Keep scouting fields this August, agronomists advise

ALTOONA, Iowa — Agronomists at Pioneer advise farmers to keep scouting fields in August, even as corn and soybeans rapidly mature.

Matt Vandehaar, Pioneer field agronomist, recommends scouting for diseases, examining silk feeding, looking for corn rootworm pressure and being aware of nutrient deficiencies in fields.

“Whether or not you’ve applied fungicide, continue scouting your fields,” he said. “Ensure a clean canopy around the ear, mid-canopy and above to maintain high yield potential.

“Look for tar spot, gray leaf spot, northern corn leaf blight and southern rust. These diseases can flare up late in the season, potentially overwhelming your crop.”

For late-planted fields, ensure enough silks are left for corn pollination and that they’re not clipped within a half inch of the ear.

Additionally, look for Japanese beetle and rootworm feeding, which can significantly impact pollination and crop health.

If adult rootworms are present, consider root digs to check for feeding damage below the surface, Vandehaar said.

Hybrid traits alone may not provide enough protection against high pressure, so farmers may need to consider adding soil-applied insecticides or beetle bombing to control future populations.

Extended diapause populations should be monitored and rootworm traits rotated to prevent surprises in future crops.

It’s also the time to assess cornfields for yellowing leaves that may indicate nitrogen deficiencies. Nitrogen programs should be assessed for future seasons by considering in-season applications rather than relying heavily on fall applications.

Pioneer also provided a corn weed scouting checklist:

Pre-Burndown

• Timing: Before spring burndown applications.

• Ask: What weeds are present?

• Tip: Adjust chemistries to control weeds.

Post-Burndown

• Timing: After burndown can take effect.

• Ask: Was burndown successful?

• Tip: Adjust preemergence plans if unsuccessful.

Postplant

• Timing: Less than two weeks after planting.

• Ask: Did any weeds escape preemergence?

• Tip: Apply timely postemergence.

In Season

• Timing: At least every two weeks

• Ask: What weeds, pests and diseases are present?

• Tip: Take detailed notes to keep track.

Harvest

• Timing: When you’re in the combine.

• Ask: What weed populations are present?

• Tip: Use data to inform next year’s plans