Planta Daninha (Jan 2010)

Tensão superficial estática de misturas em tanque de glyphosate + chlorimuron-ethyl isoladas ou associadas com adjuvantes Static superficial tension of glyphosate and chlorimuron-ethyl tank mixtures with or without adjuvants

  • C.D.G. Maciel,
  • N. Guerra,
  • A.M. Oliveira Neto,
  • J.P. Poletine,
  • S.L.W. Bastos,
  • N.M.S. Dias

DOI
https://doi.org/10.1590/S0100-83582010000300025
Journal volume & issue
Vol. 28, no. 3
pp. 673 – 685

Abstract

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Objetivou-se neste estudo avaliar a tensão superficial estática, o pH e a produção da espuma de misturas em tanque de glyphosate + chlorimuron-ethyl, associadas ou não com adjuvantes. Dois trabalhos foram realizados, sendo a primeira etapa desenvolvida em delineamento inteiramente casualizado com seis tratamentos e 20 repetições, representados por soluções dos herbicidas glyphosate (540,0 g e.a. ha-1) e chlorimuron-ethyl (7,5 g ha-1), isolados e em mistura em tanque nas formulações: Polaris®; Roundup Ready®; Classic®; Polaris® + Classic®; Roundup Ready® + Classic® e testemunha (água). Na segunda etapa foram estudados em DIC 70 tratamentos e 20 repetições, em fatorial 2 x 5 x 7, constituído por duas misturas de glyphosate com chlorimuron-ethyl (Polaris® + Classic® e Roundup Ready ® + Classic®), cinco adjuvantes (Joint Oil®; Nimbus®; Assist®; Natur' Oil® e Agr' Óleo®) e sete doses dos adjuvantes (0,000; 0,031; 0,062; 0,125; 0,250; 0,500 e 1,000% de v/v). As soluções de Polaris® e Roundup Ready®; isoladas ou em misturas com Classic®; caracterizaram-se por tensões superficiais estáticas de 43,2 e 35,9 mN m-1 e pH médios em torno de 4,5 a 4,6, respectivamente. As misturas de Polaris®+Classic®; Roundup Ready®+Classic® e Classic® apresentaram a maior quantidade e persistência da espuma ao longo do tempo, quando comparadas às formulações de Polaris® e Roundup Ready®. Os adjuvantes promoveram redução da tensão superficial quando associados às misturas de Polaris® + Classic® e Roundup Ready® + Classic®; caracterizando-se em termos de eficiência pela ordem decrescente: Nimbus® (36,5% e 25,8%) This work aimed to evaluate static superficial tension, pH and foam production in glyphosate + chlorimuron-ethyl tank mixtures with or without adjuvants. The experiment consisted of two stages, with the first stage being arranged in a complete randomized design, with six treatments and 20 replications, represented by glyphosate (540.0 g a.e. ha-1) and chlorimuron-ethyl (7.5 g ha-1) solutions, isolated and in tank mixtures in the following formulations: PolarisTM, Roundup ReadyTM, ClassicTM, PolarisTM + ClassicTM, Roundup ReadyTM + ClassicTM and check (water). The second stage was also arranged in a complete randomized design, with 70 treatments and 20 replications, in a 2 x 5 x 7 factorial scheme constituted by two mixtures of glyphosate with chlorimuron-ethyl (PolarisTM + ClassicTM and Roundup ReadyTM + ClassicTM), 5 adjuvants (Joint OilTM, NimbusTM, AssistTM, Natur' OilTM and Agr' ÓleoTM) and 7 adjuvant doses (0.000; 0.031; 0.062; 0.125; 0.250; 0.500 and 1.000% of v/v). PolarisTM and Roundup ReadyTM solutions , isolated or in tank mixtures with ClassicTM, characterized by static superficial tensions of 43.2 and 35.9 mN m-1 and medium pHs, around 4.5 to 4.6, respectively. PolarisTM + ClassicTM, Roundup ReadyTM + ClassicTM and ClassicTM solutions showed the highest foam quantity and persistence during the time, compared to PolarisTM and Roundup ReadyTM mixtures. Adjuvants promoted reduction of static superficial tension when associated with PolarisTM + ClassicTM and Roundup ReadyTM + ClassicTM mixtures, being characterized in efficiency by this decreasing order: NimbusTM (36.5% and 25.8%) < Joint OilTM (32.2% and 25.2%) < Agr' OilTM (21.2% and 13.4%) < Natur' OilTM (17.4% and 10.6%) < AssistTM (8.5% and 10.6%). Adjuvants promoted reduction of foam quantity and persistence in the PolarisTM + ClassicTM and Roundup ReadyTM + ClassicTM mixtures, with small variations in the medium levels of pH of the solutions lower than 0.5.

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