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Showing posts from July, 2012

Performance problems surface again with Bt corn rootworm traits

By Ken Ostlie and Bruce Potter, University of Minnesota Extension

Bt-RW problem field with lodged corn
Calls over the last two weeks indicate Bt-RW trait performance problems may be expanding in scope. Field observations suggest corn rootworm populations have increased markedly in corn after corn fields since 2011; recent calls indicate a major expansion of the geography of performance problems into SC and WC Minnesota. Unfortunately the drought has masked the primary tip-off to severe corn rootworm injury—lodging. With injury largely completed and corn rootworm emergence peaking, now is the time to check fields for signs or symptoms of performance problems with your Bt-RW traits. Getting a handle on Bt trait performance is critical before making seed purchases for 2013. You may need to change your corn rootworm management strategy/strategies.

Tall Off Types in Wheat.

Jochum Wiersma, Small Grains Specialist

Photo 1. Variable wheat height. A fair number of spring wheat fields appear to be quite variable in plant height this season. Obviously varying degrees of drought stress can create height differences that are, in some instances rather striking (Photo 1). Differences in height, however, are more interspersed and without clear delineations and/or transitions as is the case in photo 1, it is probably not drought stress per se but one of three things:

a variety blenda variety that is segregating for plant heighta variety that suffers from a genetics anomaly that results in a chromosome being lost across generations.