Barnyardgrass with Multiple Resistance to Synthetic Auxin, ALS and Accase Inhibitors

Abstract

-The objective of this research was to confirm the resistance of a barnyardgrass biotype (Echinochloa crus-galli) to herbicides quinclorac (synthetic auxin), penoxsulam (ALS inhibitor) and cyhalofop-butyl (ACCase inhibitor). Two experiments were carried out in a greenhouse located in Itajaí, State of Santa Catarina, Brazil. One experiment evaluating the biotype ECH 18 (known as susceptible) and one with the ECH 141 biotype (suspected to be multiple resistant). The experimental design used was completely randomized, in a 4 x 7 factorial arrangement with four replications. The first factor was the herbicide: cyhalofopbutyl (Clincher ® ), penoxsulam (Ricer ® ), quinclorac (Facet ® ) and propanil (Grassaid ® ) and the second factor consisting of seven rates of each herbicide (0.00; 0.25; 0.50; 1; 2; 4 and 8 times the label rate). The evaluations of percentage of control, plant density per pot and dry mass of shoots were performed 35 days after treatments. The rates to control 50% and 80% and the dose to provide 50% and 80% of the weed biomass accumulation and the resistance factor were estimated based on data analysis. The initial hypothesis was confirmed; the biotype ECH 141 presented multiple resistance (synthetic auxin, ALS and ACCase inhibitor). However, the herbicide propanil controlled biotype ECH 141 adequate.Keywords: Paddy rice, Echinochloa crus-galli, chemical control, herbicide resistance. (0,00, 0,25, 0,50, 1,00, 2,00, 4,00 RESUMO -Este estudo teve como objetivo confirmar a resistência múltipla de um biótipo de capimarroz (Echinochloa crus-galli) aos herbicidas auxínicos (quinclorac), inibidores da ALS (penoxsulam) e ACCase (cyhalofop-butyl). Foram conduzidos dois experimentos em casa de vegetação localizada no município de Itajaí/SC: um com o biótipo ECH 18 (sabidamente suscetível) e outro com o biótipo ECH 141 (com suspeita de resistência múltipla). O delineamento experimental utilizado foi o inteiramente casualizado (DIC), organizado em arranjo fatorial 4 x 7, com quatro repetições. O primeiro fator avaliado foram os herbicidas: cyhalofop-butyl, penoxsulam, quinclorac e propanil (Clincher ® , Ricer ® , Facet ® e Grassaid ® , respectivamente). O segundo fator consistiu de sete doses de cada herbicida

Identification of Echinochloa spp. populations resistant and susceptible to acetolactate synthase-inhibiting and auxin-mimic herbicides

“…mitis, which is still found, as shown in this study. The results of multiple resistance found in rice grass populations resistant to auxin-mimic and ALS-inhibiting herbicides may be related to gene flow among rice grass species (Mariot et al, 2010;Eberhardt et al, 2016). Dornelles et al (2010) highlight the gene flow between red rice biotypes and Clearfield ® cultivars in Rio Grande do Sul State, leading to the emergence of red rice plants resistant to herbicides belonging to the imidazolinone chemical group.…”

“…Rio Grande do Sul State has confirmed cases of rice grass biotypes resistant to auxin-mimic and ALS-inhibiting herbicides. Mariot et al (2010) and Eberhardt et al (2016) reported the occurrence of rice grass biotypes resistant to the herbicide quinclorac. Menezes & Mariot (2009) found E. crus-galli biotypes resistant to herbicides imazethapyr and imazapic, showing problems with the Clearfield ® system, which combines a rice variety resistant to imidazolinone herbicides (ALS inhibitors) with the use of these herbicides to control red rice and rice grass.…”

Management of penoxsulam- and bispyribac-resistant late watergrass ( Echinochloa phyllopogon ) biotypes and rice sedge ( Cyperus difformis ) in rice

“…China ranged from 28.2 to 80.7 g ha -1 , while some biotypes were simultaneously resistant to other rice herbicides such as bispyribac, quinclorac, cyhalofop, oxadiazon, and pretilachlor. Also, Eberhardt et al (2016) reported one barnyard grass biotype in Brazil with multiple resistance to penoxsulam, cyhalofop, and quiclorac, but susceptible to propanil. For both shoot number and fresh weight data, the ratios (R/S) of the resistant or moderately-resistant to susceptible ED50 values were greater than 5.7 and 3.6 for penoxsulam and bispyribac, respectively.…”

Aryloxyphenoxypropionate in association with others herbicides in controlling weedy rice and barnyardgrass

“…The arrival of the Clearfield ® technology in Brazil, in the early 2000s, allowed using herbicides from the imidazolinones chemical group (acetolactate synthase inhibitors -ALS) in the irrigated rice crop, thus becoming the main tool for controlling these weed species. However, the great selection pressure caused by continuously using these herbicides caused a rapid increase in the biotypes number of weedy rice (Rubim et al, 2014;Burgos et al, 2014;Dauer et al, 2018) and barnyardgrass (Eberhardt et al, 2016;Rouse et al, 2018) resistant to this herbicides group.…”