Consistent spray coverage that is evenly distributed throughout the canopy is necessary to control pest populations that can negatively affect yield. As applicators are switching to Coarser spray quality nozzles to reduce risk and liability of pesticide spray drift, concerns about efficacy loss are growing. Previous research has indicated that small droplets are the most effective at penetrating through crop canopies, but newer nozzle technologies have improved the effectiveness of larger droplet or Coarser sprays. Research was conducted to assess the canopy penetration of nozzles that produce Coarse, Very-Coarse and Extremely-Coarse spray qualities compared to nozzles that produce Fine and Medium spray qualities. Kromekote collectors were positioned in four configurations in an oat (Avena sativa L.) var. 'Yarran' (AusWest Seeds, Forbes, NSW, Australia) crop to quantify the coverage and droplet number densities (droplets cm À2) across three application carrier volume rates: 50, 75 and 100 L ha À1. Applications were made in the field in 30 cm tall, tillering oats, with collectors arranged in a randomised complete block design with three replications. The entire study was repeated on the following day. Results showed that droplet number densities were inversely related to the droplet size produced by the nozzles, yet coverage was increased more by application volume rate than droplet size. Thus, both spray drift reduction and improved canopy penetration can be achieved with proper nozzle selection and operation parameters for the control of agronomic pests.
The influence of three types of commercial formulation of insecticides and fungicides, emulsifiable concentrate (EC) formulation, suspension concentrate (SC) formulation and water dispersible granule (WG) formulation on the surface tension, viscosity and the droplet size spectra of sprays was evaluated using thirty commercial insecticide and fungicide products. The concentration of sprays was based on application water spray volume of 50 L ha À1 using an XR 8003VS flat fan nozzle, operated at 200 kPa pressure. The lowest surface tensions were obtained with EC formulations, while the SCs had the highest viscosities. Emulsions were the most effective at decreasing the percentage of droplets smaller than 100 mm and relative span, while increasing the DV 0.1 and DV 0.5 values than the dispersion-type formulations, represented by WG and SC formulations. These factors should be considered for planning spray applications and reducing drift.
The addition of a DRT oil is an effective way to reduce the spray solution drift potential across all nozzle types and tank mixes evaluated in this study. The greatest reduction in drift potential can be achieved by changing nozzle type, which can reduce the losses of the spray to the surrounding environment. Venturi nozzles greatly reduce the drift potential compared with standard nozzles by as much as 85% across all three insecticide spray solutions. Results suggest that a significant reduction in drift potential can be achieved by changing the nozzle type, and can be achieved without a loss in control of DBM. © 2016 Society of Chemical Industry.
RESUMO -O uso inadequado da tecnologia de aplicação de agrotóxicos, relacionados ao uso de pontas de pulverização e adição de adjuvantes, resulta diretamente em um maior risco de deriva. Objetivou-se como trabalho quantificar a deriva gerada por pontas de pulverização com e sem indução de ar, em aplicações de glyphosate e adjuvantes. O experimento foi realizado em túnel de vento, com o herbicida glyphosate isolado ou em mistura com ureia ou adjuvante redutor de deriva (LI700). As coletas foram realizadas, com fios de polietileno, nas distâncias de 5,0; 10,0 e 15,0 m em relação à barra e nas alturas de 0,2; 0,4; 0,6; 0,8 e 1,0 m em relação ao piso do túnel, a deriva foi aferida por meio do processo de condutividade elétrica. Os resultados apresentaram maior deriva nas menores alturas, tendo igual comportamento para todas as caldas e em todas as distâncias. A ponta de jato plano com indução de ar (AVI 110-015) proporcionou menor deriva em relação à ponta jato plano padrão (AXI 110-015), para todas as caldas avaliadas. Para a ponta de jato plano padrão o acréscimo de adjuvante reduziu a deriva para as três distâncias avaliadas em relação à calda contendo somente o herbicida. Já para a ponta de jato plano com indução de ar a ureia elevou a deriva para todas as distâncias em relação às outras caldas. A ureia pode ser utilizada em aplicações com o modelo de ponta jato plano padrão, por diminuir os riscos de deriva.Palavras-chave: Tecnologia de aplicação. Agrotóxicos. Ureia. Plantas-efeito dos herbicida. Túnel de vento. ABSTRACT -The improper use of pesticide-application technology, related to the use of spray nozzles and the addition of adjuvants, is directly related to a greater risk of drift. This study aimed to quantify the spray drift generated by nozzles, both with and without air induction, in applications of glyphosate and adjuvants. The experiment was conducted in a wind tunnel, using the herbicide, glyphosate, either pure or in combination with urea or a drift-reducing adjuvant (LI700). Collections were made on polyethylene strings, at distances of 5.0, 10.0 and 15.0 m from the spray-boom, and at heights of 0.2, 0.4, 0.6, 0.8 and 1.0 m from the floor of the tunnel; the drift was measured using a process of electrical conductivity. The results showed greater drift at the lower heights, giving the same results for all solutions and at all distances. The flat nozzle with air induction (AVI 110-015) gave a smaller drift relative to the standard flat nozzle (AXI 110-015) for all solutions tested. With the standard flat nozzle, adding an adjuvant reduced the drift at the three distances tested, for the solution containing pure herbicide. For the flat fan nozzle with air induction however, the urea increased drift at all distances compared to other the spray solutions. Urea can be employed in applications where the standard flat tip model is used, as it reduces the risk of drift.
ABSTRACT:The reduction of pesticide spraying drift is still one of the major challenges in Brazilian agriculture. The aim of this study was to evaluate the potential of different adjuvant products, such as surfactants, drift retardants, mineral oil and vegetable oil for reducing drift in agricultural spraying. The experiment consisted of quantifying drift of sprayings of 18 adjuvants dissolved in water under controlled conditions in a wind tunnel. Tests were performed in triplicates with spraying nozzles type Teejet XR8003 VK, pressure of 200kPa and medium drops. Solutions sprayed were marked with Brilliant Blue dye at 0.6% (m v -1 ). The drift was collected using polyethylene strips transversally fixed along the tunnel at different distances from the nozzle and different heights from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry in order to quantify deposits. The adjuvants from chemical groups of mineral oil and drift retardant resulted in lower values of drift in comparison with surfactants and water. The results obtained in laboratory show that the selection of appropriate class and concentration of adjuvants can significantly decrease the risk of drift in agricultural spraying. However, the best results obtained in laboratory should be validated with pesticide under field conditions in the future. KEYWORDS:Wind tunnel, drift retardant, mineral oil, vegetable oil, surfactant. POTENCIAL DE ADJUVANTES PARA REDUÇÃO DA DERIVA EM PULVERIZAÇÕES AGRÍCOLAS RESUMO:A redução da deriva das pulverizações agrícolas continua sendo um dos maiores desafios da agricultura brasileira. O objetivo deste trabalho foi avaliar o potencial de adjuvantes dos grupos surfatantes, redutores de deriva, óleos minerais e óleos vegetais para a redução da deriva em pulverizações agrícolas. O experimento quantificou a deriva de pulverizações realizadas com 18 adjuvantes em diferentes concentrações, em solução aquosa, sob condições controladas em túnel de vento. Os ensaios foram realizados em triplicatas, com pontas de pulverização Teejet XR8003 VK, pressão de 200 kPa e gotas médias. As soluções pulverizadas foram marcadas com corante Azul Brilhante a 0,6% (m v -1 ). A deriva foi coletada por meio de fios de polietileno posicionados transversalmente ao fluxo de ar, a diferentes distâncias da ponta e alturas do piso do túnel. A solução de lavagem de cada fio foi processada por meio de espectrofotometria para a quantificação dos depósitos. Os adjuvantes dos grupos funcionais óleos minerais e redutores de deriva proporcionaram valores menores de deriva em comparação com os surfatantes e a água. Os resultados de laboratório indicam que a seleção de produtos e de concentrações adequadas pode reduzir significativamente o risco de deriva nas pulverizações agrícolas. Entretanto, os melhores resultados obtidos em laboratório deverão ser validados com os produtos que irão constituir as caldas de pulverização em condições de campo no futuro.
a b s t r a c tPrevious work sought to compare the results from imaging software for characterising droplet coverage, but none exists examining these five software programs: Droplet Scan Ò , Swath Kit Ò , Deposit Scan, Image J, and Drop Vision Ò -Ag. Additionally, a freely available smartphone application (App), SnapCard was developed to provide an extension tool for in-field analysis of spray collectors, but nothing has been published regarding its comparison to other imaging software systems. The present study was conducted to compare five existing imaging software types against the new App, SnapCard. Six nozzles producing different spray qualities were selected to spray a water + Brilliant Blue Dye solution over two artificial collector types (water sensitive paper and Kromekote Ò ). Each collector was assessed for percent coverage using the five imaging systems and SnapCard. Objectives of this study were: 1. To establish a baseline dataset using the sprayed cards and five commonly used imaging systems, and compare the coverage results from each. 2. Use the baseline data from Objective 1 as a measurement of precision to judge the results from SnapCard. 3. Make an assessment of SnapCard against the other imaging software type data in the study.Results showed that SnapCard has similar measured coverage means compared to other image analysis systems. For both collector types, SnapCard measured coverage within one standard deviation of the means across nozzle types. SnapCard is able to provide an immediate answer without expensive software or needing a laboratory to measure sprayed collector coverage with precise results, which further underscores its value. The other software types were not all similar for coverage, but the data followed the same trends for droplet size. Increasing the droplet size consistently decreased the coverage, across both collector types. Droplet Scan reported the highest coverage while Drop Vision-Ag and Swath Kit gave lower coverage values on water sensitive paper and Kromekote Ò collectors, respectively.
ResumoA deriva está diretamente ligada ao uso inadequado da tecnologia de aplicação de agrotóxicos, sendo a correta seleção das pontas de pulverização e adjuvantes importantes variáveis para auxiliar em sua redução. O objetivo deste trabalho foi estimar o potencial de deriva em túnel de vento com diferentes pontas de pulverização e diferentes concentrações de adjuvantes. O ensaio foi composto por seis caldas (óleo vegetal (em três concentrações), óleo mineral, surfatante e redutor de deriva), aplicadas com pontas de pulverização anti-deriva, jato plano com pré-orifício (DG 8003 VS) e indução de ar (AI 8003 VS). O equipamento utilizado foi um túnel de vento, onde as coletas de deriva foram realizadas em diferentes pontos. As médias dos tratamentos foram comparadas pelo Intervalo de Confiança, a 95% de probabilidade. A análise da porcentagem de deriva demonstrou que os tratamentos tiveram comportamentos distintos. O adjuvante nonil fenol etoxilado apresentou a maior deriva quando aplicado com a ponta de pré-orifício e a menor deriva quando aplicado com a indução de ar. Porém, comportamento contrário foi observado quando o adjuvante a base de óleo foi utilizado para as mesmas pontas. Para a ponta DG o menor percentual de deriva em todas as distâncias analisadas foi para o tratamento óleo vegetal (1,0%) e para a ponta AI a menor deriva foi encontrada no tratamento com o adjuvante nonil fenol etoxilado (0,0625%) nas quatro distâncias de coleta. Pode-se concluir que as pontas de pulverização e os adjuvantes testados alteram diretamente o potencial de deriva. Não houve proporcionalidade entre as concentrações do adjuvante a base de óleo vegetal testadas com a porcentagem de deriva. Palavras-chave: Tecnologia de aplicação, surfatante, óleo vegetal, óleo mineral AbstractThe drift is intimately linked to inappropriate use of pesticides and an important factor for reducing it, is the correct selection of spray nozzles and adjuvants. The objective of this work was to evaluate the drift potential in wind tunnel with different spray nozzles and different concentrations of adjuvants. The experiment was composed by six spray solutions (vegetable oil (in three concentrations), mineral
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