Survey results on Bt corn rootworm damage

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

University of Nebraska researchers conducted a survey of crop consultants attending the December 2011 Nebraska Independent Crop Consultants Association (NICCA) meeting in North Platte to get a better idea of their experience with rootworm-active trait Bt corn hybrids in 2011. The survey was a follow-up to reports we received during 2011 of unexpected damage by rootworm larvae on Bt hybrids expressing the Cry3Bb1 protein, (see Sept. 22, 2011 CW story). Twenty-eight consultants completed part or all of the survey, the results of which are reported below. All surveys were anonymous.

  • Responding consultants worked in 47 Nebraska counties; each worked in an average of 4.4 counties
  • Unexpected rootworm injury to rootworm Bt hybrids was observed.   Yes: 16     No: 12
  • Unexpected damage was identified by:

    Root injury rating: 13
    Lodging: 16
    Yield: 8 (always coupled with the other criteria)
  • Total corn acres consulted in 2011 (all corn, not just Bt hybrids)

    369,500 acres
  • Estimated total Bt acres with unexpected rootworm injury

    10,030 acres (2.71%), all continuous corn
  • Hybrid/event with unexpected rootworm damage

    YieldGard/Genuity (Cry3Bb1): 14
    Herculex RW or HXX (Cry34/35): 4
    Agrisure RW (mCry3A): 2
    SmartStax: 2
    Optimum AcreMax: 0

These results suggest Bt rootworm problem fields were localized in areas with continuous corn and relatively uncommon in Nebraska in 2011. Although Cry3Bb1-expressing hybrids were linked with unexpected damage more than other rootworm trait Bt hybrids, we do not have data on market share in Nebraska of the different hybrids/events. This market information would help us interpret the relative frequency of unexpected damage reported for different hybrids/events. Various factors can contribute to unexpected damage by rootworm larvae. Therefore, UNL is conducting research to assess the susceptibility of Nebraska rootworm populations to rootworm-active Bt corn traits to determine if resistance to one or more Bt traits is contributing to the unexpected damage observed in the field.

More Information

See the Sept. 22, 2011 Crop Watch article, Corn Rootworm Management Update:  Ensure Diversity When Selecting Seed for 2012, for a discussion of corn rootworm management options if you experienced unexpected rootworm damage to your Bt corn hybrids in 2011.

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left

Demco 1400 Grain Cart

Demco offers a 1400 bushel grain cart to provide unmatched efficiency and operator convenience. In addition to the large 1400 ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form