Resistance to glyphosate in Conyza spp. biotypes in western and southwestern Parana, Brazil

Planta Daninha

Xavier, E¹  Vidal, R.A¹  Coopavel Cooperativa Agroindustrial Ltda¹  EMBRAPA Soja, Londrina¹  Balbinot JR, A.A¹  Prates, M.A¹  Universidade Federal do Rio Grande do Sul, Porto Alegre¹  Trezzi, M.M¹  UTFPR¹  Universidade Tecnológica Federal do Paraná, Pato Branco¹  Rosin, D¹ 

关键词: weed resistance;    resistance factor;    genetic variability.;   

DOI  :  10.1590/S0100-83582011000500019

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

Glyphosate-resistant biotypes of Conyza spp. (hairy fleabane, horseweed) in crop areas in the western and southwestern regions of the state of Paraná, Brazil, cause great management, economic, and environmental problems. This experiment aimed to determine the existence of horseweed biotypes resistant to glyphosate in the suspected populations collected from farms in western and southwestern Parana, comparing them with susceptible biotypes. The experimental design was completely randomized in a factorial 12 x 8 x 3. The factors consisted of twelve biotypes of horseweed, eight glyphosate doses (0, 100, 180, 324, 583, 1.050, 1.888, and 3.345 g ha-1) and three evaluation periods for the control (7, 14 and 21 days after application). For the fresh and dry matter variables, the factorial design used was 12 x 8. The variables evaluated were visual inspection, fresh and dry matter, C50, GR50 and resistance factor. The dose of 3.345 g glyphosate ha-1 presented the highest control levels of all biotypes, but the control of the suspected biotypes was not effective, requiring higher doses. All the horseweed biotypes suspected of resistancetoglyphosatehaveconfirmedthisfeature.However,awiderangeofresistancefactorswas verified, characterizing the variability among the resistant biotypes. This information may be used for planning management strategies of resistant populations, as well as in preventing the occurrence of new areas infested with glyphosate-resistant horseweed.

【 授权许可】

Unknown