Desiccant Considerations
Additional Documents
Desiccating Video file size: 18904 kb
Desiccating Video

Desiccation in Action
Sunflower Desiccation file size: 10197 kb
A view from the cab of a 4830 John Deere High Boy Sprayer desiccating sunflower on a field near Washburn, ND

Desiccant Information
Getting the sunflower crop off early with the aid of a desiccant can pay good dividends. Glyphosate is now labeled as a late season weed control and provides desiccation as well. This is a good addition to the existing labeled products paraquate (Gramoxone Max) and sodium Chlorate (Drexel Defol). All products are labeled for both oil and confection types. All labels indicate application when seed is 35% seed moisture or below or when the bracts are turning brown. This can be difficult to determine exactly, since most hybrids are now of the ‘stay green' type. Often these hybrids can have dry seed in the head but exhibit all of the color of an immature plant. Glyphosate is slow acting and research indicates that there is in most cases a margin of error if application occurs earlier than 35% seed moisture without sacrifice to yield, oil content or test weight. For more detail, go to the article in the March/April issue of The Sunflower magazine about this topic.

With today's high values, getting the crop harvested several weeks early can result in higher yields and lower drying costs. Late season crop damage is well recognized when strong winds can lodge plants or rub seed from heads. Blackbird damage can be reduced and desiccation may also slow down head diseases such as Sclerotinia. Sometimes the market will pay a premium for early delivered seed. And, it is important to harvest sunflower before corn. Early dry down can also minimize artificial drying costs. September and first half October harvest can often allow the use of air drying to lower seed moisture in storage. Air temperatures are higher and humidity tends to be lower during this time frame when compared to late October and November harvesting.
Preharvest Desiccant Information
Click here for helpful preharvest desiccant information.
 Sunflower at about 70% moisture. Too early to apply desiccant.
Sunflower at about 50% moisture. Still too early to apply desiccant.
Sunflower at about 35% moisture. Best time to apply desiccant. Back sides of heads are yellow. Bracts turning brown.
 R-8 stage at or near 35% moisture or less
R-8 stage. Florets should rub off easily with seeds fully developed.
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