Be aware of the differences when drying sunflowers compared to other grains.
Drying sunflowers isn’t that much different from drying other grain types, says Dr. Kenneth Hellevang, extension engineer and professor at North Dakota State University’s Department of Agriculture and Biosystems Engineering.
What’s important to remember is all grain drying fundamentals apply, no matter what method is being used to dry the grain, he says these fundamentals are found in the NDSU Extension Service Publications written by Hellevang, Natural Air and Low Temperature Crop Drying (EB-35) and Grain Drying (AE-701).
However, there are several important differences between drying sunflowers and other grains growers should understand, he says. The biggest being the grain’s weight.
“Sunflowers weigh less per bushel, so if we’re accustomed to drying corn or wheat, or something that is much heavier, you’ll find sunflowers dry quicker because there are less pounds of water that need to be removed.”
When it comes to natural-air or low-temperature in-bin drying, Hellevang says he gets many phone calls from sunflower growers in the fall who have left harvest too late, and they have run into trouble trying to dry their crops in cooler temperatures.
“The moisture holding capacity of air is related to the air temperature. If we look at drying sunflowers in late October or November, it’s going to dry much slower, and differently, than drying wheat in September,” he says. “Farmers need to make sure if they’re doing it with a natural-air drying system that they start early enough.”
Although it may be tempting for growers to delay harvest and leave a sunflower crop in the field to dry, as temperatures fall in October and November, there is less drying ability in the air. Temperatures near freezing have no drying ability left.
“Frequently I recommend people harvest [the crop] at a little higher moisture content than they might be inclined to, and then utilize the warmer air in October to dry, rather than try to dry in November,” says Hellevang.
“With temperatures down near freezing, we can’t just add a little supplemental heat and fix it. It’s very inefficient drying, and frequently the farmer needs to hold [the crop] over winter and actually do the drying in the spring and early summer, if they harvest too late in the fall.”