UA00071 - Control and eradication of a parasitic weed, field trials.
|Project Start Date||1 July 2004|
|Project End Date||30 June 2007|
|Supervisor Name||David Coventry|
|Organisation||The University of Adelaide|
|Contact name||David Coventry|
This project was involved with control of branched broomrape (Orobanche ramose) in existing land use systems in the south western Murray Mallee of South Australia (SA). It was concerned with aspects of weed control using herbicides and understanding features of the weed's life cycle that may facilitate eradication of branched broomrape. The project team set up and began the task of identifying longevity of the seed in the soil so as to understand the duration of an eradication effort. The project was also involved with trialling a novel seed killing soil drench.
Several issues emerged from the six years of research invested in the control of the holoparasitic weed, branched broomrape. The presence of a parasite immediately presupposes the presence of suitable hosts. The control of a parasite is about understanding the agronomy, development and contribution of the hosts. With a parasitic weed, there need to be methods to control host weeds, in this case probably approx. 25 species, however not all are weeds of cereal crops and pastures. Although there is a good range of herbicides for cereal crops and some will control broomrape, this not always the case. For a weed/host complex to emerge and sustain itself indicates that previous weed control has been inadequate. Much effort has been placed on rotational crops in this project. Very few crops are grown in such a varied and semi-arid environment and herbicide protection from broomrape is extremely limited.
Herbicide recommendations will enable farmers to attain the necessary conditions for release from quarantine. In turn, Australian markets will be assured the threat that branched broomrape poses to production is extinguished.
This project was established to provide useful information to growers in the broomrape quarantine area as well as provide information for and input to strategies needed for eradication. Research personnel were required to consult with and when necessary, advise the Department of Water, Land and Biodiversity Conservation (DWLBC). Information was needed about herbicide protection of existing crops and pastures. Herbicides represent the cheapest method to prevent broomrape emergence, growth and maturity leading to seed set. Information was also needed about the duration of viability of broomrape seed in the soil.
Weeds are often suppressed but not killed by the usual herbicide regime and competition of the crop is needed to finally kill the weed. These conditions are not adequate in the case of a parasite where eradication is the goal. Herbicide technology is vested in companies that can gather the resources to develop, test, register and promote new molecules with widespread application. It is in the interests of Australian agriculture and agriculture in many other countries that more effort is made to find herbicides that will control branched broomrape in a range of crops and pastures. However, there is currently little interest in broomrape control.
It is true to say that the Australian weed science community and crop protection hierarchy have focused on more conventional weeds for many years. The brief period of research on branched broomrape in this country has done little more than address surface issues. Regard for the dynamics and development of host weeds, the persistence of some weeds in a semi-arid hostile cropping environment and containing spread are of equal importance in the longer term. If the phyto-sanitary implications of broomrape contamination are important to Australia's exports then a more rounded effort may be required to contain this weed.
|Published Date||28 February 2017|
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