Abstract
We compared the effects of the management of genetically modified herbicide-tolerant (GMHT) and conventional beet, maize and spring oilseed rape on 12 weed species. We sampled the seedbank before and after cropping. During the season we counted plants and measured seed rain and biomass. Ratios of densities were used to calculate emergence, survival, reproduction and seedbank change. Treatments significantly affected the biomass of six species in beet, eight in maize and five in spring oilseed rape. The effects were generally consistent, with biomass lower in GMHT beet and spring oilseed rape and higher in GMHT maize. With few exceptions, emergence was higher in GMHT crops. Subsequent survival was significantly lowered for eight species in beet and six in spring oilseed rape in the GMHT treatments. It was increased for five species in maize and one in spring oilseed rape. Significant effects on seedbank change were found for four species. However, for many species in beet and spring oilseed rape (19 out of 24 cases), seed densities were lower in the seedbank after GMHT cropping. These differences compounded over time would result in large decreases in population densities of arable weeds. In maize, populations may increase.
Full Text
The Full Text of this article is available as a PDF (247.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Buckelew L. D., Pedigo L. P., Mero H. M., Owen M. D., Tylka G. L. Effects of weed management systems on canopy insects in herbicide-resistant soybeans. J Econ Entomol. 2000 Oct;93(5):1437–1443. doi: 10.1603/0022-0493-93.5.1437. [DOI] [PubMed] [Google Scholar]
- Firbank L. G., Forcella F. Agriculture. Genetically modified crops and farmland biodiversity. Science. 2000 Sep 1;289(5484):1481–1482. doi: 10.1126/science.289.5484.1481. [DOI] [PubMed] [Google Scholar]
- Hails RS. Genetically modified plants - the debate continues. Trends Ecol Evol. 2000 Jan;15(1):14–18. doi: 10.1016/s0169-5347(99)01751-6. [DOI] [PubMed] [Google Scholar]
- Heard M. S., Hawes C., Champion G. T., Clark S. J., Firbank L. G., Haughton A. J., Parish A. M., Perry J. N., Rothery P., Scott R. J. Weeds in fields with contrasting conventional and genetically modified herbicide-tolerant crops. I. Effects on abundance and diversity. Philos Trans R Soc Lond B Biol Sci. 2003 Nov 29;358(1439):1819–1832. doi: 10.1098/rstb.2003.1402. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Watkinson A. R., Freckleton R. P., Robinson R. A., Sutherland W. J. Predictions of biodiversity response to genetically modified herbicide-tolerant crops. Science. 2000 Sep 1;289(5484):1554–1557. doi: 10.1126/science.289.5484.1554. [DOI] [PubMed] [Google Scholar]