Glyphosate‐Resistant Soybean Cultivar Yields Compared with Sister Lines

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.

A Meta-Analysis for the Impact of Transgenic Crop Adoption on Corn and Soybean Yield

“…In the early adoption stage of TCs, transgenic crops with IR traits usually yielded similar to near-isolines (Baute et al, 2002;Cox and Cherney, 2001;Dillehay et al, 2004;Traore et al, 2000), suggesting that the insertion of an IR gene in the early IR crops did not provide higher yield. However, some of the first transgenic crops with GR traits provide the same or even lower yield on average than conventional varieties due to the introduction of the GR gene into varieties with lower yield potential (Elmore et al, 2001;Heatherly et al, 2002 andLoecker et al, 2010;Shaw et al, 2001). However, transgenic traits were later introduced into improved potential yield varieties and generally showed that transgenic hybrids produced similar or higher yields than conventional varieties.…”

“…Brookes (2003) observed that an average 31% yield increase has been shown by the adoption of GR soybean in Romania. However, yield potential of GR soybean hybrids has been questioned in other instances (Bertram and Pedersen, 2004;Elmore et al, 2001;Oplinger et al, 1998;Thomas et al, 2007). For instance, Bertram and Pedersen (2004) found that no yield difference between transgenic and conventional soybean varieties was observed in low yield environments caused by cool weather conditions, but transgenic soybean averaged 6% less yield than conventional varieties in a high yield environment.…”

From Microphysics to Mesophysics: Obtaining Effective Properties from Microscopic Behaviors

“…While some GM technologies may lead to reduced agrochemical use, benefiting biodiversity and water quality, others could result in greater use of agrochemicals (ERS-USDA, 1999; Elmore et al 2001;Huang et al2002;Pray et al 2002). There may be an increased uptake of environmentally beneficial farm methods, such as zero or minimum tillage, which though requiring more herbicide, will lead to improved soil carbon storage and reduced run-off pollution (Renwick et al 2002).…”

Genetic Improvement: Molecular-Based Strategies

“…In 2009, GT soybeans are planted in nine countries covering 69,2 million hectares (52% of global biotech area of 134 mill ha) or 77% of total area planted with soybean (90 mil ha) (James, 2009). Results of the researches conducted by Minor (1998), Oplinger et al (1998) and Elmore et al (2001) showed that GT soybean cultivars didn't have considerably better agronomic properties than conventional cultivars concerning seed yield, seed quality and resistance to diseases. The only advantage of GT cultivars is the cheaper production process because of the lower costs of weed control.…”