Corn Rootworm Monitoring: 2014 - 2016
- Evaluate and monitor corn rootworm protection of Pioneer® brand corn products with the Herculex® RW (HXRW) trait in the central and northern Corn Belt, specifically targeting fields where HXRW has been used in 2 or more consecutive growing seasons.
232 fields in Iowa, Ill., Ind., Minn., Neb., S.D. and Wis.
- Targeted fields for sampling with a history of continuous corn and continuous use of HXRW trait (Table 1).
- All fields were planted with a Pioneer brand corn product with Optimum® AcreMax® 1, Optimum® AcreMax® Xtra, or Optimum® AcreMax® XTreme insect protection in the year that sampling took place.
- Sampled 10 roots per location (5 2-plant clusters).
- Roots were washed and corn rootworm injury rated using 0-3 Node Injury Scale (NIS).
Table 1. Locations by state and history of fields sampled for evaluation of corn rootworm protection efficacy in 2014, 2015, and 2016.
- Corn rootworm injury was low at all locations in the study; average node injury score rate 0.08 across all 3 years and 232 locations.
- Corn rootworm injury did not differ based on trait use history (Table 2).
Table 2. Average node injury score (NIS) by field history.
- Corn rootworm protection of Pioneer brand corn products with the Herculex RW trait was extremely consistent across all sampling locations in 2014-2016 and was not influenced by trait use history, although corn rootworm populations were generally low across much of the Corn Belt during these growing seasons.
Although this study has shown that the HXRW trait remains an effective tool for corn rootworm management, DuPont Pioneer and university research suggests that continuous, uninterrupted use of the same corn rootworm Bt technology can lead to decreased corn rootworm susceptibility to that technology, and may result in reduced product efficacy against these insects. DuPont Pioneer recommends avoiding more than 3 years continuous use of HXRW.
- To help maintain the efficacy of Bt corn rootworm products, it is essential to develop a multi-faceted rootworm management plan.
- Your Pioneer sales professional or local Extension professionals can assist you in developing best management practices for your operation.
- Please contact your Pioneer sales professional or consult with your local University Extension for more information regarding insect resistance management, best management practices and to understand whether there has been insect resistance documented in your area.
Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents. The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. 2014-2016 data are based on average of all comparisons made in 216 locations through Sept 1, 2016. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary. 2014-2016 data are based on average of all comparisons made in 216 locations through Sept 1, 2016. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures. Individual results may vary.