Glyphosate-Resistant Soybean Cultivar Yields Compared with Sister Lines

Authors

Roger Wesley Elmore, University of Nebraska-LincolnFollow
Fred W. Roeth, Univ. of Nebraska, South Central Res. and Ext. Center, Clay Center, NEFollow
Lenis Alton Nelson, University of Nebraska-LincolnFollow
Charles A. Shapiro, University of Nebraska-LincolnFollow
Robert N. Klein, University of Nebraska-Lincoln, West Central Res. and Ext. Center, North Platte, NEFollow
Stevan Z. Knezevic, Univ. of Nebraska, Northeast Res. and Ext. Center–Haskell Ag Lab, Concord, NEFollow
Alex Martin, University of Nebraska-LincolnFollow

ORCID IDs

Charles A. Shapiro

Date of this Version

2-27-2001

Comments

Published in Agron. J. 93:408–412 (2001). Copyright 2001. Used by permission.

Abstract

Herbicide-resistant crops like glyphosate resistant (GR) soybean [Glycine max (L.) Merr.] are gaining acceptance in U.S. cropping systems. Comparisons from cultivar performance trials suggest a yield suppression may exist with GR soybean. Yield suppressions may result from either cultivar genetic differentials, the GR gene/gene insertion process, or glyphosate. Grain yield of GR is probably not affected by glyphosate. Yield suppression due to the GR gene or its insertion process (GR effect) has not been reported. We conducted a field experiment at four Nebraska locations in 2 yr to evaluate the GR effect on soybean yield. Five backcross-derived pairs of GR and non-GR soybean sister lines were compared along with three high-yield, nonherbicide-resistant cultivars and five other herbicide-resistant cultivars. Glyphosate resistant sister lines yielded 5% (200 kg ha^-1) less than the non-GR sisters (GR effect). Seed weight of the non-GR sisters was greater than that of the GR sisters (in 1999) and the non-GR sister lines were 20 mm shorter than the GR sisters. Other variables monitored were similar between the two cultivar groups. The high-yield, nonherbicide-resistant cultivars included for comparison yielded 5% more than the non-GR sisters and 10% more than the GR sisters.