PREFERÊNCIA DE EQÜINOS EM PASTEJO: EFEITO DA ALTURA DE DOSSÉIS DE GRAMÍNEAS DO GÊNERO CYNODON

The experiment was conducted at the experimental farm of the Federal University of Paraná, in February, 1998, and investigated the effect of the different Cynodon grasses structure at the horse grazing. The Cynodon spp. cv Tifton 85, Cynodon nlemfuensis cv Tifton 68, Cynodon spp. cv Tifton 44, Cynodon nlemfuensis (¨Porto Rico¨) and Cynodon nlemfuensis (¨Estrela Roxa¨) grasses were distributed in parcels with 12 m2 in a completely randomized split-plot design with four replications. The parcels were divided in two kinds of patches (tall and short) demonstrated by plants height. Five grazing tests were done with mares, evaluating the number of bites allocated in each treatment. The preference was evaluated by bite number and tiller grazed on each treatment. The bite depth was measured using 20 marked tillers in each experimental unit. The animals showed preference for Tifton 85, followed by Coastcross 1, Tifton 68 and Tifton 44. The star grasses ¨Estrela Roxa¨ and ¨Porto Rico¨ were not preferred. Tifton 85 and Coastcross 1 with more leaves and less stems mass (PO experimento foi conduzido no Centro de Estações Experimentais da Universidade Federal do Paraná, em fevereiro de 1998, quando as gramíneas Cynodon spp. cv Tifton 85, Cynodon nlemfuensis cv Tifton 68, Cynodon spp. cv Tifton 44, Cynodon nlemfuensis (Porto Rico) e Cynodon nlemfuensis (Estrela Roxa) foram estabelecidas em parcelas em um delineamento inteiramente casualizado com parcelas subdivididas e quatro repetições. As parcelas foram subdivididas em duas alturas do dossel (alto e baixo) caracterizadas pela diferença de altura das plantas. Os tratamentos foram ofertados a três éguas por duas horas em cinco dias consecutivos. A preferência entre os tratamentos foi identificada pela avaliação do número de bocados e pela desfolha nas unidades vegetativas marcadas nas parcelas e alturas. A profundidade do bocado foi quantificada por meio da identificação da altura do perfilho estendido e da menor altura pastejada nos perfilhos marcados das diferentes gramíneas. A Tifton 85 foi preferida, seguida pela Coastcross 1, Tifton 68 e Tifton 44. A Estrela Roxa e a Porto Rico foram preteridas. As gramíneas de maior preferência apresentavam maior massa de folhas verdes em relação à massa de colmos (

Desempenho e características das carcaças de novilhos superprecoces em pastos hibernais submetidos a intensidades de pastejo

O objetivo deste trabalho foi avaliar os efeitos de intensidades de pastejo na terminação de novilhos superprecoces, em pastagens de inverno em sucessão à soja. Foram avaliadas diferentes alturas de pré-pastejo de pastos mistos de azevém e aveia: 10, 20, 30 e 40 cm. Empregou-se o delineamento de blocos ao acaso, com três repetições. Foram utilizados machos mestiços de raças de corte, inteiros, com idade de 10 meses e peso médio inicial de 192±12 kg. As seguintes variáveis foram avaliadas: massa e oferta de forragem, altura do pasto, taxa de acúmulo diário e acúmulo total de forragem, ganho de peso médio diário (GMD), carga animal e ganho de peso vivo por unidade de área (GPA), além de características qualitativas de carcaça. Os novilhos foram abatidos aos 14 meses de idade. O GMD ajustou-se a um modelo de regressão quadrático e teve o ponto de máximo desempenho entre 20 e 25 cm de altura de pré-pastejo, enquanto o GPA ajustou-se a um modelo linear negativo. A qualidade da carcaça dos novilhos foi satisfatória, quando os pastos foram manejados em alturas superiores a 10 cm. É possível produzir carcaças de novilhos superprecoces, na fase de pastagem de sistemas integrados de produção, durante o inverno, em sucessão à soja. O manejo de pastos mistos de azevém e aveia, em alturas entre 20 e 25 cm, otimiza o desempenho animal individual e por área

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

Rendimento de milho em área de integração lavoura-pecuária sob o sistema plantio direto, em presença e ausência de trevo branco, pastejo e nitrogênio Corn yield on no tillage crop-pasture rotation in presence and absence of white clover, grazing and nitrogen

O trabalho experimental foi realizado no campo, na Estação Experimental da Fundação Agrária de Pesquisa Agropecuária (FAPA), em Guarapuava (PR), Brasil, nos anos agrícolas de 1999 e 2000, com o objetivo de verificar a influência da adubação nitrogenada residual na cultura do milho, em Sistema Plantio Direto, cultivado em seqüência, em áreas que no inverno tinham presença e ausência de trevo branco e de animais em pastejo. O delineamento experimental foi o de blocos ao acaso com três repetições. Os tratamentos foram arranjados em parcelas subdivididas. No inverno, nas parcelas, foram aplicados quatro doses de nitrogênio (N-TI = 0, 100, 200 e 300 kg ha-1 de N) e, nas subparcelas, a combinação de presença e ausência de trevo branco e de pastejo (CT = com trevo; ST = sem trevo; CP = com pastejo e SP = sem pastejo). No verão, em cada subparcela proveniente do inverno, foram aplicadas cinco doses de N (N-TV = 0, 60, 120, 180 e 240 kg ha-1 de N), em cobertura, e cultivado o milho. A máxima eficiência técnica de rebrote da cultura de inverno, avaliada dezoito dias após a retirada dos animais, foi obtida com a aplicação de 231 kg ha-1 de N (N-TI). As áreas CP/N-TI apresentaram maiores produtividades do milho que as áreas SP; contudo, estes resultados não foram estatisticamente significativos. As áreas sem N-TI produziram mais milho em subparcelas SP. As parcelas que receberam 300 kg ha-1 de N N-TI não mostraram resposta do milho ao N-TV, comprovando o efeito residual do N-TI. Conclui-se que a interação entre pastejo e N-TI contribui para a nutrição nitrogenada da cultura do milho.<br>This field experiment was carried out at the Fundação Agrária de Pesquisa Agropecuária [Agrarian Foundation for Agricultural and Cattle Research] (FAPA), in Guarapuava, State of Paraná, Brazil, during the growing seasons of 1999 and 2000. The objective was to verify residual effects of nitrogen fertilization on maize crop under a no tillage system, in presence and absence of white clover and grazing animals. The experimental layout was a completely randomized block design with three replications. The treatments were arranged in split-plots. Four N rates (N-TI = 0, 100, 200, and 300 kg ha-1 of N) were previously applied on the main plots during the winter season, while the treatments of the sub-plots consisted in combinations of presence and absence of white clover and grazing (CT = with clover; ST = without clover; CP = with grazing, and SP = without grazing). During the summer each sub-plot that had been prepared during the winter was cultivated with corn which received five N rates (N-TV = 0, 60, 120, 180, and 240 kg ha-1 of N) top dressed. The maximum re-growth efficiency of winter culture plants occurred eighteen days after the animals had been removed from the plots, obtained with 231 kg ha-1 of N (N-TI). The areas CP/N-TI presented higher corn yields than the SP plots, although these differences were not statistically significant. The areas without N-TI produced most in the SP subplots. On plots that had received 300 kg ha-1 of N N-TI there was no response of corn to the N-TV, confirming the residual effect of N-TI. The conclusion was drawn that the interaction between grazing and N-TI contributes to nitrogen nutrition in maize