It’s always best to get out of the pickup and check your sunflower fields for cutworms shortly after planting. Several species of cutworms can have irreversible damage in the seedling stage of sunflowers. Damage is caused by cutting off the seedling, sometimes below the cotyledon or before they even emerge out of the ground. As the plant matures, damage moves to the leaves and the plant is typically able to recover (V4-V6 stage).
Factors to Consider
- Check south facing slopes first, they like the warmth
- Check areas that border grass/pasture first, or areas of a field with weed issues from the fall
- Look for bare patch in a field or a line of missing plants
- Look for cutworms during the day below the soil surface or underneath stubble
- Take note of the size of the cutworm (larger ones close to 1 1/2 will pupate soon)
Action Plan
- Economic threshold is 25-30% stand reduction or 1 small larvae per square foot
- Many insecticides work well, spraying towards nightfall is better
