Selectivity of Chlorimuron-Ethyl to Castorbean Crops.

Castorbean presents high sensitivity to competition; therefore, it is necessary to develop alternatives for the weed management, mainly for the chemical control of eudicotyledons species. The goal of this work was to evaluate the selectivity of chlorimuron-ethyl to castorbean crops in different development stages. Four experiments differentiated by the genetic material were conducted: Lyra, Íris and Savana hybrids and AL Guarany 2002 cultivar. The treatments corresponded to the application conditions of chlorimuron-ethyl [sample control with no application, doses of 15 e 20 g a.i. ha-1 with the formulations Classic? and Clorimuron Master Nortox?] in two phenological crop stages (4 to 5 and 7 to 8 true leaf stages). The experimental design was in randomized blocks with four replications, in a factorial scheme of 5 x 2 (herbicide and application stage). The intoxication was more severe for the 7 to 8 leaf stage and with the dose of 20 g ha-1 on day 7 days after application (DAA); there were plant recovery and mild symptoms on day 21 DAA, especially for the 4 to 5 leaf stage. The yield was reduced with the 20 g ha-1 dose for Lyra hybrid with both formulations and for Savana castorbean, only with the Classic? formulation. The chlorimuron-ethyl herbicide, at 15 g ha-1, showed selectivity to castorbean, regardless of the stage application (4 to 5 or 7 to 8 leaves).Made available in DSpace on 2017-12-23T23:18:35Z (GMT). No. of bitstreams: 1 Selectivityof....pdf: 3172976 bytes, checksum: f205c85d0dae95bf20f0435f9b468a4b (MD5) Previous issue date: 2017-12-21bitstream/item/169616/1/Selectivity-of-....pdfPublicação online

Selectivity of Iodosulfuron-Methyl Association with ACCase Inhibitors and 2.4-D in Wheat and Barley Crops

<div><p>ABSTRACT: This research aimed to assess the selectivity of treatments involving the commercial formulations tank mixtures of iodosulfuron-methyl with herbicides ACCase inhibitors (fenoxaprop-p-ethyl and clethodim) and synthetic auxins (2.4-D), applied in post-emergence of wheat (Triticum aestivum) and barley (Hordeum vulgare) crops. Three experiments were conducted in the field, during the 2014 crop year. A randomized complete block design was used with 11 treatments and five replications. Treatments consisted of (g ha-1): 1) iodosulfuron-methyl (6.5), 2) fenoxaprop-p-ethyl (82.5), 3) fenoxaprop-p-ethyl + clethodim (55 + 54); 4) 2.4-D (335), 5, 6 e 7) iodosulfuron-methyl + fenoxaprop-p-ethyl (6.5 + 82.5; 6.5 + 110 and 6.5 + 165), 8) iodosulfuron-methyl + fenoxaprop + clethodim (6.5 + 55 + 54), 9) iodosulfuron + fenoxaprop-p-ethyl + 2.4-D (6.5 + 110 + 335), 10) iodosulfuron-methyl + fenoxaprop-p-ethyl + clethodim + 2.4-D (6.5 + 82.5 + 72 + 335) and 11) check without weeds. Associations of iodosulfuron-methyl + fenoxaprop-p-ethyl (6.5 + 82.5; 6.5 + 110 and 6.5 + 165 g ha-1) associations, as well as of iodosulfuron-methyl + fenoxaprop-p-ethyl + 2.4-D (6.5 + 110 + 335 g ha-1) were selective for BRS Campeiro and BRS Gralha azul wheat cultivars and did not feature symptoms of intoxication and significant losses in grain yield and hectoliter weight, when compared to the treatment with no application. For BRS Brau barley cultivar, only iodosulfuron-methyl + fenoxaprop-p-ethyl associations, in doses of 6.5 + 82.5 and 6.5 + 110 g ha-1 were feasible for selectivity. Clethodim addition in iodosulfuron-methyl + fenoxaprop-p-ethyl or iodosulfuron-methyl + fenoxaprop-p-ethyl + 2.4-D associations caused negative effects for wheat and barley crops. Commercial formulation of iodosulfuron-methyl (Hussar™) resulted in protection for damage effects of fenoxaprop-p-ethyl (Podium EW™) for studied crops.</p></div

Selectivity of Chlorimuron-Ethyl to Castorbean Crops

<div><p>ABSTRACT: Castorbean presents high sensitivity to competition; therefore, it is necessary to develop alternatives for the weed management, mainly for the chemical control of eudicotyledons species. The goal of this work was to evaluate the selectivity of chlorimuron-ethyl to castorbean crops in different development stages. Four experiments differentiated by the genetic material were conducted: Lyra, Íris and Savana hybrids and AL Guarany 2002 cultivar. The treatments corresponded to the application conditions of chlorimuron-ethyl [sample control with no application, doses of 15 e 20 g a.i. ha-1 with the formulations Classic™ and Clorimuron Master Nortox™] in two phenological crop stages (4 to 5 and 7 to 8 true leaf stages). The experimental design was in randomized blocks with four replications, in a factorial scheme of 5 x 2 (herbicide and application stage). The intoxication was more severe for the 7 to 8 leaf stage and with the dose of 20 g ha-1 on day 7 days after application (DAA); there were plant recovery and mild symptoms on day 21 DAA, especially for the 4 to 5 leaf stage. The yield was reduced with the 20 g ha-1 dose for Lyra hybrid with both formulations and for Savana castorbean, only with the Classic™ formulation. The chlorimuron-ethyl herbicide, at 15 g ha-1, showed selectivity to castorbean, regardless of the stage application (4 to 5 or 7 to 8 leaves).</p></div