Predicting longer-term changes in weed populations under GMHT crop management
Authors: HEARD, M S1; ROTHERY, P1; PERRY, J N2; FIRBANK, L G3
Source: Weed Research, Volume 45, Number 5, October 2005 , pp. 331-338(8)
Publisher: Blackwell Publishing
Abstract:
HeardMS, RotheryP, PerryJN & FirbankLG (2005) Predicting longer-term changes in weed populations under GMHT crop management. Weed Research, 45, 331338. Summary The UK Farm Scale Evaluations (FSE) compared the effects on biodiversity of management of genetically modified herbicide-tolerant (GMHT) crops and conventional crops over the shorter term. We simulated population changes over seven 4-year rotations (28 years) for weeds in crop rotations that included cereals and spring-sown GMHT and conventional oilseed rape and beet, using FSE data and assuming the continuation of the weed management systems practised in the FSE. The weed density dependence that was modelled integrated change caused by population dynamics and farmers responses to changes in weed density. Predicted weed seed populations decreased under conventional management and at a greater rate under GMHT. Total seed densities were lower for GMHT cropping by a factor of 0.70.8. The predicted distributions of weeds had more fields with lower weed densities under GMHT cropping. Such changes could affect animal populations on farmland, depending on the scale of uptake of GMHT crop cultivars.Keywords: arable weed; Farm Scale Evaluations; population dynamics; seedbank; genetically modified herbicide-tolerant crops
Document Type: Research article
DOI: 10.1111/j.1365-3180.2005.00465.x
Affiliations: 1: NERC Centre for Ecology and Hydrology, Huntingdon, Cambridgeshire, UK 2: Rothamsted Research, Harpenden, Hertfordshire, UK 3: NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Lancaster, UK

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