Volunteer Corn and Its Effects on Corn Rootworm Populations
Situation: The rapid adoption of stacked corn with herbicide-tolerance will foster more widespread presence of volunteer plants in both rotated soybeans and continuous corn. As seed companies stack even more herbicide tolerance traits in corn, the situation is not likely to improve. Since these volunteer plants serve as foci for larval feeding and adult egg laying, the presence of volunteer corn could affect CRW population dynamics.
Project Description: The study is designed to explore effects of volunteer, herbicide-tolerant corn, on corn rootworm populations and subsequent damage. This study conducted at UMORE Park (Rosemount) and the Southwest Research and Outreach Center (Lamberton) relies on large plots (ca. 90 ft X 90 ft) to minimize any edge effects on corn rootworm activity. The volunteer corn study features four treatments representing densities of ca. 0, 1250, 2500, and 5000 plants per acre. Data will be gathered on effects on root injury, adult emergence, activity, egg laying and yield. Analyses will address whether or not egg-laying is occurring in soybean alone, the extent of egg laying associated with the volunteer corn, and the effects of crop rotation and volunteer corn on root injury and yield. A complementary study this year will determine how presence or absence of the Bt-RW trait affects corn rootworm population dynamics.
- Determine whether or not CRW, especially NCR, lay eggs in soybean.
- Document the role of volunteer corn on the adult activity, egg laying and larval injury of CRW.
- Examine the impacts on corn injury, lodging and yield
- Provide data for modeling of resistance management strategies.
Funding and Logistical Support: This research is funded by the Minnesota Corn Research and Promotion Council and the MN Legislative Agricultural Response Fund. Seed was provided by Pioneer Hi-Breds.