Roberto Busi1, Stephen B Powles. 1. Australian Herbicide Resistance Initiative, School of Plant Biology and Institute of Agriculture, University of Western Australia, Crawley, Western, Australia.
Abstract
BACKGROUND: Plants can rapidly evolve resistance to herbicide in response to repeated selection. This study focuses on cross-resistance patterns observed in Lolium rigidum following pyroxasulfone recurrent selection. RESULTS: The parental MR (multiresistant) population following four generations of pyroxasulfone recurrent selection evolved cross-resistance to prosulfocarb and triallate. At the recommended label rate of prosulfocarb or triallate (2000 g ha(-1) ), the progeny selected four times with pyroxasulfone (MR4) displayed 58 and 35% plant survival respectively. One additional cycle of prosulfocarb selection increased the resistance level to both prosulfocarb and triallate in the population MR4-P1. Prosulfocarb resistance is yet to be reported in L. rigidum field populations. CONCLUSIONS: This study suggests that L. rigidum plants can rapidly evolve cross-resistance to several wheat-selective herbicides under recurrent selection of a single mode of action. Weed populations displaying broad-spectrum cross-resistance to several herbicide modes of action are increasing in frequency in intensive world agriculture. Proactive and integrated measures for resistance management need to be developed globally on appropriate herbicide use in crop rotations.
BACKGROUND: Plants can rapidly evolve resistance to herbicide in response to repeated selection. This study focuses on cross-resistance patterns observed in Lolium rigidum following pyroxasulfone recurrent selection. RESULTS: The parental MR (multiresistant) population following four generations of pyroxasulfone recurrent selection evolved cross-resistance to prosulfocarb and triallate. At the recommended label rate of prosulfocarb or triallate (2000 g ha(-1) ), the progeny selected four times with pyroxasulfone (MR4) displayed 58 and 35% plant survival respectively. One additional cycle of prosulfocarb selection increased the resistance level to both prosulfocarb and triallate in the population MR4-P1. Prosulfocarb resistance is yet to be reported in L. rigidum field populations. CONCLUSIONS: This study suggests that L. rigidum plants can rapidly evolve cross-resistance to several wheat-selective herbicides under recurrent selection of a single mode of action. Weed populations displaying broad-spectrum cross-resistance to several herbicide modes of action are increasing in frequency in intensive world agriculture. Proactive and integrated measures for resistance management need to be developed globally on appropriate herbicide use in crop rotations.
Authors: José G Vázquez-García; Ricardo Alcántara-de la Cruz; Candelario Palma-Bautista; Antonia M Rojano-Delgado; Hugo E Cruz-Hipólito; Joel Torra; Francisco Barro; Rafael De Prado Journal: Front Plant Sci Date: 2020-10-28 Impact factor: 5.753