Biotech Corn Rootworm Protection Improves Grain Yield and Nitrogen Use of Maize

University of Illinois scientists Jason Haegele and Frederick Below conducted a study to test their hypothesis that corn rootworm resistant (CRW) Bt hybrids exhibit improved nitrogen intake, which leads to better grain yield and nitrogen use efficiency compared with the non-Bt counterparts.

In 2008-2009, the researchers tested two CRW Bt corn hybrids and their near-isogenic non-Bt herbicide resistant (HT) corn counterparts under supplemental nitrogen of 0, 67, 134, 201 or 268 kg N ha⁻¹. Minimal corn rootworm feeding pressure was observed in the roots of the Bt hybrids, but there were more grains produced compared with HT corn counterparts. At low nitrogen, Bt hybrids showed increased grain yield and 31% greater reaction to nitrogen fertilizer. With more nitrogen, the yields of both Bt and HT were similar, but the Bt corn hybrids had higher yield with an average of 38% less nitrogen fertilizer. Better nitrogen use efficiency (NUE), nitrogen uptake efficiency (NUpE), at the nitrogen rates required to optimize grain yield were observed in Bt hybrids in 2008, but the NUE and NUpE were not significantly different from the HT corn in 2009.

The researchers concluded that CRW protection through biotechnology has additional agronomic benefits such as improvement in nitrogen uptake and nitrogen use efficiency in some environments.

Read the open-access article at Crop Science: https://www.crops.org/publications/cs/abstracts/53/2/585.