Herbicide Resistant Weeds

GROUP G/9 RESISTANT HAIRY FLEABANE (Conyza bonariensis)
South Africa

Saturday, July 31, 2010

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Hairy Fleabane

1.	Introduction
2.	Level of Infestation
3.	Quick Statistics
4.	Notes about this biotype
5.	Academic Aspects
6.	R Hairy Fleabane Globally
7.	Fact Sheets and Literature
8.	Contributing Weed Scientists
9.	Acknowledgements
10.	Where to now?

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Introduction

Level of Infestation

Hairy Fleabane (Conyza bonariensis) is a dicot weed in the Asteraceae family. In South Africa this weed first evolved resistance to Group G/9 herbicides in 2003 and infests orchards, and vineyards. Group G/9 herbicides are known as Glycines (Inhibition of EPSP synthase). Research has shown that these particular biotypes are resistant to glyphosate and they may be cross-resistant to other Group G/9 herbicides.

Local weed scientists estimate that Group G/9 resistant Hairy Fleabane in South Africa infests 2-5 sites. They also estimate that there are 11-50 acres infested with Group G/9 resistant Hairy Fleabane.

The 'Group' letters/numbers that you see throughout this web site refer to the classification of herbicides by their mode of action. To see a full list of herbicides and HRAC herbicide classifications click here.

QUIK STATS ( last updated Aug 04, 2003 )
Common Name	Hairy Fleabane
Species	Conyza bonariensis
Group	Glycines (G/9)
Herbicides	glyphosate
Location	South Africa, Western Cape
Year	2003
Situation(s)	orchards, and vineyards
Sites	2-5
Acres Infested	11-50
Contributors	Andrew Cairns
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NOTES ABOUT THIS BIOTYPE

GENERAL

Andrew Cairns

Conyza bonariensis in the Western Cape.

In January 2003 reports were received from the Breede Valley (about 100km north east of Cape Town) of glyphosate failing to control Conyza bonariensis at registered dosage rates. Seed from plants growing in a deciduous fruit orchard in the area were collected and germinated in pots. The seedlings were subsequently transplanted into pots and a month later the plants were subjected to a dose response trial with glyphosate. A control population of the C. bonariensis derived from seed collected from a population of the weed growing at Stellenbosh University’s experimental farm, Welgevallen, was similarly treated. At the time of spraying, the plants had 10-12 leaves and were still in the rosette stage. The weeds were subjected to a range of glyphosate dosage rates viz. 0.36, 0.72, 1.08, 1.44, 2.16, 2.88, and 3.60 kg a.e. glyphosate ha^-1. Four replicates per treatment were used.

From the results of this dose response trial (Table 1), it is clear that the Breede Valley population was not controlled at all at the registered dosage rate (1.08kg a.e. glyphosate ha^-1) and only 17% of the weeds were controlled at twice the registered dose of glyphosate. The control (Welgevallen) population was fully controlled at all dosage rates above 0.36 kg a.e glyphosate ha^-1. The trial was rated 56 days after treatment.

Table 1. Dose response of two Western Cape populations of Conyza bonariensis to glyphosate.

	Control (%)
Treatment	Population
(kg a.e. glyphosate ha^-1)	Breede Valley	Welgevallen
0	0	0
0.36	0	50
0.72	0	100
1.08	0	100
1.44	0	100
2.16	17	100
2.88	83	100
3.60	94	100

Subsequent screening has identified 3 more glyphosate-resistant populations of C. bonariensis (all from the Breede Valley). Work is in progress to map the extent of glyphosate resistant populations of C. bonariensis in the Western Cape and to identify cost effective control strategies.

A.L.P. Cairns
Department of Agronomy
University of Stellenbosch

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ACADEMIC ASPECTS

Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Hairy Fleabane biotype with this Hairy Fleabane biotype have been used to confirm resistance. For further information on the tests conducted please contact the local weed scientists that provided this information.

Genetics

The genetic basis of resistance for this biotype is either unknown or has not been entered in the database. If you know anything about the genetic inheritance of this biotype please update the database.

Mechanism of Resistance

The mechanism of resistance for this biotype is either unknown or has not been entered in the database. If you know anything about the mechanism of resistance for this biotype then please update the database.

Relative Fitness

There is no record of differences in fitness or competitiveness of these resistant biotypes when compared to that of normal susceptible biotypes. If you have any information pertaining to the fitness of Group G/9 resistant Hairy Fleabane from South Africa please update the database.

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HERBICIDE RESISTANT HAIRY FLEABANE GLOBALLY
#	Country	Year	Sites	Acres	Mode of Action
1.	Brazil	2005	11-50	101-500	Glycines (G/9)
2.	Brazil	2005	6-10	51-100	Glycines (G/9)
3.	Colombia	2006	2-5	51-100	Glycines (G/9)
4.	Egypt	1989	unknown	unknown	Bipyridiliums (D/22)
5.	Israel	1993	2-5	101-500	Photosystem II inhibitors (C1/5)
6.	Israel	1993	2-5	101-500	ALS inhibitors (B/2)
7.	Israel	2005	51-100	1001-10000	Glycines (G/9)
8.	Japan	1989	6-10	1-5	Bipyridiliums (D/22)
9.	South Africa	2003	6-10	101-500	Bipyridiliums (D/22)
10.	South Africa	2003	2-5	11-50	Glycines (G/9)
11.	Spain	1987	2-5	11-50	Photosystem II inhibitors (C1/5)
12.	Spain	2004	6-10	1001-10000	Glycines (G/9)
13.	USA (California)	2007	2-5	unknown	Glycines (G/9)
14.	USA (California) Multiple Resistance	2009	2-5	unknown	Bipyridiliums (D/22) Glycines (G/9)

FACT SHEETS AND OTHER LITERATURE	Format
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Scientific Abstracts on Herbicide Resistant Conyza bonariensis
Interactions of cations with paraquat in leaf sections of resistant and sensitive biotypes of Conyza bonariensis.
Norman, M. A. and E. Fuerst P. 1997. Interactions of cations with paraquat in leaf sections of resistant and sensitive biotypes of Conyza bonariensis. Pesticide Biochemistry and Physiology. 57: 181-191.
Response of beans and hairy fleabane leaves to ozone and paraquat with and without the antiozonant, ethylenediurea.
Mersie, W., H. A. Norman, and P. Pillai. 1994. Response of beans and hairy fleabane leaves to ozone and paraquat with and without the antiozonant, ethylenediurea. Environmental and Experimental Botany. 34: 379-383.
Constitutive variation of ascorbate peroxidase activity during development parallels that of superoxide dismutase and glutathione reductase in paraquat-resistant Conyza.
Ye, B. and J. Gressel. 1994. Constitutive variation of ascorbate peroxidase activity during development parallels that of superoxide dismutase and glutathione reductase in paraquat-resistant Conyza. Plant Science Limerick. 102: 147-151.
Developmental variability of photooxidative stress tolerance in paraquat-resistant Conyza.
Amsellem, Z., M. A. K. Jansen, A. R. J. Driesenaar, and J. Gressel. 1993. Developmental variability of photooxidative stress tolerance in paraquat-resistant Conyza. Plant Physiology. 103: 1097-1106.
Evaluation of paraquat resistance mechanisms in Conyza.
Norman, M. A., E. P. Fuerst, R. J. Smeda, and K. C. Vaughn. 1993. Evaluation of paraquat resistance mechanisms in Conyza. Pesticide Biochemistry and Physiology. 46: 236-249.
Photosynthetic activity and chloroplast structural characteristics in triazine-resistant biotypes of three weed species.
Prado, R. de, C. Dominguez, I. Rodriguez, M. Tena, and R. De Prado. 1992. Photosynthetic activity and chloroplast structural characteristics in triazine-resistant biotypes of three weed species. Physiologia Plantarum. 84: 477-485.
Resistance to the herbicide paraquat and increased tolerance to photoinhibition are not correlated in several weed species.
Preston, C., J. A. M. Holtum, and S. B. Powles. 1991. Resistance to the herbicide paraquat and increased tolerance to photoinhibition are not correlated in several weed species. Plant Physiology. 96: 314-318.
Characterization of triazine-resistant biotypes of common lambsquarters (Chenopodium album), hairy fleabane (Conyza bonaeriensis), and yellow foxtail (Setaria glauca) found in Spain.
Prado, R. de, C. Dominguez, and M. Tena. 1989. Characterization of triazine-resistant biotypes of common lambsquarters (Chenopodium album), hairy fleabane (Conyza bonaeriensis), and yellow foxtail (Setaria glauca) found in Spain. Weed Science. 37: 1-4.
Increased tolerance to photoinhibitory light in paraquat-resistant Conyza bonariensis measured by photoacoustic spectroscopy and 14CO2-fixation.
Jansen, M. A. K., Y. Shaaltiel, D. Kazzes, O. Canaani, S. Malkin, and J. Gressel. 1989. Increased tolerance to photoinhibitory light in paraquat-resistant Conyza bonariensis measured by photoacoustic spectroscopy and 14CO2-fixation. Plant Physiology. 91: 1174-1178.
Triazine-resistant weeds found in Spain.
De Prado, R., C. Dominguez, M. Tena, R. Prado de, R. Cavalloro (ed.), and G. Noye (ed.). 1989. Triazine-resistant weeds found in Spain. Importance and perspectives on herbicide-resistant weeds. Proceedings of a meeting of the EC Experts' Group, Tollose, Denmark, 15-17 November 1988. 11561: 67-79.
Lack of cross-resistance of paraquat-resistant hairy fleabane (Conyza bonariensis) to other toxic oxygen generators indicates enzymatic protection is not the resistance mechanism.
Vaughn, K. C., M. A. Vaughan, and P. Camilleri. 1989. Lack of cross-resistance of paraquat-resistant hairy fleabane (Conyza bonariensis) to other toxic oxygen generators indicates enzymatic protection is not the resistance mechanism. Weed Science. 37: 5-11.
Dominant pleiotropy controls enzymes co-segregating with paraquat resistance in Conyza bonariensis.
Shaaltiel, Y., N. H. Chua, S. Gepstein, and J. Gressel. 1988. Dominant pleiotropy controls enzymes co-segregating with paraquat resistance in Conyza bonariensis. Theoretical and Applied Genetics. 75: 850-856.
Cross tolerance to herbicidal and environmental oxidants of plant biotypes tolerant to paraquat, sulfur dioxide, and ozone.
Shaaltiel, Y., A. Glazer, P. F. Bocion, and J. Gressel. 1988. Cross tolerance to herbicidal and environmental oxidants of plant biotypes tolerant to paraquat, sulfur dioxide, and ozone. Pesticide Biochemistry and Physiology. 31: 13-23.
Kinetic analysis of resistance to paraquat in Conyza. Evidence that paraquat transiently inhibits leaf chloroplast reactions in resistant plants.
Shaaltiel, Y. and J. Gressel. 1987. Kinetic analysis of resistance to paraquat in Conyza. Evidence that paraquat transiently inhibits leaf chloroplast reactions in resistant plants. Plant Physiology. 85: 869-871.
Biochemical analysis of paraquat resistance in Conyza leads to pinpointing synergists for oxidant generating herbicides.
Shaaltiel, Y., J. Gressel, R. Greenhalgh (ed.), and T. R. Roberts. 1987. Biochemical analysis of paraquat resistance in Conyza leads to pinpointing synergists for oxidant generating herbicides. Proceedings of the 6th international congress of pesticide chemistry, Pesticide science and biotechnology. : 183-186.
Structural and physiological studies of paraquat-resistant Conyza.
Vaughn, K. C. and E. P. Fuerst. 1985. Structural and physiological studies of paraquat-resistant Conyza. Pesticide Biochemistry and Physiology. 24: 86-94.
Paraquat resistance in Conyza.
Fuerst, E. P., H. Y. Nakatani, A. D. Dodge, D. Penner, and C. J. Arntzen. 1985. Paraquat resistance in Conyza. Plant Physiology. 77: 984-989.
Mechanism of paraquat tolerance in Conyza bonariensis and in Lolium perenne.
Shaaltiel, Y. and J. Gressel. 1985. Mechanism of paraquat tolerance in Conyza bonariensis and in Lolium perenne. Phytoparasitica. 13: 232.

CONTRIBUTING WEED SCIENTISTS

ANDREW CAIRNS	Edit
University of Stellenbosch Department of Agronomy Private bag X1 Matieland, 7602 South Africa Email Andrew Cairns

Acknowledgements

Where to now?

The Herbicide Resistance Action Committee, the Weed Science Society of America, and weed scientists in South Africa have been instrumental in providing you this information. Particular thanks is given to Andrew Cairns for providing detailed information.

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