Ames, Iowa, USA
August 27, 2012

Source: Integrated Crop Management NEWS
By Aaron Gassmann and Erin Hodgson, Department of Entomology, Iowa State University

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.

Field visits in 2011 found some fields with severe root injury to Cry3Bb1 corn and to corn that produces Bt protein mCry3a, which is the Bt trait found in Agrisure (a Syngenta Product) and TRIsect (a Pioneer Product). We currently do not know the reason for the high level of rootworm injury observed for mCry3a rootworm corn, but this is an active area of research in the Gassmann Laboratory. So far in 2012, we have visited several fields with heavy rootworm feeding injury to Bt corn and patterns of injury are similar to 2011.

Full article

Website: http://crops.extension.iastate.edu

Published: August 27, 2012