Alteração Das Propriedades Físico-Químicas Na Aplicação Contendo Adjuvantes

Abstract

RESUMOEste trabalho teve como objetivo avaliar as alterações produzidas por doze adjuvantes em algumas propriedades físico-químicas das caldas de aplicação, sobre a área de molhamento de folhas de soja e sobre a alteração no tamanho de gotas. As avaliações foram realizadas sob condições ambientais controladas em laboratório. Foram utilizadas duas pontas de modelo leque na avaliação da variação do tamanho das gotas: jato plano SF; e com pré-câmara TT. A análise da variação do espalhamento da gota sobre a superfície foliar foi realizada utilizando-se o programa ImageJ. A tensão superficial e a viscosidade das caldas foram mensuradas por metodologias laboratoriais simples como a mensuração da massa de gotas e pelo método de Stokes, respectivamente. Todos os adjuvantes apresentaram redução da tensão superficial da calda. O adjuvante siliconado Break-Thru proporcionou redução na tensão superficial de 3,6 vezes em comparação à água destilada e também apresentou o maior espalhamento da calda sobre a superfície foliar em 13,5 vezes. Entretanto, também apresentou a maior taxa de evaporação da gota. Exceto o adjuvante Break-Tru, todos os adjuvantes apresentaram evaporação semelhante estatisticamente ao controle até aos 30 minutos após a aplicação. O adjuvante Gota Max proporcionou o maior aumento da viscosidade da calda e o adjuvante Hygrogem a maior redução da viscosidade em comparação à água. O uso de adjuvante diminui o tamanho de gota e aumenta o percentual de gotas maiores que 100 µm quando a ponta é do tipo SF de uso padrão. Quando do uso da ponta TT, a adição de adjuvante à calda não impactou em variação do tamanho das gotas ou na variação do índice SPAN, mas aumentou o percentual de gotas menores que 100 µm pelo uso do adjuvante Break-Thru. O uso do adjuvante Gota Max proporcionou maior amplitude relativa quando utilizando a ponta SF.Palavras-chave: gotas, deriva, tecnologia de aplicação. CHANGING THE PHYSICAL AND CHEMICAL PROPERTIES IN THE APPLICATION CONTAINING ADJUVANTS ABSTRACTThis work aimed to evaluate the changes produced by twelve adjuvants in some physicochemical properties of the pesticides application, over the wetting area of soybean leaves and the change in droplet size. The evaluations were conducted under controlled environmental conditions in the laboratory. Two flat fan nozzle models were used to evaluate the variation of the droplet size: SF standard fan nozzle; and TT pre-chamber. The variation analysis of the drop spreading over the leaf surface was performed using ImageJ software. The surface tension and viscosity of the mixtures were measured by simple laboratory * fabiobaio@ufms.br Journal of Biosystems Engineering v. 9(2): 151-161, 2015 152 methods such as the drop mass measurement and Stokes method, respectively. All adjuvants reduced the surface tension of the spray mixture. The adjuvant Break-Thru silicone based gave a reduction in surface tension of 3.6 times compared to distilled water and also showed the highest solution spreading over the leaf surface by 13.5 times. However, it al...

Adjuvants in Fungicide Spraying in Wheat and Soybean Crops

“…The figures confirm the statements of AGUIAR JÚNIOR et al (2011), BUENO et al (2013), CUNHA et al (2010, SILVA-MATTE et al (2014) and XU et al (2010). They are contrary to the findings of BAIO et al (2015), however, which highlighted significant differences in surface tension of adjuvants Aureo (Bayer © ) and TA35 (Inquima © ); with lower values for Aureo at the same dose, and similar to TA35 adjuvant , at a ten times higher dose. The incidence and severity of foliar diseases in wheat were affected by fungicide application.…”

“…When evaluating aqueous solutions with adjuvants for agricultural use at 25 °C, CUNHA et al (2010) concluded that the same adjuvant kept the spray stable, altered its pH, and reduced water surface tension from 71 to 33 mN m -1 . When checking the water physicochemical properties with and without adjuvants, BAIO et al (2015) emphasize that water surface tension was reduced The aim of this study was to verify if the association of adjuvant to fungicide significantly alters the spray physicochemical characteristics and potentiates the chemical control of foliar diseases to the extent that it may affect yield components in wheat and soybean crops.…”

Interactions Between Adjuvants and the Fungicide Azoxystrobin+benzovindiflupyr in Hydraulic Spraying

“…Cunha et al (2017) evaluated the physicochemical properties of spray mixtures and found that there was a strong interaction effect between adjuvants and pesticides, supporting the results in this study. Baio et al (2015) and Sasaki et al (2015) observed that adjuvants affected surface tension and spray viscosity, respectively. Surface tension ranged from 20.03 to 72.60 mN m -1 and solution viscosity decreased up to 0.04%, which corroborates the present study.…”

“…The fungicide mixture alone increased the reduction in droplet diameter from 4.38% to 9.04%. Several studies have already evaluated the evaporation time of droplets on surfaces (Baio et al, 2015;Xu et al, 2010;Yu et al, 2009). This may help understand the evaporation process after droplets reach the target area since surface contact changes droplet shape and evaporation time (Erbil, 2015;Santiago, 2016).…”

Estimation of sulfentrazone sorption in isolated application and mixed with glyphosate

“…The presence of surfactants and adjuvants in the formulated product Roundup Ultra ® may cause changes in the physicochemical characteristics of the water present in the soil solution, such as electrical conductivity, surface tension and pH (DA CUNHA;ALVES, 2009;BAIO et al 2015). The reduction of pH may favour the sorption of sulfentrazone in the soil, since it has a weak acid behaviour.…”