The National Pilot Program Integrated Modeling System: Environmental Baseline Assumptions and Results for the APEX Model

This paper presents the underlying assumptions and results for the Agricultural Policy/Environmental eXtender (APEX) model, which was applied within an integrated modeling system for the National Polio Program (NPP) environmental baseline simulations for the Upper North Bosque River Watershed area in Texas. The system consists of an economic model linked to an environmental component comprising the field-scale APEX and watershed-scale Soil Water Assessment Tool (SWAT) models. The results are edge-of-field environmental indicators obtained from the APEX model

Managing Western Corn Rootworm with Bt Corn

During the summer of 2011, the ISU Corn Entomology Lab visited several fields in Iowa in response to complaints for rootworm injury to Bt rootworm corn, and to follow-up on fields that were visited in 2010 in response to grower complaints. To date, resistance of western corn rootworm has been found only for Bt corn producing Cry3Bb1, which was originally released as YieldGard Rootworm and is now the rootworm trait found in VTTriple and VTTriple Pro. Cry3Bb1 also is present as a pyramid with Bt toxin Cry35/35Ab1 in SmartStax

Current challenges in managing corn rootworm

Corn rootworm is a major pest of corn in the United States. In the last decade, Iowa farmers have seen many changes for managing corn rootworm. With the commercial release of transgenic Bt-rootworm corn in 2003, many farmers reduced or eliminated soil-applied insecticides to manage larvae. Western corn rootworm is adapting to transgenic technologies throughout the Corn Belt. Some continuous cornfields have larvae that can now survive at high numbers and cause severe root injury to Bt corn. We encourage farmers to use multiple strategies to protect corn.https://lib.dr.iastate.edu/extension_ag_pubs/1093/thumbnail.jp