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Small Sunflower, Big Results

Sunday, February 15, 2004
filed under: Hybrid Selection/Planting

Bob Wagner, Kensington, Kans., jumped into sunflower in a small way last year, with big results.

Wagner traditionally has grown winter wheat and milo (grain sorghum) on his farm in the north central part of the state, but decided to try growing some sunflower as well, and planted a short stature oil hybrid.

Short sunflower hybrids – about 38”-42”, roughly half the size of a standard plant – aren’t new, but improved genetics offer a better plant today compared to past hybrids. Roger Stockton, KSU extension crops and soils specialist, says semi-dwarf or short-stature sunflower hybrids didn’t catch on when they were first introduced about 15 to 20 years ago, because of a small head that didn’t yield as well as standard height sunflower. But the newest wave of short stature sunflower has about the same size head as regular sunflower. The only differences are that the internodes are about half as long, with slightly larger leaves. “Otherwise it’s the same as a standard sunflower plant,” says Stockton.

There’s an increased interest in short stature sunflower hybrids, particularly in the High Plains. Indications are that it may use moisture more efficiently, and establish a quicker plant canopy. As well, the smaller stalks appear to be less susceptible to lodging with better stem weevil tolerance, all the while demonstrating the same yield and oil potential as standard size hybrids.

Wagner observed the advantages of shorter sunflower first-hand. While other standard-size sunflower fields in the area had problems with lodging from a combination of “wind and (stem) weevils,” his shorter-stalked plants stayed put.

He planted some of his sunflower at the end of May. Rain delayed the rest of his planting until around June 15. The early planted sunflower (24,000 plant pop.) yielded 2,700 lbs/acre with 46.3% oil – particularly remarkable since it was dryland production with no irrigation. The later-planted crop (22,000 plant pop.) was nearly as impressive, especially since it received little precipitation after it was planted. Also dryland, the crop yielded slightly over 2,000 lbs/acre, with 44% oil.

Wagner planted his sunflower into no-till wheat stubble, with a fertility plan that actually extends over several years. In the fall of 2001, he applied 140 lbs/acre of 11-52-0 (monoammonium phosphate) before planting the winter wheat. “We always put it in before wheat, and we feel it’s best utilized when we work it into the ground.”

Overapplying (the wheat crop will use about 50 to 70 lbs of actual phosphate) results in carryover phosphate for the subsequent crop planted into the wheat stubble.

After the winter wheat crop was harvested in 2002, he applied 100 lbs of actual N in the form of ammonium nitrate that fall. Then at planting in the spring of 2003, he applied 5 gallons/acre of 28% N in the sunflower rows. “There’s already plenty of N in the ground already, but the starter gets the seedlings sprouted faster and off to a better start. You could see the better vigor, those sunflowers popped right out of the ground.”

For weed control, Wagner applied glyphosate right after planting as a burndown, as well as Spartan and Prowl early in the season. He sprayed the crop once for insect control. Both weeds and insects were not a problem, he says.

With such a good crop last year, Wagner plans to grow sunflower again this year. He’ll shoot for a planting date around June 10-15, as he believes that will enable the best yield potential and may also offer good timing to avoid insect activity, such as the sunflower moth.

Short Order Rescue Crop

Ruben Richardson of Yuma, Colo., planted short stature sunflower on short order last year, as a rescue crop after his pinto beans got hailed out. He planted the sunflower around July 12, between the rows of the failed beans. He went with the short-stature oil type, thinking that it may help the crop pull through such a late planting date.

He didn’t apply any fertilizer, and for weeds, he only applied pre-plant Treflan, although he also applied Eptam on the same ground before planting the hailed-out pinto bean crop. He didn’t put down any insecticide; with the extremely late planting date, he didn’t have to. About the only other inputs he had into the crop was six to seven inches of irrigation water to push the crop along, and a whole lot of worry later in the growing season when autumn weather began to set in.

“I was freaking out every time the temperature got close to freezing,” he says. “We had our first light frost in early September. There was some volunteer corn where the stalks turned brown, but the sunflower stayed green. It seems a bit more tolerant to light frost, you really need the hard freeze below 24 degrees to kill it.”

The hard killing freeze came mid October, and then it took awhile for the crop to dry down. When he finally harvested it in December, his yield monitors estimated the crop came in at 1,400-1,600 lbs/acre. “We didn’t use a weigh wagon for a better yield estimate, and we didn’t get the oil, we just wanted to get the crop off and in the bin.”

Richardson admits that he was fortunate he didn’t have snow to contend with in his short stature sunflower crop. Though the crop turned out, he realized it was a gamble. “I don’t know if I’d ever do it again,” he says. The shorter stalks helped keep the plants from breaking later in the fall; he’s sure he would have had some lodging had he planted a conventional-height hybrid. He notes that head size was the same as a conventional hybrid. “Heads as big as dinner plates,” he says.

Better genetics, More hybrids on the way

Stockton has evaluated short-stature hybrids in yield trials the past few years, using material from Triumph Seed. In 2002, dryland plots yielded a respectable 1,700 lbs, despite dry conditions. With 7.7” of supplemental water, the short stature sunflower produced over 2,500 lbs/ac with no insect control. In both treatments, a standard height hybrid had a harvestable yield of 1,000 lbs/ac less, due in part, to increased lodging resulting from stem weevil and stem borer activity, Stockton says.

Evaluation results in 2003 were mixed and inconclusive. Plant size in the field plots was sporadic, ranging from four to over five feet. Head size was also sporadic. The reason may be that the short stature hybrid tested last year (567) was a first-year convert to NuSun, and the genetics may not have been completely stabilized. Weather problems stymied yield data from one plot location, but in another plot which looked at sunflower in a double-crop scenario, the short-stature hybrid was the top yielding sunflower.

Ben Benton, sales agronomist with Triumph Seed, Ralls, Texas, says that while sporadic plant height of 567 may have been observed by some last year, he points out that the agronomics were stable in other cases, and that the hybrid performed well for a number of growers, including Wagner and Richardson.

The company improved the genetics, and is marketing the NuSun hybrid as 667 in 2004. Along with uniform plant height, Benton notes that the short-stature hybrid has been visually observed to hold up better under hail damage compared to conventional-height sunflower. He says there is heightened interest in the downsized hybrid, and adds that a good share of seed ordered by growers is being treated with Cruiser™ insecticide.

One reason for grower interest in a shorter sunflower hybrid is for improved, cost-effective insect control. “A number of growers are interested in the potential of spraying for insects such as the head moth using their ground rigs,” he says, referring to high clearance sprayers like Row Gator. “This saves the air application cost, and allows a grower to put on more spray volume for better coverage and control.”

Benton says Triumph will release another short-stature NuSun hybrid as early as next year, followed by a Clearfield™ short-stature hybrid within a few years. A confection short-stature hybrid is also in the works. Other seed companies are developing short stature hybrids as well. – Tracy Sayler

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