The biggest factor influencing sunflower crop success can be rotation.
Travis Iglehart’s family has been growing sunflowers for the oil, confection and conoil markets for generations, near Garrison, North Dakota. When it comes to crop rotation he’s seen the benefits first hand, with the farm’s rotation of durum, canola, wheat, soybean, corn and sunflower include substantially reducing disease and weed pressure.
He’s found planting sunflower after corn can further reduce weed competition and fertilizer inputs. “It’s a big advantage to plant sunflowers after corn. Because you heavily fertilize corn, the sunflowers seem to take less fertilizer, according to soil tests,” says Iglehart.
“After corn, the field is pretty clean. With no weeds in the sunflower field, you get a better stand and no weed competition for the crop.”
A minimum three-year rotation to reduce disease risk and weed pressure is necessary, says Alison Pokrzywinski, Nuseed sunflower technical agronomist. Rotate out of crops, such as canola, rapeseed, dry edible beans, and soybeans, that are susceptible to the same diseases as sunflowers, such as Sclerotinia, she says.
“Make sure you have some sort of grain, whether it be wheat or corn, in the rotation, so you can help keep your susceptibility down,” says Pokrzywinski.
A broad rotation also allows the use of herbicides with different modes of action, decreasing the risk of herbicide-resistant weeds in the field.
For more information on Sunflowers – Rotational Benefits review this quick agronomic presentation.