Get the Scoop on Corn Rootworm

Iowa farmers, agronomists, crop consultants and others wanting to get the scoop on corn rootworms are invited to participate in a corn rootworm field day on Thursday, Aug. 8, in Boone, Iowa, at the ISU Field Extension Education Laboratory (FEEL).  There is no attendance fee, but preregistration is required as attendance is limited to 50.

Between 8:00 – 10:00 a.m., ISU Extension specialists will perform tissue testing and do rootworm injury assessments on samples brought in by attendees.  Receive one-on-one training on using the corn rootworm injury rating scale, as well as discuss corn rootworm (CRW) management options with ISU specialists.

Even if you don’t attend next week’s field day, it’s a good time to be scouting for rootworm beetles and other insects that are actively feeding on corn silks. If silks are clipped to a length of ½” or less, pollen has a hard time landing on the silks and uneven pollination occurs.

It’s also a good time to conduct root digs.  Here are some quick tips for conducting a rootworm dig:

  1. You can’t always see feeding unless you actually wash off the roots.
  2. Rootworms can have “hot pockets” in the field, so the more locations the better.
  3. While you are digging roots, note:
    1. Insect pressure (in particular rootworm beetle feeding)
    2. Disease pressure, paying special attention to the leaves above ear leaf.
    3. Runt plants and uneven emergence.
    4. Make note of root structure after you wash off roots; notice any compacted zones and if there was any sidewall compaction during planting.
    5. Look at plant spacing.

For more information about corn rootworm management, click on the links below: