Landholder attitudes to Onopordum thistles and their control: a preliminary view

D.T. Briese, CSIRO Division of Entomology, Co-operative Research Centre for Weed Management Systems, GPO Box 1700, Canberra, ACT 2611, Australia.


Landholders participating in a redistribution network for biological control agents of Onopordum thistles were asked to complete a questionnaire on control methods currently being used, their cost and effectiveness. The 60 replies received to date provide an interesting insight into landholder perceptions of the impact of Onopordum thistles on their farming enterprises and of current thistle management. Overall, there is no uniform control strategy, and many landholders have devised their own management plans. While cultural methods such as rotational cropping or sowing improved pastures are important, herbicides form the key component of control measures. A variety of chemicals are used, alone or in combination, with MCPA and Dicamba being the main ones. The pattern and frequency of use of herbicides is quite variable, as is their overall effectiveness. Despite some local successes, the overall picture is that current control strategies are, at best, only preventing a worsening of infestations rather than reducing the problem.


Plant Protection Quarterly (1996) 11 (Supplement 2) 281-284.