The impact of gorse thrips, ryegrass competition, and simulated grazing on gorse seedling performance in a controlled environment

  • Published source details Davies J.T., Ireson J.E. & Allen G.R. (2005) The impact of gorse thrips, ryegrass competition, and simulated grazing on gorse seedling performance in a controlled environment. Biological Control, 32, 280-286.


This study is summarised as evidence for the following.

Action Category

Grow plants that compete with damaging weeds

Action Link
Natural Pest Control
  1. Grow plants that compete with damaging weeds

    A replicated, randomised, controlled trial in a greenhouse in Tasmania, Australia (Davies et al. 2005) found that ryegrass Lolium perenne competition reduced average shoot weight of invasive gorse Ulex europaeus by 96%. Ryegrass competition used together with a biological control agent (gorse thrips Sericothrips staphylinus) or with simulated grazing also increased gorse seedling mortality by 23 and 33% respectively, and by 93% when all three were combined. However, gorse seedling mortality was not affected by ryegrass, thrips or simulated grazing alone. Gorse seedlings were grown in boxes of six in a greenhouse at 20°C. Treatments were 1.5 g/m² ryegrass seeds, 10 thrips/plant and simulated grazing by cutting with scissors to 3 cm height, plus all possible combinations of these three. Each treatment was replicated five times. Seedling mortality and shoot weight after 123 days were recorded.


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