title: Effects on weed and invertebrate abundance and diversity of herbicide management in genetically modified herbicide-tolerant winter-sown oilseed rape.
abstract: We evaluated the effects of the herbicide management associated with genetically modified herbicide-tolerant (GMHT) winter oilseed rape (WOSR) on weed and invertebrate abundance and diversity by testing the null hypotheses that there is no difference between the effects of herbicide management of GMHT WOSR and that of comparable conventional varieties. For total weeds, there were few treatment differences between GMHT and conventional cropping, but large and opposite treatment effects were observed for dicots and monocots. In the GMHT treatment, there were fewer dicots and monocots than in conventional crops. At harvest, dicot biomass and seed rain in the GMHT treatment were one-third of that in the conventional, while monocot biomass was threefold greater and monocot seed rain almost fivefold greater in the GMHT treatment than in the conventional. These differential effects persisted into the following two years of the rotation. Bees and Butterflies that forage and select for dicot weeds were less abundant in GMHT WORS management in July. Year totals for Collembola were greater under GMHT management. There were few other treatment effects on invertebrates, despite the marked effects of herbicide management on the weeds.
authors.affiliation: Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK. david.bohan@bbsrc.ac.uk
authors.forename: David A
authors.initials: DA
authors.lastname: Bohan
authors.forename: Caroline W H
authors.initials: CW
authors.lastname: Boffey
authors.forename: David R
authors.initials: DR
authors.lastname: Brooks
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Clark
authors.forename: Alan M
authors.initials: AM
authors.lastname: Dewar
authors.forename: Les G
authors.initials: LG
authors.lastname: Firbank
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Haughton
authors.forename: Cathy
authors.initials: C
authors.lastname: Hawes
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Heard
authors.forename: Mike J
authors.initials: MJ
authors.lastname: May
authors.forename: Juliet L
authors.initials: JL
authors.lastname: Osborne
authors.forename: Joe N
authors.initials: JN
authors.lastname: Perry
authors.forename: Peter
authors.initials: P
authors.lastname: Rothery
authors.forename: David B
authors.initials: DB
authors.lastname: Roy
authors.forename: Rod J
authors.initials: RJ
authors.lastname: Scott
authors.forename: Geoff R
authors.initials: GR
authors.lastname: Squire
authors.forename: Ian P
authors.initials: IP
authors.lastname: Woiwod
authors.forename: Gillian T
authors.initials: GT
authors.lastname: Champion
mesh_terms: D000383:Agriculture / Q000379:methods; D000704:Analysis of Variance; D000818:Animals; D018533:Biomass; D029688:Brassica napus / Q000235:genetics*; D004351:Drug Resistance / Q000235:genetics; D006540:Herbicides / Q000633:toxicity*; D007313:Insecta / Q000187:drug effects* / Q000254:growth & development; D063245:Plant Development; D010944:Plants / Q000187:drug effects*; D030821:Plants, Genetically Modified / Q000235:genetics*; D011157:Population Dynamics; D012639:Seeds / Q000187:drug effects; D006113:United Kingdom
chemical_list: D006540:Herbicides