Biocontrol News and Information includes review articles written by
experts in the field of biological control. The abstracts of these review articles are
available to PEST CABWeb® subscribers as html
files, readable by any browser. The complete articles (including graphics, tables etc) are
provided as PDF files. In order to view these files you will need to install the Adobe
Acrobat viewer. This can be downloaded free of charge from the Adobe Web Site at : http://www.adobe.com
BNI September 2004 Vol 25. No. 3:
M. Grossrieder and
I. P. Keary
The potential for the biological control
of Rumex obtusifolius and Rumex crispus using
insects in organic farming, with particular reference to
Rumex obtusifolius and Rumex
crispus are pernicious weeds throughout their native and
introduced ranges. Infestation of grassland by R.
obtusifolius is consistently cited by organic farmers as a
particular cause for concern, although both species prove
difficult to control even when chemical interventions are
allowed. Established plants of both species possess a large and
persistent taproot that contains a large reserve of resources.
This allows individual plants to tolerate repeated defoliation.
The history and growing importance of organic agriculture in
Switzerland is outlined. Control methods compatible with organic
agriculture are reviewed, including various weeding, mowing and
cultivation strategies. The potential for limiting Rumex
populations through sward management is discussed in relation to
competition studies. Methods for depleting the seed bank and
limiting seed production are also discussed. Classical and
neo-classical, inundative and augmentative approaches to Rumex
biological control are considered. Potential insect control
agents, both native and non-native, are evaluated on the basis
of studies carried out in Europe and elsewhere, and from the
results of an Australian classical biological control programme.
It is concluded that the augmentation of native natural enemies
is the best approach for Rumex control for organic
agriculture in Switzerland, although if the classical approach
gains more acceptance in Europe, then non-native agents should
also be considered for use in a neo-classical approach.