite, “is the program we’ve found works best for us, by far,” Duell states. One primary problem with Palmer, he adds, is that even if one achieves 90-95% control, that remaining 5-10% can spread “gobs of seed. And when we cut the crop, they’re going through the combine.”
Their irrigation program on the confections is pretty standard: about 2.0 inches at pre-bud and another 2.0 inches during seed fill. Like other irrigators in the area, Steve expects lower water allocations to go into effect soon as part of the local district’s LEMA (Local Enhanced Management Areas) long-term program to conserve groundwater resources. “And that’s fine by us,” he says. “I’m fully in favor of it.”
Hail damage on part of the 2017 Duell confection sunflower crop reduced their overall yield to around 1,900 lbs/ac, whereas in most years their irrigated confections run between 2,600-2,900 lbs. Seed size was good this past season, however, at 84% large.
Asked about any particular challenges with producing irrigated confection sunflower in the northwestern corner of Kansas, Steve Duell comes up with a very short list. Dealing with Palmer amaranth and resistant kochia ranks high — as it does for many producers in the area. So too does hail — but that’s beyond anyone’s control.
“Sunflower has been good for us. The only time we’ve had a bad year is when it has hailed.
“We’ve just had really good luck with ’flowers.”
— Don Lilleboe