An investigation of the control of Crassula helmsii by herbicidal chemicals (with interim guidelines on control)

  • Published source details Dawson F.H. & Henville P. (1991) An investigation of the control of Crassula helmsii by herbicidal chemicals (with interim guidelines on control). Institute of Freshwater Ecology report, to the Nature Conservancy Council (GB).


This study is summarised as evidence for the following.

Action Category

Crassula helmsii: Use hydrogen peroxide to control plants

Action Link
Control of Freshwater Invasive Species
  1. Crassula helmsii: Use hydrogen peroxide to control plants

    A controlled tank trial in 1988-1989 in southern England, UK (Dawson & Henville 1991) reported that hydrogen peroxide did not reduce the biomass of C. helmsii, although no statistical tests were carried out. Tank trials using low concentrations of hydrogen peroxide did not reduce the mass of emergent or submerged C. helmsii (data not given). Treatment with a higher concentration of hydrogen peroxide led to a 24% reduction in emergent vegetation, but a 45% increase in submerged vegetation compared to a control. C. helmsii was grown either in deep water as submerged plants, or in shallow water as emergent plants, in 300 l tanks. In low concentration trials hydrogen peroxide was applied to submerged and emergent vegetation at 20 g/m2 or 100 g/m2 in autumn 1988. High concentration trials used 250 g/m2 in spring 1989. Final biomass was measured after ten weeks.


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