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26 August 2005
World Congress on Allelopathy at Wagga Wagga
On the 21 - 26 of August, 2005, Charles Sturt University , Wagga Wagga, hosted the Fourth World Congress on Allelopathy. The Congress, which was sponsored by the E H Graham Centre, attracted speakers from over 22 countries around the world, including North America , Europe and Asia.
Allelopathy is the study of interactions amongst plants, especially the below-ground chemical competition that takes place amongst plant roots. In agricultural contexts researchers are particularly interested in cultivars that have the strongest allelopathic competition with weeds. For example, Dr Alexa Seal, an E H Graham Centre post-doctoral scientist, presented research at the Congress in which several rice varieties with the potential to help suppress rice weeds were identified. As Alexa explains in her Congress paper, research of this kind is of increasing importance because some weeds are developing resistance to chemical herbicides. Importantly, Alexa was able to demonstrate a strong correlation between her laboratory results and her observations of weed suppression by rice cultivars in the field, adding to evidence that indicates allelopathy could be a valuable component in weed control.
Other E H Graham Centre researchers who presented papers at the Congress included Min An (papers on modeling, controlling the allelopathy of vulpia residues, assessing wattle for allelopathic activity) and Tim Haig (screening for allelopathic controls of annual ryegrass). Amongst the invited papers was a contribution by Hanwen Wu, who is now an E H Graham Centre researcher. Hanwen reviewed allelopathic research on wheat cultivars and efforts to identify the genetic basis and metabolites responsible for the allelopathic potential of wheat.
Participants in the Fourth World Congress on Allelopathy, Shiming Luo and Jamal Qasem. Photo: Tim Haig.
One of the most impressive and perhaps controversial papers presented at the Congress was given by Prof. John Lovett. John provided a historic overview of allelopathy research, identifying Hans Molisch (1856-1937) as the 'Father of Allelopathy' but also giving credence to earlier Greek and Roman observations later to be identified as allelopathic phenomena, and to researchers from all over the world, including Andrei Grodzinsky (1926-1988), the 'father of allelopthay in the Soviet Union'. Two of the most important contributors to allelopathic research over the last fifty years are Elroy Rice, author of the seminal text 'Allelopathy', and George Waller, who emphasized the importance of chemistry in understanding allelopathic phenomena.
Following this comprehensive review, Prof. Lovett provided a critical assessment of current trends in allelopathic research. Controversially, the observation was made that scientists are not realizing the potential of allelopathic phenomena in the field, despite the advent of sophisticated chemical analyses and models. Cynically, it is suggested this may be the relative ease of conducting laboratory rather than field research. However, it is also suggested that this may be due to the difficulty of discerning allelopathic responses in the complexity inherent in agricultural ecosystems and the relative ease of applying herbicides to control weeds, rather than investing in allelopathic control measures. Lovett also raised the concern that the chemical compounds responsible for allelopathic phenomena are now well known and probably not patentable, but they can be as effective and cheaper than synthetic agricultural chemicals and may fit with consumer demands for healthy, natural, low-chemical input agricultural produce.
More information on the Congress, including invited and contributed papers, can be found on the Congress website.
Participants in the Fourth World Congress on Allelopathy at Charles Sturt University.
Photo courtesy of Alexa Seal