During the growing season, SDSU Extension provides weekly production recommendations.
All Oilseed Content
While scouting canola this week, I came across a field that had plants along the edge that looked like they were suffering from drought stress, but given the recent rain I doubted that to be the case. Closer inspection of the stressed plants indicated that they were covered in false chinch bugs. Although false chinch bugs are not normally an issue in canola, very large populations do have the potential to reduce yield.
In South Dakota, sunflower flowering is getting underway. That means it is time to start scouting fields for red sunflower seed weevils.
We have received reports of false chinch bug populations in canola this week. Heavily infested canola fields will sometimes appear drought stressed, but closer inspection reveals that false chinch bugs are the culprits for the wilting plants.
When scouting sunflower, the most observed weevil is the red sunflower seed weevil. However, there are two species of seed weevils that can be present on sunflower heads in South Dakota.
Grasshoppers continue to be an issue in some areas of South Dakota. The hotspots seem to be along the Missouri River, but it is a reminder that everyone should be monitoring their crops for grasshopper feeding.
Sclerotinia diseases are a concern in sunflowers, because the fungus can infect the plant through the root, mid-stalk or the head. Wet weather and cool temperatures two-to-three weeks prior to and during flowering favor disease development.
Banded sunflower moths are active in South Dakota, which means it is time to start scouting sunflowers for their eggs. Banded sunflower moth caterpillars can reduce yields and oil content by feeding on the developing florets and tunneling into developing seeds.
Every year, there is a risk that sunflower in South Dakota will be infested by Dectes stem borer larvae. At this point in the season, adults are active, and females have likely been laying eggs in sunflower plants.
The sunflower moth and its subsequent caterpillar are sunflower pests that need to be scouted for after the inflorescences begin to open through head maturity. Sunflower heads are most-susceptible to caterpillar damage from the onset of anthesis to when the petals begin drying.