As sunflower bloom is in full swing, Alison Pokrzywinski – Nuseed’s NA Sunflower Product Manager, would like to take this opportunity to share what the Nuseed team has been seeing and hearing around the countryside about insects in sunflower growers’ fields and what to be watching for.
Insects to be scouting for in your sunflower fields during bloom time:
Red Sunflower Seed Weevil
While numbers are not at record highs by any means, it is still important to scout and be aware of thresholds. With high prices, thresholds have actually dropped a bit. Oilseeds are 3-4 weevils per head and confections are 1 weevil per head.
As ha is continuing to be cut and wheat is being harvested, grass hoppers will continue to move into “greener fields”. When grasshopper pressure is high they can cause damage to sunflowers, eating the petals, bracts and upper leaves. Maintaining upper leaf health and integrity is important. Thresholds are 8-14 grasshoppers per square yard.
Branded Sunflower Moth
NDSU Crop & Pest Report and Nuseed traps in South Dakota have shown very high numbers. These moths can be difficult to scout for during the day, best time is at dusk or after sunset. Much like the seed weevils, it’s the larvae that do the damage on the seed.
An additional comment regarding Banded Sunflower Moth and Sunflower Moth, they are not as easy to scout for as the Red Sunflower Weevil and are often dismissed. Out of sight, out of mind. In a year where many areas are drought stressed, we are already up against lower yield and lower test weight concerns. These moths can also affect both yield and test weight. So for those growers planning on selling into the bird food market, an insecticide application at the proper timing could make the difference between 28 pound test weight and unsellable 27 pound test weight sunflowers, at least for the bird foot market.
For more detailed information about these insects please see the NDSU Pest Management of Sunflower Insect Pests in the Northern Great Plains website page and the NDSU Crop & Pest Report | August 5, 2021.