Giant Hogweed Biocontrol Workshop 2003

An international workshop on the taxonomy, biology, and potential biocontrol of giant hogweed (Heracleum mantegazzianum) was held in Jelgava, Latvia, on 5-6 March 2003. It was attended by more than 50 researchers and practitioners from 13 European countries, of which half were participants in the European Union funded research project 'Giant Alien' [see BNI 22(3), 54N-56N (September 2001), Europe acts on invasive alien weeds).

The first session of the workshop (Wednesday afternoon) addressed general aspects of invasive species and biological control, as well as the current knowledge of the species' taxonomy and ecology. It quickly became evident that more than one invasive plant taxon is around in the European countries. To the west a species known as H. mantegazzianum prevails, whereas in the former Eastern-block countries a species known as H. sosnowskyi is dominating. These species seem to very similar in overall growth-form (monocarpic perennial) and habit, but can be distinguished by the shape of the leaves. They may be regarded as subspecies of the same species. It remains to be investigated how similar they are biologically. A third species, probably H. persicum, is found in northern Scandinavia, and differs somewhat in habit (shorter) and growth form (polycarpic perennial).

In the second session (Thursday morning) preliminary results of the Giant Alien project were presented. The population biology (including flowering, dormancy, and individual longevity) has been studied by a team from the Academy of Sciences of the Czech Republic. Among the noteworthy results were that less than 4% of the seeds shed in one growing season remained viable in the soil until the next season. Studies of annual growth rings in the roots of giant hogweed had revealed ages up to 8 years, considerably more than previously believed. Preliminary results of studies on potential insect and fungal antagonists were presented by researchers from the University of Berne and CABI Bioscience UK Centre, respectively.

The third session (Thursday afternoon) addressed the invasion in Europe of giant hogweed and methods to control it. Prior to the workshop, scientist and practitioners in 17 countries had compiled reports on the current status of the species and its control. See 'Status reports' at:

www.flec.kvl.dk/giant-alien/

Experiments conducted by the Danish Forest and Landscape Research Institute suggested that sheep grazing is the cheapest non-chemical control method known so far.

The Giant Alien project continues for another 2 years. Hopefully, insect and /or fungal antagonists will be found in Europe or in the Caucasus, the native range of the species, potentially controlling this pernicious invasive weed.

By: Hans Henrik Bruun, Danish Forest and Landscape Research Institute, Hørsholm Kongevej 11, DK-2970 Hørsholm,
Denmark
Email: hpr@fsl.dk

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International Congress of Plant Pathology

The 8th International Congress of Plant Pathology (ICPP2003) was held in Christchurch, New Zealand on 2-7 February 2003, and was attended by over 1200 delegates. The Congress had an overarching theme of 'Solving problems in the real world', with keynote themes of: Plant pathology in the Asia/Pacific region; Towards integrated control of soilborne disease; Host/pathogen interactions and molecular plant pathology; Towards integrated control of airborne disease; and Knowledge transfer for plant pathology. Global Food Security was addressed in a Public Forum evening session, while a wide range of specialist plant pathology topics formed the foci of numerous satellite workshops and evening sessions. Following plenary lectures each morning, delegates were given the choice of four concurrent themed sessions; in total over 150 presentations were made by invited speakers. Two afternoons were set aside during the week for delegates to study and later to discuss the offered posters (over 1200 submissions). A number of cross-cutting topics became evident as the conference progressed.

Quarantine and Biosecurity

Many of the lectures focussed on the importance of quarantine and biosecurity, and the problems associated not only with potential and actual crop losses, but also with financial and political constraints of phytosanitary issues and trade barriers. Prof Mike Wingfield (University of Pretoria, South Africa) also made this his topic for the McAlpine Memorial Address on the increasing threat of disease to exotic plantation forests in the Southern Hemisphere. He chose Cryphonectria canker of Eucalyptus to illustrate differences in taxonomy and virulence between apparently similar isolates on different continents. More research into taxonomy and reclassification of exotic forestry pathogens was called for. Also, there seems to be increasing awareness of the importance of accurate new geographic records to keep track of the invasive potential of new pathogens.

Food Security

The importance of protecting the world's food supply, especially in developing countries where the population is still increasing and there is poor disease awareness was a theme running through the whole congress. Linking in with quarantine and biosecurity, it also highlighted the continuing need for integrated research and development (chemicals, natural products, biocontrol agents, induced resistance, the introduction of resistance genes from plants and fungi into crops, etc.). Tied in with this is the need for better extension technology and the role of public/private and big company/local farmer partnerships.

Biocontrol of Plant Pathogens

Amongst a wide variety of presentations, Professor Alison Stewart (Lincoln University, New Zealand) detailed the importance of matching the mode of action of the biocontrol agent with the pathogen, using different sclerotial pathogens as examples, while Dr Yigal Elad (Volcani Centre, Israel) described current successes against Botrytis.

The 9th ICPP will be held in Turin, Italy on 24-29 August 2008.

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