Management Information
Mechanical: The spread of B. tournefortii can be reduced by controlling it along roads, which provide corridors for rapid invasion into new habitats. In small areas Sahara mustard can be eradicated by pulling plants before they mature seed. This is most effective in new invasions where a seed bank has not been established (Invaders of the Sonoran Desert Region, Undated). Sanders and Minnich (2000) report that, "Hand pulling of B. tournefortii might be effective in limited areas when seed pools have been suppressed. Planned burns may not be a useful option. Although fires cause high seed loss, stem densities reach pre-burn levels within one or two growing seasons. Partial seed survival after fire may be related to its hard seed coat. B. tournefortii is closely related to a number of important vegetable crops, so it will be difficult to find an agent that will attack this plant but not damage food crops. Even the possibility of transfer of a control agent to a valuable food crop may create political pressures that could prevent importation of the agent. Since B. tournefortii establishes from a seed bank, it is doubtful that grazing could suppress the spread of this annual. The establishment of dense cover of exotic annual grasses apparently suppresses this species." Chemical: In selected areas herbicide treatment may be effective. Sahara mustard tends to be the first annual to germinate after a rain, so early treatment may reduce its abundance and allow later-germinating natives to establish (Invaders of the Sonoran desert, Undated). ALS inhibitor herbicides are used widely "because of their low use rates, high efficacy, low mammalian toxicity and good selectivity in over 12 major crops" (Brown and Cotterman, 1994 in Heap, 1997). However, at least 33 ALS-inhibitor resistant weed species have been recorded. B. tournefortii was identified to be resistant to Chlorsulfuron in 1992 in Australia (Heap, 1997).
In an Australian study by Adkins et al. (1997) the authors determined that B. tournefortii and other winter weeds were still susceptible to chlorsulfuron, despite fears that they may be becomming more resistant with continued use. Yu et al. (2003) reports that, "An African mustard Brassica tournefortii (Gouan.) biotype with a Pro to Ala substitution also was reported as highly resistant to SU and TP [herbicides] but not to IM herbicides (Boutsalis et al. 1999, in Yu et al.
2003)." Biological: Invaders of the Sonoran desert (Undated) state that "It is unlikely that a biological agent, if found, would be approved because many important crop plants are in the genus Brassica (e.g., cabbage, cauliflower, broccoli, brussels sprouts). There are also numerous native mustards that might be threatened by a biological agent".
Location Specific Management InformationAustralia
In an Australian study by Adkins et al. (1997) the authors determined that B. tournefortii and other winter weeds were still susceptible to chlorsulfuron, despite fears that they may be becomming more resistant with continued use.
Management Resources/Links
1. Brooks, M.L., and D.A. Pyke. 2001. Invasive plants and fire in the deserts of North America. Pages 1–14 in K.E.M. Galley
and T.P. Wilson (eds.). Proceedings of the Invasive Species Workshop: the Role of Fire in the Control and Spread of Invasive Species.
Fire Conference 2000: the First National Congress on Fire Ecology, Prevention, and Management. Miscellaneous Publication No. 11,
Tall Timbers Research Station, Tallahassee, FL. 2. Brown, H. M. & Cotterman, J. C., 1994. Recent advances in
sulfonylurea herbicides. In Chemistry of Plant Protection,
Springer-Verlag, Berlin & Heidelberg, 10 49-81. 4. Heap, Ian M, 1997. The Occurrence of Herbicide-Resistant Weeds Worldwide. Pesticide Science 51, 235-243
7. Obbens, F J ., R W Davis & L W Sage., 2001. Vegetation, flora and recommendations for conservation management of Jingaring Nature Reserve: A “botanical gem” in the Western Australian wheat-belt. Journal of the Royal Society of Western Australia, 84: 53-61
9. Sanders, A., and R. Minnich. 2000. Brassica tournefortii. California Invasive Plant Council, Berkeley, CA.
Summary: Information on description, economic importance, distribution, habitat, history, growth, and impacts and management of species.
Available from: http://ucce.ucdavis.edu/datastore/detailreport.cfm?usernumber=12&surveynumber=182 [Accessed 10 February 2004] 10. Van Devender, Thomas R., Richard S. Felger., & Alberto Búrquez M., 1997. Exotic Plants in the Sonoran Desert Region,
Arizona and Sonora. California Exotic Pest Plant Council 1997 Symposium Proceedings
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