Globe fringerush (Fimbristylis miliacea) cross resistance to als-inhibitor herbicides under field conditions in irrigated rice in the south of Brazil

Abstract

ALS-inhibiting herbicides usually provide adequate weed control in irrigated rice fields. After consecutive years of use, the Cyperaceae species, globe fringerush (Fimbristylis miliacea) began to show resistance to ALS (acetolactate synthase) inhibitors. Globe fringerush is one of the most problematic herbicide-resistant weeds in irrigated rice in the state of Santa Catarina in the South of Brazil. The objective of this research was to examine cross resistance of globe fringerush to ALS inhibitors, under field conditions. Two experiments were conducted in a rice field naturally infested with ALS-resistant globe fringerush in Santa Catarina, in the 2008/09 and 2009/10 cropping seasons. The experimental units were arranged in randomized complete block design, with five replicates, consisting of two factors (herbicide and dose) in a 4 x 5 factorial arrangement. ALS herbicides included bispyribac-sodium, ethoxysulfuron, pyrazosulfuron-ethyl and penoxsulam. Six-leaf globe fringerush was sprayed with herbicide doses of 0, 0.5, 1, 2 and 4X the recommended doses in a spray volume of 200 L ha-1. The number of rice culm, filled and sterile grains, plant height, dry shoot biomass and grain yield were recorded. Globe fringerush control was evaluated 28 and 70 days after herbicide application (DAA); shoots were harvested at 13 weeks after herbicide application and dry weight recorded. Competition with globe fringerush reduced the number of culm and rice grain yield. The globe fringerush biotype in this field was resistant to all ALS herbicides tested. Penoxsulam had the highest level of activity among treatments at 28 and 70 DAA, but the control level was only 50% and 42%, respectively, in the second year of assessment. This was not enough to prevent rice yield loss. Alternative herbicides and weed control strategies are necessary to avoid yield losses in rice fields infested with ALS-resistant biotypes of globe fringerush.

Physical Properties and Crop Management for Corn in an Albaqualf

“…and sedges (Cyperus spp.) (Galon et al, 2008;Roso et al, 2010;Matzenbacher et al, 2013;Schaedler et al, 2013).…”

Control of globe fringerush ( Fimbristylis miliacea ) and selectivity to rice crop irrigated with bispyribac-sodium + metsulfuron-methyl associated with adjuvants

“…Recently, studies developed in southern Brazil identified F. miliacea as a species with cross-resistance to the ALS-inhibiting herbicides bispyribac-sodium, ethoxysulfuron, pyrazosulfuron-ethyl, penoxsulam, imazethapyr, imazapic, and imazapyr (Sosbai, 2012;Schaedler et al, 2013). In this sense, unlike this information, the results obtained in the present study with the in-tank mixture of bispyribac-sodium + metsulfuronmethyl, both ALS-inhibiting herbicides, did not characterize resistance behavior for this species in the studied population, and no information on the association of these herbicides was found in the literature, for comparison purposes.…”

“…Ortiz et al (2012), in a dose-response study, identified ten pyrazosulfuron-ethyl resistant populations of F. miliaceae collected in irrigated rice fields in the state of Guárico, Venezuela. In Brazil, Schaedler et al (2013) also reported the occurrence of F. miliaceae, in the state of Santa Catarina, infesting irrigated rice crop, presenting cross-resistance to the herbicides pyrazosulfuron-ethyl, penoxsulam, bispyribac-sodium, and ethoxysulfuron, being all of them acetolactate synthase (ALS) enzyme inhibitors.…”

Cross-Resistance of Rice Flatsedge to Als-Inhibiting Herbicides

“…Several cases of cross-resistance to ALS inhibitors have been reported in cyperaceae occurring in irrigated rice, such as Cyperus difformis (Galon et al, 2008), Fimbristylis miliacea (Schaedler et al, 2013), Schoenoplectus juncoides (Sada et al 2013) and, more recently, Cyperus iria (Riar et al, 2015). It is important to determine the cross-resistance spectrum, since this information may collaborate with technicians/farmers in order to select alternative herbicides for an effective weed management (Deng et al, 2014).…”