Sammendrag
Docks (Rumex spp.) are a considerable problem in grassland production worldwide. We investigated how different
cultural management techniques affected dock populations during grassland renewal: (I) renewal time,
(II) companion crop, (III) false seedbed, (IV) taproot cutting (V), plough skimmer and (VI) ploughing depth.
Three factorial split-split plot experiments were carried out in Norway in 2007–2008 (three locations),
2008–2009 (one location) and 2009 (one location). After grassland renewal, more dock plants emerged from
seeds than from roots. Summer renewal resulted in more dock seed and root plants than spring renewal. Adding
a spring barley companion crop to the grassland crop often reduced dock density and biomass. A false seedbed
resulted in 71% fewer dock seed plants following summer renewal, but tended to increase the number of dock
plants after spring renewal. In some instances, taproot cutting resulted in less dock biomass, but the effect was
weak and inconsistent, and if ploughing was shallow (16 cm) or omitted, it instead increased dock root plant
emergence. Fewer root plants emerged after deep ploughing (24 cm) compared to shallow ploughing, and a
plough skimmer tended to reduce the number further. We conclude that a competitive companion crop can assist
in controlling both dock seed and root plants, but it is more important that the renewal time is favourable to the
main crop. Taproot cutting in conjunction with ploughing is not an effective way to reduce dock root plants, but
ploughing is more effective if it is deep and a skimmer is used.
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