Sunflower

All Sunflower Content

aerial view of South Dakota farm and surrounding land

Crops

During the growing season, SDSU Extension provides weekly production recommendations.

Adult red sunflower seed weevil on sunflower leaf.

Did Malathion Effectively Manage Your Red Sunflower Seed Weevils?

Now that the August 31 deadline for the application of products containing malathion for red sunflower seed weevil management has passed, it is time to determine if the product was effective. South Dakota State University entomologists have received varying reports on this topic.

Aster Yellows Phytoplasma

Aster yellows is a phytoplasmal disease carried and introduced by aster leafhopper. It is known to infect over 80 different plant families, as the aster leafhopper has extremely broad feeding habits.

Red-brown colored weevil with bent antennae originating on the elongated mouthparts.

Is it Time to Spray Red Sunflower Seed Weevils?

Red sunflower seed weevil adult activity is well underway on sunflowers in South Dakota. Even though the red sunflower seed weevil numbers are down, we are still observing populations in South Dakota that are above threshold.

Light colored moth on a yellow sunflower head.

Sunflower Moths Active in South Dakota Sunflowers

We have received reports of sunflower moths present on early planted sunflowers this week. The observed sunflower moth populations are above the recommend threshold of an average of 1 to 2 moths per five heads.

Redlegged and differential grasshopper nymphs.

Grasshoppers Are Showing up in Large Numbers in Eastern South Dakota

While scouting spring wheat in Brookings County this week, we noticed grasshopper nymph populations that were close to threshold.

Young sunflower plants emerged in a vast field.

Overlapping Residual Herbicides May Be Necessary for Effective Weed Management

Weed management in sunflowers poses unique challenges. Compared with many other crops, there is a limited number of herbicides selections, especially postemergence herbicides.

Adult red sunflower seed weevil on a sunflower leaf.

Malathion receives special local needs approval to treat red sunflower seed weevils in South Dakota from July 15 to August 31, 2025

The request was submitted and approved by the Environmental Protection Agency due to the large populations of red sunflower seed weevil present in South Dakota that are resistant to pyrethroid insecticides.

Red Sunflower Seed Weevils in South Dakota

Fact sheet on red sunflower seed weevils in South Dakota

A green combine harvesting canola in a field.

Broadleaf Considerations for West River South Dakota Cropping Systems

Selecting the right crop rotation is crucial in West River South Dakota, where water use efficiency is important. Learn some key factors to consider when selecting broadleaf crops for rotations and see what some farmers in the region are already planting.