Document Type: Original Article

Authors

NSW Department of Primary Industries, Wagga Wagga, NSW 2650, Australia

Abstract

The rapid emergence of herbicide-resistant weeds has further added complexity to the management of weeds in Australian cotton farming systems. Fleabane (Conyza bonariensis L) has been identified by the cotton industry as being potentially resistant or at risk of developing resistance. Thirty-seven C. bonariensis populations were collected in the 2014-2015 cotton season from 9 cotton farming regions in Queensland and New South Wales. Glasshouse screening trials showed that 27 populations (73%) expressed resistance to glyphosate salt at rate of 0.68 kg a.i ha-1 applied at the rosette stage. Another 9 populations (24%) were categorised as developing resistance. A dose response study of 4 selected resistant populations using glyphosate rate of 0, 0.34, 0.68, 1.36, 2.72, and 5.44 Kg a.i ha-1 showed a high level of Resistance Index (RI) ranging from 3.5 to 7.0 and the dose-response model revealed that 3 to 4 times more glyphosate is required to control resistant C. bonariensis populations. These results further confirm the frequent reports of reduced efficacy of glyphosate against fleabane in northern cotton farming systems of Australia. To reduce the risk of resistance other non-glyphosate tactics are needed in the weed management toolbox.

Keywords

Broster J.C, Koetz E.A, Wu. H. 2011. Herbicide resistance levels in annual ryegrass (Lolium rigidum) in southern New South Wales. Plant Prot Quart.26(1): 22-27.

Cotton Australia. (2017. Cotton Australia is the key representative body for the Australian cotton growing industry; http://cottonaustralia.com.au. (Accessed 10 May 2018).

Culpepper A.S. 2006. Glyphosate-induced weed shifts. Weed Tech.20(2): 277-281.

Dinelli G, Marottii I, Bonettia A, Catizone P, Urbano JM, Barnes J. 2008. Physiological and molecular bases of glyphosate resistance in Conyza bonariensis biotypes from Spain. Weed Res. 48: 257–265.

Dogan M.N, Jabran K, Unay A. 2014.  Integrated weed management in cotton. In: Chauhan BS,  Mahajan G, editors. Recent advances in weed management. Springer Inter Pub: Cham,           Switzerland. P. 197-222.

Givens W.A, Shaw D.R, Kruger G.R, Johnson W.G, Weller S.C, Young B.G et al. 2009. Survey of tillage trends following the adoption of glyphosate-resistant crops. Weed Tech. 23:150-155.

Goh S.S, Vila-Aiub M.M, Busi R, Powles S.B. 2015. Gylphosate resistance in Echinochola colona: phenotypic characterisation and quantification of selection intensity. Pest Manag Sci.72: 67-73.

Jasieniuk M, Brûlé-Babel A.L, Morrison I.N. 1996. The evolution and genetics of herbicide resistance in weeds. Weed Sci. 44:176–193.

Knezevic S.Z, Sikemma P.H, Tardif F,  Hamill A.S, Chandler  K, Swanton C.J. 1998. Biologically effective dose and selectivity of RPA 201772 for pre-emergence weed control in corn (Zea mays). Weed Tech. 12: 670-676.

Llewellyn R.S, Powles, S.B. 2001. High levels of herbicide resistance in rigid ryegrass (Lolium rigidum) in the wheat belt of Western Australia. Weed Tech.15: 242-8.

Manalil S, Werth J, Jackson R, Chauhan B.S, Preston C. 2017.  An assessment of weed flora 14 years after the introduction of glyphosate-tolerant cotton in Australia. Crop  Pasture Sci. 68: 773–    780.

Maxwell B.D, Mortimer A. 1994. Selection for herbicide resistance. In Powles SB, Holtum JAM, editors. Herbicide resistance in plants: biology and biochemistry. Lewis Publishers. P. 1-25

Michael P.W.  1977. Some weedy species of Amaranthus (amaranths) and Conyza/ Erigeron (fleabanes) naturalized in the Asian-Pacific region. Proc 6th Asian-Pacific Weed Science    Society Conf. 87-95.

Morgan G.D, Baumann P.A, Chandler J.M. 2001. Competitive impact of palmer amaranth (Amaranthus palmeri) on cotton (Gossypium hirsutum) development and yield. Weed Tech. 15(3): 408-412.

Oerke E.C.2006. Crop losses to pests. J  Agri Sci. 44: 31-43.

Preston C, Boutsalis P, Brunton D, Kleemann S, Gill G.2018.  Herbicide resistance-where we are, where we are going and what can we do about it. Grain research update. p. 257-262.

Powles S.B, Yu Q. 2010. Evolution in action: plants resistant to herbicides. Annual Rev Plant Biol.61: 317-347.

Ritz C, Baty F, Streibig J C, Gerhard D. 2015. Dose-response analysis using R. PlosOne,.10(12): 14-21.

Seefeldt S.S, Jensen J.E, Fuerst E.P. 1995. Log-logistic analysis of herbicide dose-response relationships. Weed Tech.9(2): 218-227.

Steckel L.E, Gwathmey C.O. 2009. Glyphosate-resistant horseweed (Conyza canadensis) growth, seed production, and interference in cotton. Weed Sci. 57: 346-350.

Travlos I.S, Chachalis D. 2010.  Glyphosate-resistant hairy fleabane (Conyza bonariensis) is reported in Greece. Weed Tech. 24: 569-573.

Urbano J.M, Bborreg A, Torres V, Leon J.M, Jimenez C, Dinelli G, Barnes J. 2007. Glyphosate resistant hairy fleabane (Conyza bonariensis) in Spain. Weed Tech.21(2):396-401.

Vila-Aiub M.M, Neve P, Steadman KJ, Powles S. B. 2005. Ecological fitness of a multiple herbicide-resistant Lolium rigidum population: dynamics of seed germination and seedling emergence       of resistant and susceptible phenotypes. J Applied Ecol. 42(2):288–298.

Walker S, Bell K, Robinson G, Widderick M. 2011.  Flaxleaf fleabane (Conyza bonariensis) populations have developed glyphosate resistance in north-east Australian cropping fields. Crop Prot30: 311-317.

Walker S.R, Robinson G.R. 2008. Flaxleaf fleabane e the next glyphosate resistant weed? Pro 6th Australian Weeds Conf. p. 88-90.

Wicks G.A, Felton W.L, Murison R.D, Martin R.J. 2000. Changes in fallow weed species in continuous wheat in northern New South Wales. Australian J  Exp Agri. 40: 831-842.

Wilson D.G, York A.C, Jordan D.L. 2007. Effect of row spacing on weed management in glufosinate-resistant cotton. Weed Tech.21: 489-495.

Wu H. 2007. The biology of Australian weeds. Conyza bonariensis (L) Cronquist. Plant Prot  Quart. 22: 122-131.

Young B.G. 2006. Changes in herbicide use patterns and production practices resulting from glyphosate-resistant crops. Weed Tech. 20(2):301-307.