Herbicide Resistant Weeds

GROUP G/9 RESISTANT RIGID RYEGRASS (Lolium rigidum)
Australia: Victoria

Tuesday, February 09, 2010

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Rigid Ryegrass

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

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Introduction

Level of Infestation

Rigid Ryegrass (Lolium rigidum) is a monocot weed in the Poaceae family. In Victoria this weed first evolved resistance to Group G/9 herbicides in 1996 and infests cropland, grain sorghum, and wheat. 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 Rigid Ryegrass in Victoria infests 2-5 sites. They also estimate that there are 11-50 acres infested with Group G/9 resistant Rigid Ryegrass.

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 Nov 20, 2000 )
Common Name	Rigid Ryegrass
Species	Lolium rigidum
Group	Glycines (G/9)
Herbicides	glyphosate
Location	Australia, Victoria
Year	1996
Situation(s)	cropland, grain sorghum, and wheat
Sites	2-5
Acres Infested	11-50
Contributors	Jim Dellow, Jim Pratley, and Andrew Storrie
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NOTES ABOUT THIS BIOTYPE

AREAS FOUND

Jim Pratley

The first weed population to evolve glyphosate resistance under field conditions. Second population found in 1997 in apple orchard of NSW and has been published in Weed Science by Steve Powles.

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GENERAL

Jim Pratley

Three sites now, including one reported by Andrew Storrie. 1998 Glyphosate and fop resistance, southern Liverpool plains (NSW). One property, 10 ha in patches. Glasshouse tested (CSU Wagga). Wheat-fallow-sorghum rotation 30-40 applications of 0.4 to 2 L/ha glyphosate (450 g ai) over 15 years.

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ACADEMIC ASPECTS

Confirmation Tests

Field, and Greenhouse trials comparing a known susceptible Rigid Ryegrass biotype with this Rigid Ryegrass 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 Rigid Ryegrass from Victoria please update the database.

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HERBICIDE RESISTANT RIGID RYEGRASS GLOBALLY
#	Country	Year	Sites	Acres	Mode of Action
1.	Australia (Western Australia) Multiple Resistance	1982	1001-10000	2-5 million	ACCase inhibitors (A/1) ALS inhibitors (B/2) Dinitroanilines and others (K1/3)
2.	Australia (South Australia) Multiple Resistance	1982	1001-10000	10001-100000	ACCase inhibitors (A/1) ALS inhibitors (B/2) Triazoles, ureas, isoxazolidiones (F3/11) Dinitroanilines and others (K1/3) Mitosis inhibitors (K2/23) Chloroacetamides and others (K3/15) Thiocarbamates and others (N/8)
3.	Australia (Western Australia)	1984	501-1000	1001-10000	ALS inhibitors (B/2)
4.	Australia (Western Australia)	1984	6-10	11-50	Dinitroanilines and others (K1/3)
5.	Australia (South Australia)	1984	1	1-5	Chloroacetamides and others (K3/15)
6.	Australia (Victoria) Multiple Resistance	1984	1001-10000	10001-100000	ACCase inhibitors (A/1) ALS inhibitors (B/2) Dinitroanilines and others (K1/3)
7.	Australia (New South Wales ) Multiple Resistance	1985	501-1000	10001-100000	ACCase inhibitors (A/1) ALS inhibitors (B/2) Dinitroanilines and others (K1/3)
8.	Australia (Western Australia)	1988	2-5	51-100	Triazoles, ureas, isoxazolidiones (F3/11)
9.	Australia (Western Australia)	1988	11-50	101-500	Photosystem II inhibitors (C1/5)
10.	Australia (South Australia)	1994	101-500	10001-100000	Dinitroanilines and others (K1/3)
11.	Australia (Victoria)	1996	2-5	11-50	Glycines (G/9)
12.	Australia (New South Wales )	1997	11-50	1001-10000	Glycines (G/9)
13.	Australia (Victoria) Multiple Resistance	1999	1	6-10	ACCase inhibitors (A/1) ALS inhibitors (B/2) Glycines (G/9) Dinitroanilines and others (K1/3)
14.	Australia (South Australia)	2000	11-50	51-100	Glycines (G/9)
15.	Australia (Western Australia)	2003	1	1-5	Glycines (G/9)
16.	Chile	1997	11-50	1001-10000	ACCase inhibitors (A/1)
17.	Chile Multiple Resistance	2003	1	51-100	ACCase inhibitors (A/1) ALS inhibitors (B/2)
18.	Chile Multiple Resistance	2006	1	51-100	ACCase inhibitors (A/1) ALS inhibitors (B/2)
19.	Chile Multiple Resistance	2006	1	51-100	ACCase inhibitors (A/1) ALS inhibitors (B/2)
20.	Chile Multiple Resistance	2006	1	51-100	ACCase inhibitors (A/1) ALS inhibitors (B/2)
21.	France	1993	unknown	unknown	ACCase inhibitors (A/1)
22.	France	2005	6-10	501-1000	Glycines (G/9)
23.	France	2005	6-10	501-1000	Glycines (G/9)
24.	France	2006	11-50	101-500	ALS inhibitors (B/2)
25.	Greece	1997	1	6-10	ACCase inhibitors (A/1)
26.	Iran	2007	11-50	101-500	ACCase inhibitors (A/1)
27.	Israel	1979	101-500	1001-10000	Photosystem II inhibitors (C1/5)
28.	Israel	1998	1	1-5	ACCase inhibitors (A/1)
29.	Italy	2007	2-5	501-1000	Glycines (G/9)
30.	Saudi Arabia	1992	101-500	10001-100000	ACCase inhibitors (A/1)
31.	South Africa Multiple Resistance	1993	101-500	1001-10000	ACCase inhibitors (A/1) ALS inhibitors (B/2)
32.	South Africa	2001	11-50	501-1000	Glycines (G/9)
33.	South Africa	2002	6-10	101-500	Bipyridiliums (D/22)
34.	South Africa Multiple Resistance	2003	1	6-10	ACCase inhibitors (A/1) Bipyridiliums (D/22) Glycines (G/9)
35.	Spain Multiple Resistance	1992	11-50	51-100	ACCase inhibitors (A/1) Ureas and amides (C2/7)
36.	Spain	1992	11-50	51-100	ACCase inhibitors (A/1)
37.	Spain	1992	11-50	51-100	Photosystem II inhibitors (C1/5)
38.	Spain	2006	2-5	101-500	Glycines (G/9)
39.	Tunisia	1996	11-50	10001-100000	ACCase inhibitors (A/1)
40.	USA (California)	1998	11-50	1001-10000	Glycines (G/9)

FACT SHEETS AND OTHER LITERATURE	Format
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Scientific Abstracts on Herbicide Resistant Lolium rigidum
Mutations of the ALS gene endowing resistance to ALS-inhibiting herbicides in Lolium rigidum populations.
Yu, Q., H. Han and S. B. Powles. 2008. Mutations of the ALS gene endowing resistance to ALS-inhibiting herbicides in Lolium rigidum populations. Pest Management Science. 64: 1229-1236.
Molecular basis of multiple resistance to ACCase-inhibiting and ALS-inhibiting herbicides in Lolium rigidum.
Tan, M. K., C. Preston, and G. X. Wang. 2007. Molecular basis of multiple resistance to ACCase-inhibiting and ALS-inhibiting herbicides in Lolium rigidum. Weed Research. 47: 534-541.
Diclofop-methyl resistance in populations of Lolium spp. from central Italy.
Bravin, F., G. Zanin and C. Preston 2001. Diclofop-methyl resistance in populations of Lolium spp. from central Italy. Weed Research. 41: 49-58.
Resistance to diclofop-methyl in two Lolium spp. populations from Italy: studies on the mechanism of resistance.
Bravin, F., G. Zanin and C. Preston 2001. Resistance to diclofop-methyl in two Lolium spp. populations from Italy: studies on the mechanism of resistance. Weed Research. 41: 461-473.
Resistance to glyphosate in a population of Lolium rigidum.
Hawkes, T. R., D. Lorraine Collwill F., P. Williams H., S. Warner A.J., P. Sutton B., S. Powles B., and C. Preston. 1999. Resistance to glyphosate in a population of Lolium rigidum. Plant biotechnology and in vitro biology in the 21st century. Proceedings of the IXth International Congress of the International Association of Plant Tissue Culture and Biotechnology, Jerusalem, Israel, 14-19 June 1998. : 491-494.
Evaluation of Lolium rigidum biotypes resistance to chlorsulfuron: useful parameters.
Carrera, N. de la, M. Villarroya, M. Chueca C., and J. Garcia Baudin M. 1999. Evaluation of Lolium rigidum biotypes resistance to chlorsulfuron: useful parameters. 1999 Brighton crop protection conference: weeds. Proceedings of an international conference, Brighton, UK, 15-18 November 1999. 1: 153-158.
Effect of malathion on resistance to soil-applied herbicides in a population of rigid ryegrass (Lolium rigidum).
Tardif, F. J. and S. Powles B. 1999. Effect of malathion on resistance to soil-applied herbicides in a population of rigid ryegrass (Lolium rigidum). Weed Science. 47: 258-261.
Resistance to glyphosate in Lolium rigidum.
Lorraine Colwill, D. F., T. Hawkes R., P. Williams H., S. Warner A.J., P. Sutton B., S. Powles B., and C. Preston. 1999. Resistance to glyphosate in Lolium rigidum. Pesticide Science. 55: 489-491.
Phytotoxicity of different glyphosate formulations in simazine- resistant and -susceptible Lolium rigidum biotypes.
Gonzalez Gutierrez, J. and R. Prado A. de. 1998. Phytotoxicity of different glyphosate formulations in simazine- resistant and -susceptible Lolium rigidum biotypes. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent. 63: 303-308.
Weed management in south western Australian farming systems.
Bowran, D. G. 1998. Weed management in south western Australian farming systems. Comptes-rendus 6eme symposium mediterraneen EWRS, Montpellier, France, 13-15 mai 1998. : 273-280.
Biochemical and physiological resistance mechanism to diclofop-methyl in Lolium rigidum.
Prado, J. L. de, M. Osuna D., R. Shimabukuro H., and R. Prado de. 1998. Biochemical and physiological resistance mechanism to diclofop-methyl in Lolium rigidum. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent. 63: 681-690.
Success from adversity: herbicide resistance can drive changes to sustainable weed management systems.
Powles, S. B. 1997. Success from adversity: herbicide resistance can drive changes to sustainable weed management systems. 1997 Brighton crop protection conference: weeds. Proceedings of an international conference, Brighton, UK, 17-20 November 1997. 3: 1119-1126.
Resistance to substituted urea herbicides in Lolium rigidum biotypes.
Prado, R. de, J. Prado L. de, and J. Menendez. 1997. Resistance to substituted urea herbicides in Lolium rigidum biotypes. Pesticide Biochemistry and Physiology. 57: 126-136.
Light-dependent enhanced metabolism of chlorotoluron in a substituted urea herbicide-resistant biotype of Lolium rigidum Gaud.
Preston, C. and S. B. Powles. 1997. Light-dependent enhanced metabolism of chlorotoluron in a substituted urea herbicide-resistant biotype of Lolium rigidum Gaud. Planta. 201: 202-208.
Efficacy of cultural control methods for combating herbicide- resistant Lolium rigidum.
Gill, G. S. and J. Holmes E. 1997. Efficacy of cultural control methods for combating herbicide- resistant Lolium rigidum. Pesticide Science. 51: 352-358.
Control of a simazine-resistant Lolium rigidum biotype at low rates of different glyphosate formulations.
Gonzalez Gutierrez, J. and R. Prado de. 1997. Control of a simazine-resistant Lolium rigidum biotype at low rates of different glyphosate formulations. Proceedings of the 1997 congress of the Spanish Weed Science Society, Valencia, Spain, 24-26 November 1997. : 83-87.
Development of new reliable quick tests and state of grass-weed herbicide resistance in France.
Letouze, A., J. Gasquez, D. Vaccara, D. Orlando, J. Leterrier L., C. Roy, and E. Bouvard Derieux. 1997. Development of new reliable quick tests and state of grass-weed herbicide resistance in France. 1997 Brighton crop protection conference: weeds. Proceedings of an international conference, Brighton, UK, 17-20 November 1997. 1: 325-330.
Chemical management of annual ryegrass.
Matthews, J. M. 1996. Chemical management of annual ryegrass. Plant Protection Quarterly. 11: 200-202.
Economic factors influencing control and management decisions for annual grasses in crops and pastures.
Moore, J., P. Dowling (ed.), and R. Medd. 1996. Economic factors influencing control and management decisions for annual grasses in crops and pastures. Plant Protection Quarterly. 11: 217-222.
Chemical management of annual ryegrass. Wild oats, annual ryegreass and vulpia.
Matthews, J. M., P. Dowling (ed.), and R. Medd. 1996. Chemical management of annual ryegrass. Wild oats, annual ryegreass and vulpia. Plant Protection Quarterly. 11: 200-202.
Germination, growth, and development of herbicide resistant and susceptible populations of rigid ryegrass (Lolium rigidum).
Gill, G. S., R. D. Cousens, and M. R. Allan. 1996. Germination, growth, and development of herbicide resistant and susceptible populations of rigid ryegrass (Lolium rigidum). Weed Science. 44: 252-256.
Why annual ryegrass is a problem in Australian agriculture.
Gill, G. S., P. Dowling (ed.), and R. Medd. 1996. Why annual ryegrass is a problem in Australian agriculture. Plant Protection Quarterly. 11: 193-195.
Economic evaluation of strategies for management of herbicide resistance.
Gorddard, R. J., D. J. Pannell, and G. Hertzler. 1996. Economic evaluation of strategies for management of herbicide resistance. Agricultural Systems. 51: 281-298.
Developments in grass weed management in a mixed farming situation.
Butler, B. J., P. Dowling (ed.), and R. Medd. 1996. Developments in grass weed management in a mixed farming situation. Wild oats, annual ryegreass and vulpia. Proceedings of a workshop held at Orange 1996. New South Wales, Australia, on 26-27 March 1996. Plant-Protection-Quarterly. 11: 222.
Resistance to acetyl-coenzyme A carboxylase-inhibiting herbicides endowed by a single major gene encoding a resistant target site in a biotype of Lolium rigidum.
Tardif, F. J., C. Preston, J. A. M. Holtum, and S. B. Powles. 1996. Resistance to acetyl-coenzyme A carboxylase-inhibiting herbicides endowed by a single major gene encoding a resistant target site in a biotype of Lolium rigidum. Australian Journal of Plant Physiology. 23: 15-23.
Economic issues in management of herbicide-resistant weeds.
Schmidt, C. P. and D. J. Pannell. 1996. Economic issues in management of herbicide-resistant weeds. Review of Marketing and Agricultural Economics. 64: 301-308.
The role and value of herbicide-resistant lupins in Western Australian agriculture.
Schmidt, C. P. and D. J. Pannell. 1996. The role and value of herbicide-resistant lupins in Western Australian agriculture. Crop Protection. 15: 539-548.
Approaches to assess the frequency of resistance development to new herbicides.
Subramanian, M. V., P. Bernasconi, F. D. Hess, H. Brown (ed.), G. W. Cussans (ed.), M. D. Devine (ed.), S. O. Duke (ed.), C. Fernandez Quintanilla (ed.), A. Helweg (ed.), R. E. Labrada (ed.), M. Landes (ed.), P. Kudsk (ed.), and J. C. Streibig. 1996. Approaches to assess the frequency of resistance development to new herbicides. Proceedings of the second international weed control congress, Copenhagen, Denmark, 25-28 June 1996. 1-4: 447-453.
Multiple resistance to dissimilar herbicide chemistries in a biotype of Lolium rigidum due to enhanced activity of several herbicide degrading enzymes.
Preston, C., F. J. Tardif, J. T. Christopher, and S. B. Powles. 1996. Multiple resistance to dissimilar herbicide chemistries in a biotype of Lolium rigidum due to enhanced activity of several herbicide degrading enzymes. Pesticide Biochemistry and Physiology. 54: 123-134.
Integrated weed management for the control of herbicide resistant annual ryegrass (Lolium rigidum).
Powles, S. B., J. M. Matthews, H. Brown (ed.), G. W. Cussans (ed.), M. D. Devine (ed.), S. O. Duke (ed.), C. Fernandez Quintanilla (ed.), A. Helweg (ed.), R. E. Labrada (ed.), M. Landes (ed.), P. Kudsk (ed.), and J. C. Streibig. 1996. Integrated weed management for the control of herbicide resistant annual ryegrass (Lolium rigidum). Proceedings of the second international weed control congress, Copenhagen, Denmark, 25-28 June 1996. 1-4: 407-414.
Residual activity of chlorthal-dimethyl, metribuzin and prometryn determined by bioassays in field trials.
Americanos, P. G. and N. A. Vouzounis. 1995. Residual activity of chlorthal-dimethyl, metribuzin and prometryn determined by bioassays in field trials. Technical Bulletin Cyprus Agricultural Research Institute. 167: 15.
An optimal control model for integrated weed management under herbicide resistance.
Gorddard, R. J., D. J. Pannell, and G. Hertzler. 1995. An optimal control model for integrated weed management under herbicide resistance. Australian Journal of Agricultural Economics. 39: 71-87.
Development of herbicide resistance in annual ryegrass populations (Lolium rigidum Gaud.) in the cropping belt of Western Australia.
Gill, G. S. 1995. Development of herbicide resistance in annual ryegrass populations (Lolium rigidum Gaud.) in the cropping belt of Western Australia. Australian Journal of Experimental Agriculture. 35: 67-72.
Dinitroaniline herbicide resistance in rigid ryegrass (Lolium rigidum).
McAlister, F. M., J. A. M. Holtum, and S. B. Powles. 1995. Dinitroaniline herbicide resistance in rigid ryegrass (Lolium rigidum). Weed Science. 43: 55-62.
Recovery of transmembrane potentials in plants resistant to aryloxyphenoxypropanoate herbicides: a phenomenon awaiting explanation.
Holtum, J. A. M., R. E. Hausler, M. D. Devine, and S. B. Powles. 1994. Recovery of transmembrane potentials in plants resistant to aryloxyphenoxypropanoate herbicides: a phenomenon awaiting explanation. Weed Science. 42: 293-301.
Mechanisms of cross and multiple herbicide resistance in Alopecurus myosuroides and Lolium rigidum.
Hall, L. M., F. J. Tardif, and S. B. Powles. 1994. Mechanisms of cross and multiple herbicide resistance in Alopecurus myosuroides and Lolium rigidum. Herbicide resistance workshop, Edmonton, Alberta, Canada, 9-10 December 1993. Phytoprotection. 75: 17-23.
Relationship between herbicide resistance in Lolium rigidum and populations of Anguina funesta, the nematode vector in annual ryegrass toxicity.
Riley, I. T. and G. S. Gill. 1994. Relationship between herbicide resistance in Lolium rigidum and populations of Anguina funesta, the nematode vector in annual ryegrass toxicity. Australian Journal of Experimental Agriculture. 34: 633-635.
Chloroacetamide resistance in rigid ryegrass (Lolium rigidum).
Burnet, M. W. M., A. R. Barr, and S. B. Powles. 1994. Chloroacetamide resistance in rigid ryegrass (Lolium rigidum). Weed Science. 42: 153-157.
Identification of two mechanisms of sulfonylurea resistance within one population of rigid ryegrass (Lolium rigidum) using a selective germination medium.
Burnet, M. W. M., J. T. Christopher, J. A. M. Holtum, and S. B. Powles. 1994. Identification of two mechanisms of sulfonylurea resistance within one population of rigid ryegrass (Lolium rigidum) using a selective germination medium. Weed Science. 42: 468-473.
Resistance to nine herbicide classes in a population of rigid ryegrass (Lolium rigidum).
Burnet, M. W. M., Q. Hart, J. A. M. Holtum, and S. B. Powles. 1994. Resistance to nine herbicide classes in a population of rigid ryegrass (Lolium rigidum). Weed Science. 42: 369-377.
Evidence against a direct membrane effect in the mechanism of action of graminicides.
Tomaso, J. M. di and J. M. Di Tomaso. 1994. Evidence against a direct membrane effect in the mechanism of action of graminicides. Weed Science. 42: 302-309.
Malathion antagonizes metabolism-based chlorsulfuron resistance in Lolium rigidum.
Christopher, J. T., C. Preston, and S. B. Powles. 1994. Malathion antagonizes metabolism-based chlorsulfuron resistance in Lolium rigidum. Pesticide Biochemistry and Physiology. 49: 172-182.
Herbicide multiple-resistance in a Lolium rigidum biotype is endowed by multiple mechanisms: isolation of a subset with resistant acetyl-CoA carboxylase.
Tardif, F. J. and S. B. Powles. 1994. Herbicide multiple-resistance in a Lolium rigidum biotype is endowed by multiple mechanisms: isolation of a subset with resistant acetyl-CoA carboxylase. Physiologia Plantarum. 91: 488-494.
Target site-based resistance to herbicides inhibiting acetyl-CoA carboxylase.
Tardif, F. J. and S. B. Powles. 1993. Target site-based resistance to herbicides inhibiting acetyl-CoA carboxylase. Brighton crop protection conference, weeds. Proceedings of an international conference, Brighton, UK, 22-25 November 1993. 2: 533-540.
Occurrence of a herbicide-resistant acetyl-coenzyme A carboxylase mutant in annual ryegrass (Lolium rigidum) selected by sethoxydim.
Tardif, F. J., J. A. M. Holtum, and S. B. Powles. 1993. Occurrence of a herbicide-resistant acetyl-coenzyme A carboxylase mutant in annual ryegrass (Lolium rigidum) selected by sethoxydim. Planta. 190: 176-181.
Cross resistance to aryloxyphenoxypropanoates and imidazolinones in a Lolium rigidum resistant to diclofop-methyl.
Dominguez, C., M. A. Medina, S. Borrero, R. Prado de, and R. De Prado. 1993. Cross resistance to aryloxyphenoxypropanoates and imidazolinones in a Lolium rigidum resistant to diclofop-methyl. Proceedings of the 1993 Congress of the Spanish Weed Science Society, Lugo, Spain, 1-3 December 1993. : 254-258.
Membrane response to diclofop acid is pH dependent and is regulated by the protonated form of the herbicide in roots of pea and resistant and susceptible rigid ryegrass.
DiTomaso, J. M. 1993. Membrane response to diclofop acid is pH dependent and is regulated by the protonated form of the herbicide in roots of pea and resistant and susceptible rigid ryegrass. Plant Physiology. 102: 1331-1336.
Increased detoxification is a mechanism of simazine resistance in Lolium rigidum.
Burnet, M. W. M., B. R. Loveys, J. A. M. Holtum, and S. B. Powles. 1993. Increased detoxification is a mechanism of simazine resistance in Lolium rigidum. Pesticide Biochemistry and Physiology. 46: 207-218.
A mechanism of chlorotoluron resistance in Lolium rigidum.
Burnet, M. W. M., B. R. Loveys, J. A. M. Holtum, and S. B. Powles. 1993. A mechanism of chlorotoluron resistance in Lolium rigidum. Planta. 190: 182-189.
Herbicide resistance and cytochrome P-450.
Hyde, R. J., A. K. Cheriton, D. L. Hallahan, and J. R. Bowyer. 1993. Herbicide resistance and cytochrome P-450. Brighton crop protection conference, weeds. Proceedings of an international conference, Brighton, UK, 22-25 November 1993. 2: 549-545.
Herbicide resistance in annual ryegrass in the cropping belt of Western Australia - a case for integrated weed management.
Gill, G. S. and A. J. Diggle. 1993. Herbicide resistance in annual ryegrass in the cropping belt of Western Australia - a case for integrated weed management. Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993. 1: 203-207.
Pollen expression of herbicide target site resistance genes in annual ryegrass (Lolium rigidum).
Richter, J. and S. B. Powles. 1993. Pollen expression of herbicide target site resistance genes in annual ryegrass (Lolium rigidum). Plant Physiology. 102: 1037-1041.
Multiple herbicide resistance in annual ryegrass (Lolium rigidum). A driving force for integrated weed management.
Powles, S. B. 1993. Multiple herbicide resistance in annual ryegrass (Lolium rigidum). A driving force for integrated weed management. Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993. 1: 189-194.
International organization for resistant pest management (IORPM) - a step toward rational resistance management recommendations.
Lebaron, H. M., J. Gressel, B. C. Smale, and D. M. Horne. 1992. International organization for resistant pest management (IORPM) - a step toward rational resistance management recommendations. Weed Technology. 6: 765-770.
Sulfonylurea resistance in annual ryegrass (Lolium rigidum) in Australia.
Christopher, J. T., M. Burnet, S. B. Powles, J. A. M. Holtum, and D. R. Liljegren. 1992. Sulfonylurea resistance in annual ryegrass (Lolium rigidum) in Australia. Proceedings of the 1st International Weed Control Congress. 2: 126-128.
Resistance to acetolactate synthase-inhibiting herbicides in annual ryegrass (Lolium rigidum) involves at least two mechanisms.
Christopher, J. T., S. B. Powles, and J. A. M. Holtum. 1992. Resistance to acetolactate synthase-inhibiting herbicides in annual ryegrass (Lolium rigidum) involves at least two mechanisms. Plant Physiology. 100: 1909-1913.
Tolerance of Lolium rigidum to diclofop-methyl and isoproturon.
Medina, M. A., J. L. Prado de, A. Taberner, E. Romera, J. Menendez, R. Prado de, J. L. De Prado, and R. De Prado. 1992. Tolerance of Lolium rigidum to diclofop-methyl and isoproturon. IXe Colloque international sur la biologie des mauvaises herbes, 16-18 September 1992, Dijon, France. : 471-476.
Aspects of the population dynamics of selection for herbicide resistance in Lolium rigidum (Gaud).
Matthews, J. M. and S. B. Powles. 1992. Aspects of the population dynamics of selection for herbicide resistance in Lolium rigidum (Gaud). Proceedings of the 1st International Weed Control Congress. 2: 318-320.
Rapid metabolic inactivation is the basis for cross-resistance to chlorsulfuron in diclofop-methyl-resistant rigid ryegrass (Lolium rigidum) biotype SR4/84.
Cotterman, J. C. and L. L. Saari. 1992. Rapid metabolic inactivation is the basis for cross-resistance to chlorsulfuron in diclofop-methyl-resistant rigid ryegrass (Lolium rigidum) biotype SR4/84. Pesticide Biochemistry and Physiology. 43: 182-192.
Agrichemical industry initiatives to combat development of herbicide resistance.
Davis, R. C. 1992. Agrichemical industry initiatives to combat development of herbicide resistance. Proceedings of the 1st International Weed Control Congress. 2: 144-147.
Lessons to be drawn from a herbicide trial programme in regards to annual ryegrass (Lolium rigidum) resistance.
Swain, J. M., W. Roy, G. S. Gill, and P. J. O' Connell. 1992. Lessons to be drawn from a herbicide trial programme in regards to annual ryegrass (Lolium rigidum) resistance. Proceedings of the 1st International Weed Control Congress. 2: 503-510.
Effect of diclofop on the membrane potentials of herbicide-resistant and -susceptible annual ryegrass root tips.
Shimabukuro, R. H. and B. L. Hoffer. 1992. Effect of diclofop on the membrane potentials of herbicide-resistant and -susceptible annual ryegrass root tips. Plant Physiology. 98: 1415-1422.
Population dynamics of herbicide resistant annual ryegrass, Lolium rigidum, in pasture.
Davidson, R. M. 1992. Population dynamics of herbicide resistant annual ryegrass, Lolium rigidum, in pasture. Proceedings of the 1st International Weed Control Congress. 2: 141-143.
Selection with sethoxydim can give resistance to cyclohexanedione and aryloxyphenoxypropionate herbicides in annual ryegrass.
Tardif, F. J., J. A. M. Holtum, S. B. Powles, and R. Knight. 1992. Selection with sethoxydim can give resistance to cyclohexanedione and aryloxyphenoxypropionate herbicides in annual ryegrass. Proceedings of the 1st International Weed Control Congress. 2: 513-515.
Metabolism of diclofop-methyl in susceptible and resistant biotypes of Lolium rigidum.
Shimabukuro, R. H. and B. L. Hoffer. 1991. Metabolism of diclofop-methyl in susceptible and resistant biotypes of Lolium rigidum. Pesticide Biochemistry and Physiology. 39: 251-260.
Amitrole, triazine, substituted urea, and metribuzin resistance in a biotype of rigid ryegrass (Lolium rigidum).
Burnet, M. W. M., O. B. Hildebrand, J. A. M. Holtum, and S. B. Powles. 1991. Amitrole, triazine, substituted urea, and metribuzin resistance in a biotype of rigid ryegrass (Lolium rigidum). Weed Science. 39: 317-323.
Annual ryegrass: an abundance of resistance, a plethora of mechanisms.
Holtum, J. A. M. and S. B. Powles. 1991. Annual ryegrass: an abundance of resistance, a plethora of mechanisms. Proceedings of the Brighton Crop Protection Conference, Weeds. 3: 1071-1078.
Cross-resistance to herbicides in annual ryegrass (Lolium rigidum). III. On the mechanism of resistance to diclofop-methyl.
Holtum, J. A. M., J. M. Matthews, R. E. Hausler, D. R. Liljegren, and S. B. Powles. 1991. Cross-resistance to herbicides in annual ryegrass (Lolium rigidum). III. On the mechanism of resistance to diclofop-methyl. Plant Physiology. 97: 1026-1034.
Cross-resistance to herbicides in annual ryegrass (Lolium rigidum) II. Chlorsulfuron resistance involves a wheat-like detoxification system.
Christopher, J. T., S. B. Powles, D. R. Liljegren, and J. A. M. Holtum. 1991. Cross-resistance to herbicides in annual ryegrass (Lolium rigidum) II. Chlorsulfuron resistance involves a wheat-like detoxification system. Plant Physiology. 95: 1036-1043.
Cross-resistance to herbicides in annual ryegrass (Lolium rigidum). IV. Correlation between membrane effects and resistance to graminicides.
Hausler, R. E., J. A. M. Holtum, and S. B. Powles. 1991. Cross-resistance to herbicides in annual ryegrass (Lolium rigidum). IV. Correlation between membrane effects and resistance to graminicides. Plant Physiology. 97: 1035-1043.
Variation in herbicide cross-resistance among populations of annual ryegrass (Lolium rigidum) resistant to diclofop-methyl.
Heap, I. M. and R. Knight. 1990. Variation in herbicide cross-resistance among populations of annual ryegrass (Lolium rigidum) resistant to diclofop-methyl. Australian Journal of Agricultural Research. 41: 121-128.
Evaluation of the petri dish assay for screening diclofop-methyl resistance in partially resistant populations of annual ryegrass, Lolium rigidum.
Gill, G. S. 1990. Evaluation of the petri dish assay for screening diclofop-methyl resistance in partially resistant populations of annual ryegrass, Lolium rigidum. Proceedings of the 9th Australian Weeds Conference. : 220-223.
On the mechanism of resistance to aryloxyphenoxy propionate and cyclohexanedione graminicides in annual ryegrass (Lolium rigidum).
Holtum, J. A. M., J. M. Matthews, D. R. Liljegren, R. E. Hausler, and S. B. Powles. 1990. On the mechanism of resistance to aryloxyphenoxy propionate and cyclohexanedione graminicides in annual ryegrass (Lolium rigidum). Proceedings of the 9th Australian Weeds Conference. : 224-228.
Effect of herbicides on the membrane potential of coleoptile cells from susceptible and cross-resistant biotypes of annual ryegrass (Lolium rigidum).
Hausler, R. E., J. A. M. Holtum, and S. B. Powles. 1990. Effect of herbicides on the membrane potential of coleoptile cells from susceptible and cross-resistant biotypes of annual ryegrass (Lolium rigidum). Proceedings of the 9th Australian Weeds Conference. : 251-254.
Control of annual grasses in pastures of southern Australia and implications for agriculture.
Leys, A. R. 1990. Control of annual grasses in pastures of southern Australia and implications for agriculture. Proceeding of the 9th Australian Weeds Conference. : 354-364.
Cross-resistance to herbicides in annual ryegrass (Lolium rigidum) . I. Properties of the herbicide target enzymes acetyl-coenzyme A carboxylase and acetolactate synthase.
Matthews, J. M., J. A. M. Holtum, D. R. Liljegren, B. Furness, and S. B. Powles. 1990. Cross-resistance to herbicides in annual ryegrass (Lolium rigidum) . I. Properties of the herbicide target enzymes acetyl-coenzyme A carboxylase and acetolactate synthase. Plant Physiology. 94: 1180-1186.
An economic response model of herbicide application for weed control.
Pannell, D. J. 1990. An economic response model of herbicide application for weed control. Australian Journal of Agricultural Economics. 34: 223-241.
Strategies to combat herbicide resistance with particular reference to annual ryegrass, Lolium rigidum, in south-eastern Australia.
Sykes, J. A., A. R. Leys, and R. M. Davidson. 1990. Strategies to combat herbicide resistance with particular reference to annual ryegrass, Lolium rigidum, in south-eastern Australia. Proceedings of the 9th Australian Weeds Conference. : 234-238.
Management of herbicide resistant annual ryegrass, Lolium rigidum, in crops and pastures.
Davidson, R. M. 1990. Management of herbicide resistant annual ryegrass, Lolium rigidum, in crops and pastures. Proceedings of the 9th Australian Weeds Conference. : 230-233.
Herbicide-resistant weeds in Australia.
Powles, S. B. and P. D. Howat. 1990. Herbicide-resistant weeds in Australia. Weed Technology. 4: 178-185.
Management of herbicides to avoid delay and control resistant weeds: a concept whose time has come.
LeBaron, H. M. 1989. Management of herbicides to avoid delay and control resistant weeds: a concept whose time has come. Proceedings of the Western Society of Weed Science. 42: 6-16.
Weeds resistant to herbicides in Australia and contributing factors leading to their appearance.
Howat, P. D. 1987. Weeds resistant to herbicides in Australia and contributing factors leading to their appearance. Plant Protection Quarterly. 2: 82-85.
The occurrence of herbicide cross-resistance in a population of annual ryegrass, Lolium rigidum, resistant to diclofop-methyl.
Heap, I. and R. Knight. 1986. The occurrence of herbicide cross-resistance in a population of annual ryegrass, Lolium rigidum, resistant to diclofop-methyl. Australian Journal of Agricultural Research. 37: 149-156.
Triazine-resistant grass weeds and their response to herbicides.
Yaacoby, T., M. Schonfeld, and B. Rubin. 1985. Triazine-resistant grass weeds and their response to herbicides. Phytoparasitica. 13: 232.
A population of ryegrass tolerant to the herbicide diclofop-methyl.
Heap, J. and R. Knight. 1982. A population of ryegrass tolerant to the herbicide diclofop-methyl. Journal of the Australian Institute of Agricultural Science. 48: 156-157.

CONTRIBUTING WEED SCIENTISTS

JIM DELLOW	Edit
Orange Agricultural Institute Forest Road Orange, 2800, NSW Australia Email Jim Dellow

JIM PRATLEY	Edit
Dean, Faculty of Science & Agriculture Charles Sturt University School of Agriculture P.O. Box 588 Wagga Wagga, 2678, N.S.W. Australia Email Jim Pratley

ANDREW STORRIE	Edit
Technical Specialist Weeds NSW Department of Primary Industries Tamworth Agricultural Institute 4 Marsden Park Road Calala, 2340, New South Wales Australia Email Andrew Storrie Web : Web Site Link

Acknowledgements

Where to now?

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

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