Monday, November 13, 2006 - 8:00 AM

Performance of Transgenic Corn and Soybean.

Joseph Lauer, University of Wisconsin, 1575 Linden Drive - Agronomy, Madison, WI 53706

Transgenic corn and soybean have been available to farmers for a decade. Farmers wonder whether yield progress has been made and profitability has increased during this time. The objective is to describe yield progress of normal and transgenic corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] in University of Wisconsin performance trials. In 2006, transgenic corn hybrids produced 0.35 Mg ha-1 (5.6 bu A-1) more than normal hybrids. Not all corn transgenic events increase yield. During the past 10 years, transgenic corn resistant to European corn borer [Ostrinia nubilalis (Hübner)] using Mon810/Bt11 (YieldGard®) and TC1507 (Herculex I®) events increased corn yields 0.44 to 0.65 Mg ha-1 with the greatest increases observed in 2003 when yields were 1.05 Mg ha-1 greater than normal hybrids. Transgenic corn resistant to corn rootworm (Diabrotica spp.) using the Mon863 (YieldGard Plus®) event has yielded 0.25 Mg ha-1 less than normal hybrids. No yield changes have been measured for glyphosate (Roundup Ready 1 and 2®) and glufosinate (Liberty Link®) resistant corn hybrids using the MonGA21/NK603 and T25 events over performance of normal hybrids. Likewise, no yield increases have been measured for the glyphosate event in soybean compared to normal varieties. Some yield lag/drag existed for soybean early in the decade after release to farmers. Although, transgenic crops have not been embraced by all of those involved with agriculture, it is clear that yield progress has been made over normal hybrids for the Mon810/Bt11 and TC1507 events. Farmers will continue to make yield progress by selecting hybrids based upon individual performance regardless of transgenic event.