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Reduce Drying Costs

Sunday, April 1, 2001
filed under: Harvest/Storage

Steps taken early in the growing season can make a difference on how much sunflower drying you’ll need next fall.

Given much thought yet about drying your 2001 sunflower crop? If not, you should. Steps taken early in the growing season can make a difference on how much drying you’ll need for sunflower going into storage next fall. The less that drying is needed, the lower your energy bill will be.

Weed control is one factor that can influence drying.

“The better job of weed control, the less problem that’s going to be at harvest and for dry down,” says Ken Hellevang, North Dakota State University extension ag engineer. He explains that weed seeds are often higher in moisture content than the harvested sunflower kernels, and can cause storage problems. “Weed seeds tend to accumulate in pockets that can cause heating and mold growth in those areas, and the material is fine enough that it can be difficult to get air through those pockets. Ventilation air will tend to just float around the outside of the accumulated fines and weed seeds,” says Hellevang.

Anything you can do to prevent late harvesting will also reduce the need for drying.

“Harvesting earlier is going to be a big benefit from a drying standpoint, both natural air and high temperature drying. We see such a major change in temperature between October and November. The average temperature in October is 47 degrees, whereas it is 27 degrees in November. So if we can do more of our drying in October, that’s much more efficient than drying in November. It costs energy to heat that air, and so if we have to warm it an additional 20 degrees, it’s going to cost us more to do the drying,” says Hellevang.

Roger Ebel of Fessenden, ND has grown sunflower since the early 1970s, and remembers growing open-pollinated Russian varieties. He hasn’t dried sunflower for years, and credits hybrid selection as the key to that—earlier hybrids make a difference. “It boils down to variety selection. We use full floor air, but do not use an auxiliary heat source,” he says. Ebel has grown both oil and confection sunflower, and says the choice isn’t as easy for confection, since a full-season variety is generally recommended.

Planting early does indeed mean greater potential for an earlier harvest and reduced drying costs, says Duane Berglund, NDSU extension agronomist. Generally, the window between May 10 and the end of May is recommended for planting sunflower in North Dakota, depending on the growing area.

The general recommendation for sunflower planting in South Dakota is mid May to early June, according to Kathleen Grady, South Dakota State University oilseed breeder. Generally, it’s best to plant before June 15 to maximize yield and oil, she says. (For more background on early planting, see article in the February 2001 issue of The Sunflower, which can be found online at the National Sunflower Association’s web site, Click on “The Sunflower Magazine,” then “The Archives”).

Increasing plant population by about 4,000 to 5,000 plants will result in smaller sunflower heads that dry down faster, Berglund points out.

Make sure you have adequate bin space available before sunflower is harvested. And consider using a desiccant in the fall to speed drydown when the crop is mature and an early harvest would be an advantage, says Berglund, such as if birds are causing kernel losses, if weeds are likely to interfere with harvest, or if white mold threatens stands.

Natural drydown is preferred, but there are indeed instances when using a desiccant is beneficial, says Ron Meyer, Colorado State University extension agronomist, Burlington. “You never know whether you’ve made the right decision with a desiccant until the crop is off. But if you can get out and take the crop off before a snowstorm and it allows you to do that, then you’ve made the right decision,” he says. “Also, in the High Plains, if you have irrigated sunflower and want to come back in with winter wheat, then using a desiccant to get the sunflower off 10 days earlier would allow that.”

Meyer also stresses the importance of hybrid selection. Be sure to compare data on harvest moisture from both university and private company trials to evaluate which hybrids come in on the drier side at harvest, he advises.

While it’s sound management to look for ways to limit drying costs, don’t compromise the yield and quality of the crop by reducing or avoiding drying if it is indeed needed, says Berglund. He points out that some producers in North Dakota left sunflower stand in the field a bit too long last fall, hoping for natural dry-down to avoid drying costs. An early snowstorm forced some to harvest in more adverse conditions, however, and a few fields weren’t harvested at all. —Tracy Sayler

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