Effects of nozzle size, travel speed and air assistance on deposition on artificial vertical and horizontal targets in laboratory experiments

Nordbo, Ebbe

doi:10.1016/0261-2194(92)90049-b

Cited by 26 publications

(18 citation statements)

References 6 publications

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“…Nordbo et al (1995), who found no increased benefit with bifluid nozzles, reported that conventional hydraulic nozzles provided similar spray deposition on white mustard (Sinapis alba L.) and greater deposition on oat (Avena sativa L.), compared with bifluid nozzles, and herbicidal weed control in sugar beet (Beta vulgaris L.) was similar with both nozzles. In laboratory trials, spray deposition on simulated plants was increased with air assistance compared with no air assistance over spray qualities varying from very fine to coarse (Nordbo 1992). Potato (Solanum tuberosum L.) leaf coverage with a fungicide was greater with air-assisted nozzles compared with flat-fan nozzles (0.18% vs. 2.15% coverage), but performance of the fungicide for control of late blight [Phytophthora infestans (Mont.)…”

Section: Discussionmentioning

confidence: 98%

Evaluation of foliar fungicide application methods on soybean

Bradley

Chesrown

Hofman

2007

Canadian Journal of Plant Pathology

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A field trial was conducted at Fargo, North Dakota, in 2005 and 2006 to evaluate different fungicide application methods on soybean (Glycine max). Kromekote ® paper cards were placed in the upper and lower canopy of soybean plants, and tebuconazole fungicide mixed with a blue dye was sprayed with different application methods at the R5 developmental stage. The applications were made with a conventional sprayer with Turbo TeeJet ® 110015 flatfan nozzles at 276 kPa liquid pressure, a conventional sprayer with XR TeeJet ® 80015 flat-fan nozzles at 276 kPa liquid pressure, an AirJet ® bifluid nozzle spray system with liquid pressure at 276 kPa and air pressure at both 76 and 48 kPa, or an air-assisted spray system with liquid pressure at both 221 and 83 kPa. An untreated control was also included to evaluate the effect of tebuconazole on soybean yield. Dye-sensitive Kromekote paper cards were analyzed to determine the percent coverage and the volume median diameter (VMD) of the droplets. Significant (P ≤ 0.05) interactions between year and application method were detected, most likely resulting from differences in plant height and development between the years. Droplet coverage in the upper canopy did not differ in either year among the application methods. Most application methods provided similar droplet coverage in the lower canopy in 2005, but the conventional sprayer with XR TeeJet 80015 flat-fan nozzles provided the greatest coverage in the lower canopy in 2006. Correlation analysis indicated that droplet coverage in the lower canopy increased with increased VMD of the droplets in 2005 (R = 0.91), and that yield increased with increased fungicide coverage in 2006 (R = 0.85). Visible symptoms of foliar fungal diseases were not present in either year, and tebuconazole had no effect on soybean yield, compared with the untreated control in either year. Bradley et al.: soybean / fungicide application / comparison of methods 202 Résumé : En 2005 et 2006, un essai au champ fut mené à Fargo, Dakota du Nord, pour évaluer différentes méthodes d'application de fongicides sur le soja (Glycine max). Des cartes de papier Kromekotez furent placées aux niveaux supérieur et inférieur du couvert végétal du soja, et du fongicide tébuconazole, mélangé à un colorant bleu, fut pulvérisé selon différentes méthodes d'application au stade de développement R5. Les applications ont été effectuées avec un pulvérisateur traditionnel équipé de buses à jet plat Turbo TeeJetz 110015 à une pression du liquide de 276 kPa, un pulvérisateur traditionnel équipé de buses à jet plat XR TeeJetz 80015 à une pression du liquide de 276 kPa, un système de pulvérisation équipé de buses AirJetz à émulsions inverties multiphases à une pression du liquide de 276 kPa et une pression d'air de 76 et 48 kPa, ou un système de pulvérisation à air assisté à une pression du liquide de 221 et 83 kPa. Un témoin non traité fut aussi inclus pour évaluer l'effet du tébuconazole sur le rendement du soja. Les cartes de papier Kromekote sensible au colorant furent analysée...

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Section: Discussionmentioning

confidence: 98%

Evaluation of foliar fungicide application methods on soybean

Bradley

Chesrown

Hofman

2007

Canadian Journal of Plant Pathology

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“…O glyphosate é mais ativo em concentrações mais altas, como tem sido verificado por vários autores (Stahlman & Phillips, 1979;Jordan, 1981;Singh & Tucker, 1983;Buhler & Burnside, 1983e 1987McWhorter & Hanks, 1993). Por outro lado, o aumento da velocidade de deslocamento melhora a cobertura de superfícies verticais (Nordbo, 1992). No controle do capimamargoso (Tabela 3), esse fenômeno parece ser visualizado, com exceção para o tratamento XR110015+OC-02, em que a velocidade de 5 km h -1 forneceu resultados numéricos superiores à velocidade de 4 km h Os resultados da avaliação efetuada aos 8 DAA do paraquat estão mostrados na Tabela 6. )…”

Section: Resultsunclassified

Uniformidade de deposição da calda de pulverização de herbicidas em barra lateral protegida com diferentes combinações de pontas de pulverização

2001

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RESUMO -O presente trabalho objetivou estudar a uniformidade de distribuição da calda de pulverização contendo herbicidas, em culturas perenes arbustivas, utilizando combinações de pontas de pulverização em barra lateral protegida, conduzida a pequena distância do alvo, na linha de culturas perenes arbustivas. Para isso, foi desenvolvido um programa computacional que permite simular a sobreposição do leque de pulverização, da porção protegida da barra e do leque formado pela ponta de pulverização do bico mais extremo da barra, de modo diferente dos demais programas. Após a seleção das melhores combinações de pontas de pulverização por meio de simulação dos padrões de deposição da pulverização das pontas individuais e dos coeficientes de variação menores que 10%, algumas dessas combinações foram testadas em campo, aplicando-se um herbicida sistêmico (glyphosate) e outro com ação de contato (paraquat). Os resultados indicaram que o programa computacional desenvolvido pode constituir-se em um auxiliar valioso para a seleção das melhores combinações de pontas de pulverização. Em aplicações tanto do herbicida glyphosate quanto do paraquat, com volumes de calda mais reduzidos,abaixo de 100 L ha -1 , destacaram-se como arranjos mais eficientes: a) pontas TT110015 distanciadas de 52,5 cm entre si, combinadas com a ponta TK-0,5 na extremidade da barra a 50 cm do último bico, operando na velocidade de 5 km h -1 e pressão de 103 kPa (15 lbf pol ), com distância de caminhamento do tronco da árvore de 30 cm ; e c) pontas TLX-2 distanciadas de 15 cm entre si, combinadas com a ponta TK-0,5 na extremidade da barra de 20 cm do último bico, operando à velocidade de 5 km h -1 e pressão de 414 kPa (60 lbf pol -2 ), com distância de caminhamento do tronco da árvore de 30 cm. A velocidade de deslocamento do pulverizador de 5 km h -1 proporcionou melhores condições para que os herbicidas estudados apresentassem melhor controle de plantas daninhas, quando comparada com a velocidade de deslocamento do pulverizador de 4 km h -1 . Palavras-chave:bico de pulverização, barra de pulverização, espaçamento de bico, simulação de pulverização, barra protegida. ABSTRACT -This

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“…On the other hand, coarse droplets generally provide good drift control. In dicotyledons, the deposits do not depend only on droplet size (Nordbo, 1992). Unlike the results with smaller diameter droplets, coarse droplets provide significantly lower deposits on vertical surfaces (monocotyledons), and especially in the first growth stages, by increasing the loss to soil proportionally to their size (Jorgensen & Witt, 1997).…”

Section: Air Assistance and Spray Driftmentioning

confidence: 98%

“…Preliminary studies have shown that the increase of the displacement speed with air-assisted sprayers may reduce drift, but provide lower evenness in the target culture treatment (Miller, 1997). However, aiming at reducing the application volume, Nordbo (1992) has demonstrated lower variation and improved deposit by using air assistance. The density, architecture, cuticle type (pilose, glabrous and waxy) and growth stage of the vegetal species in the area are factors influencing phyto-sanitary control efficiency when using air-assisted sleeve boom sprayers.…”

Section: Air Assistance and Spray Driftmentioning

confidence: 99%