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Desiccants speed sunflower harvest

Confection and oilseed sunflower producers may avoid harvest delays and yield loss due to inclement weather, disease, birds, lodging and seed shattering by applying a desiccant to the crop after physiological maturity occurs.

University researchers recently conducted a three-year study at six locations in North Dakota and South Dakota to investigate the effects of delayed harvest on sunflower yield and oil content. They found that lodging, seed shattering and head rot reduced yields 15% to 49%.

Key Points

• Desiccants can help dry down sunflowers. and speed up harvest.

• Harvesting earlier may reduce bird, disease and shatter losses.

• Get help determining when is the best time to apply desiccants.

Blackbirds appear to do the most damage in the first two weeks after petal drop, which usually coincides with blackbird migration in September. Desiccation makes it possible to harvest sunflowers earlier.

Other benefits to desiccation include harvesting sunflowers before corn and being able to air dry sunflowers rather than using a high-temperature dryer.

Desiccant-use guidelines

Sunflowers can be desiccated once they reach maturity at 35% seed moisture. However, most field meters don’t measure sunflower seed moisture accurately. Look for visual clues to maturity. Generally, that’s when the backside of heads are turning yellow and the bracts are turning brown. For help determining when the hybrids you are growing have reached physiological maturity, talk to your seed representative.

Desiccant products, followed by their active ingredient, include: Sharpen (saflufenacil), Gramoxone Inteon (paraquat dichloride), Drexel Defol (sodium chlorate) and Roundup (glyphosate).

Coultas is a consulting agronomist for Seeds 2000 Inc., Breckenridge, Minn., and manages applied sunflower research projects across the U.S. Contact him at

This article published in the September, 2010 edition of DAKOTA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.