Search

Made available in DSpace on 2020-12-12T01:21:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Crop protection on major crops is now required to follow the principles of integrated pest management so the timing and accuracy of any application of a pesticide or biopesticide has to be more precise to minimize adverse effects on non-target species. The development of UAVs (unmanned aerial vehicles) provides a means of providing a more targeted application of the correct dose, especially by using formulations that are more persistent, thus minimizing loss of spray in areas subject to rain. Avoiding use of too high a dosage allows greater survival of natural enemies and reduces the selection pressure for pests becoming resistant to specific modes of action. The downward flow of air from a UAV should also provide better distribution and impaction of droplets within a crop canopy, reduce soil impaction caused by taking heavy loads of spray applied with 200 l ha–1 of water, and allow treatments when fields are too wet to access with ground equipment. In Asia, many smallholder farmers are using a drone in preference to using a knapsack sprayer. According to Matthews, it has been shown that ULV spraying can be effective, but it needs a narrow droplet spectrum with the droplets remaining stable and not shrinking to become too small. Formulation research can reduce the volatility of the spray, hence the success of oil-based sprays. However, instead of petroleum-based oils, there is a chance to develop vegetable oil carriers with micro-sized particle suspensions to deliver low toxicity pesticides in droplets that can be deposited within the crop and not drift beyond the crop boundary. Oil deposits will be less prone to loss after rain so less should be lost in neighbouring ditches and water courses, especially as rainfall patterns are forecast to change. More studies are needed to evaluate the swath for deposition, buffer zones, formulation, nozzle selection, to guide future specific legislation for UAV applications. AgroEfetiva Sao Paulo State University UNESP Sao Paulo State University UNESP

Made available in DSpace on 2018-12-11T16:45:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-01-01. Added 1 bitstream(s) on 2019-10-09T18:29:03Z : No. of bitstreams: 1 S0100-69162016000601118.pdf: 357183 bytes, checksum: c57d37f1771ce0fc47fb485ee70a0603 (MD5) The effect of blade angle on droplet size spectrum of five rotary cage atomizers and one rotary disc atomizer used in Brazil was evaluated in a high speed wind tunnel, with an air speed of 180 km h-1. This study included the characterization of the droplet size spectrum, via laser diffraction instrument, generated by three blades angles, of 45, 60 and 75 degrees. The spray solution was composed of Picoxystrobin + Cyproconazole fungicide (SC), at 20 mL c.p. L-1, and at a flow rate of 6 L min-1. As the angle decreased from 75 to 45 degrees, the rotational speed of the atomizers increased and the volume median diameter (VMD) decreased. However, increasing the rotational speed also increased the percentage of droplets smaller than 100 μm (% < 100 μm). At the blade angles of 45 and 60 degrees the atomizers showed that %

Made available in DSpace on 2018-12-11T17:33:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) 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−1 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 μm and relative span, while increasing the DV0.1 and DV0.5 values than the dispersion-type formulations, represented by WG and SC formulations. These factors should be considered for planning spray applications and reducing drift. Sao Paulo State University UNESP, 1780, Dr. Jose Barbosa de Barros Street University of Nebraska-Lincoln, 402, West State Farm Road Sao Paulo State University UNESP, Prof. Dr. Antônio Celso Wagner Zanin Street Sao Paulo State University UNESP, 1780, Dr. Jose Barbosa de Barros Street Sao Paulo State University UNESP, Prof. Dr. Antônio Celso Wagner Zanin Street CNPq: 99999.003632/2015-06

This paper aimed at investigating the knowledge level of people working on pesticide spraying activities concerning spray adjuvant properties, as well as collecting information on disposal locations for residues from internal spray tank cleaning, and finally the understanding of pesticide spray drift occurrence in the state of Mato Grosso, Brazil. The information was gathered through a questionnaire answered by participants of a rural extension program in application technology located in nineteen grain and fiber producing regions of Mato Grosso state. Among the mentioned adjuvants, 49.0% belonged to the mineral oil class and 17.9% of participants did not know the functions performed by such products. In addition, 58.5% of the participants discarded residues into the field. Among the participants who answered the question about spray drift occurrence causes, 54.1% indicated problems relating to inadequate weather conditions. In conclusion, there is a lack of knowledge on adjuvant functions, besides of inappropriate residue disposal in the state of Mato Grosso. Spray drift was referred as a problem; however, most of participants were not able to discuss the causes of these losses. RESUMO O objetivo deste trabalho foi investigar o nível de conhecimento de trabalhadores ligados à atividade de aplicação de defensivos agrícolas sobre as funções de adjuvantes de calda e coletar informações sobre os locais de descarte dos resíduos provenientes da lavagem interna do reservatório de calda de pulverizadores, ocorrência e motivos da deriva, nas aplicações de defensivos agrícolas, no Estado do Mato Grosso. As informações foram coletadas por meio das respostas de um questionário entregue aos participantes de um programa de extensão rural, em tecnologia de aplicação, em dezenove municípios produtores de grãos e fibras do Estado. Ao todo, 49,0% dos adjuvantes citados pertenciam à classe dos óleos minerais e 17,9% dos participantes declararam não saber as funções desempenhadas pelos adjuvantes. Os resíduos eram descartados nas lavouras por 58,5% dos participantes. Dentre os participantes que responderam sobre as causas da ocorrência de deriva nas aplicações, 54,1% indicaram problemas relativos às condições climáticas inadequadas. Conclui-se que há carência de conhecimento sobre as funções desempenhas pelos adjuvantes, bem como a ocorrência de descarte de resíduos em locais inadequados no Estado do Mato Grosso. A deriva foi reconhecida como um problema, mas a maioria dos participantes não se propôs a discutir as causas deste tipo de perda.

Muitas são as variáveis que interferem no espectro das gotas formadas em uma pulverização agrícola, a padronização do tamanho de gotas inteferem de forma significativa no resultado final de uma aplicação. O objetivo do trabalho foi analisar o comprimento dos filmes líquidos obtidos no momento da saída da calda na ponta de pulverização de jato plano XR 11002 e sua influência no tamanho das gotas produzidas. Os tratamentos foram constituídos de misturas contendo fungicidas e adjuvantes, as quais foram pulverizadas em uma pressão de 300 kPa. O diâmetro mediano volumétrico (DMV) foi determinado em analisador de gotas por difração de laser e os comprimentos dos filmes líquidos gerados nos jatos de pulverização foram determinados por videografia e análise digital das imagens. A correlação entre os dados de DMV e o comprimento do filme líquido foi analisada através do coeficiente de correlação de Pearson. Os resultados mostraram coeficientes de correlação significativos entre o comprimento do filme líquido e o DMV na pulverização formada pela pontas XR 11002. A substituição de óleos por adjuvantes não oleosos resultou em redução do DMV gerado na aplicação de fungicidas.PALAVRAS-CHAVE: espectro de gotas, pontas de pulverização, defensivos agrícolas. ANALYSIS OF THE SIZE OF LIQUID SHEET FORMED IN FLAT FAN NOZZLES AND ITS INFLUENCE ON THE VOLUME MEDIAN DIAMETERABSTRACT: There are many variables that interfere with the spectrum of droplets formed in an agricultural spray, the droplet size has a significantly interferes with the final result of an application. The objective of this work was to analyze the length of the liquid films obtained at the moment the solution exit the XR 11002 flat jet spray tip and its influence on the size of the droplets produced. The treatments were composed of mixtures containing fungicides and adjuvants, which were sprayed at a pressure of 300 kPa. The volumetric median diameter (DMV) was determined in a laser diffraction drop analyzer and the lengths of the liquid films generated in the spray nozzles were determined by videography and digital analysis of the images. The correlation between the DMV data and the liquid film length was analyzed using the Pearson correlation coefficient. The results showed significant interference with the correlation coefficients between the liquid film length and the DMV in the spray formed by the XR 11002 nozzles. The substitution of oils with non-oily adjuvants resulted in reduction of the DMV generated in the application of fungicides.KEYWORDS: Droplet spectra, nozzles, pesticides.