The Effectiveness of Asulam for Bracken Emphasis

Authors: Gavin B Stewart Andrew S Pullin Claire Tyler

Publish Date: 2007/11/01

Volume: 40, Issue: 5, Pages: 747-760

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Abstract

Bracken Pteridium aquilinum is a major problem for livestockbased extensive agriculture conservation recreation and game management globally It is an invasive species often achieving dominance to the detriment of other species Control is essential to maintain plant communities such as grassland and lowland heath or if extensive grazing by domestic stock particularly sheep is to be viable on upland margins Bracken is managed primarily by herbicide application or cutting but other techniques including rolling burning and grazing are also utilized Here we evaluate the evidence regarding the effectiveness of asulam for the control of bracken Thirteen studies provided data for metaanalyses which demonstrate that application of the herbicide asulam reduces bracken abundance Subgroup analyses indicate that the number of treatments had an important impact with multiple followup treatments more effective than one or two treatments Management practices should reflect the requirement for repeated followup There is insufficient available experimental evidence for quantitative analysis of the effectiveness of other management interventions although this results from lack of reporting in papers where cutting and comparisons of cutting and asulam application are concerned Systematic searching and metaanalytical synthesis have effectively demonstrated the limits of current knowledge based on recorded empirical evidence and increasing the call for more rigorous monitoring of bracken control techniques Lack of experimental evidence on the effectiveness of management such as rolling or grazing with hardy cattle breeds contrasts with the widespread acceptance of their use through dissemination of experienceWe would like to thank all the authors land owners and organizations who responded to our enquiries and provided information particularly Steve Clarke George Wynn Darley Matthew Denny Rob Marrs Robin Pakeman Roderick Robinson and the International Bracken Group We have found the “bracken community” to be open friendly and supportive which greatly facilitates research synthesis We also thank anonymous reviewers for comments and our colleagues Helen Bayliss Zoe Davies Tam Kabat and Phil Roberts at the Centre for Evidence Based Conservation This work was funded by English Nature and the Royal Society for the Protection of Birds

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