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| Cunha,João Paulo Arantes Rodrigues da; Nascimento,Ana Paula de Castro. |
| Pesticides can be applied by aircraft, ground-sprayers or sprinkler irrigation. However, selecting the best option is complicated by the limited number of studies comparing these techniques. Thus, the objective of this work was to study the chlorpyrifos insecticide deposition applied by aircraft (30 L ha-1), tractor-mounted sprayer (200 L ha-1) and chemigation (70,000 L ha-1) for the control of Spodoptera frugiperda (J.E. Smith) in two corn (Zea mays L.) populations (70,000 and 100,000 plants ha-1). Active ingredient residue on the corn plant leaves was evaluated by gas chromatography, immediately and ten days after the treatments. Armyworm numbers in each plot and control were also evaluated. The experiment was set up in randomized blocks with four... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Insecticide application technology; Fall armyworm; Chemigation; Sprayer. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542013000200002 |
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| Bomfim,Guilherme V. do; Manzano,Juan; Azevedo,Benito M. de; Vasconcelos,Denise V.; Viana,Thales V. de A.. |
| The purpose of this research was to evaluate the K2O distribution uniformity by surface drip irrigation at Universitat Politecnica de Valencia, Valencia, Spain (39º 29′ N, 0º 23′ W, 20 m). The irrigation was performed by drip lines with not-compensated emitters, spaced 0.3 m. The fertigation was realized using a fertilizer injector pump of electric action with injection of 0.25 h. The experimental design used completely randomized blocks with five treatments and four replications. The treatments consisted of injection in five distances, located at 10; 20; 30; 40; 50 m of the first drip line. Samples were collected in emitters located at the start, at 1/3, at 2/3 and at the end of the drip lines. The nutrient concentration was determined by flame... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Uniformity; Chemigation; K2O. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000600011 |
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| Manzano,Juan; Palau,Carmen V.; Benito,M. de Azevedo; Guilherme,V. do Bomfim; Vasconcelos,Denise V.. |
| ABSTRACT To determine the influence of geometry on the hydrodynamic behavior of Venturi injectors, using computational fluid dynamics techniques, we studied, at the Universitat Politècnica de València, Valencia, Spain, the geometric parameters that exert the most influence on head losses: the relationship between throat diameter and nozzle (β), nozzle angle (α1) and diffuser angle (α2). In addition, three throat morphologies (B1: nozzle-throat and throat-diffuser with a sharp edge; B2: nozzle-diffuser with a zero-length, sharp-edge throat; B3: nozzle-throat and throat-diffuser with rounded edge). We analyzed their influence on the velocity distribution and differential pressure between inlet and throat (DP/γ), throat and outlet (Δhv/γ), and outlet and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemigation; Fertirrigation; DFC. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000300482 |
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| Souza,Renan S. de; Rezende,Roberto; Freitas,Paulo S. L. de; Gonçalves,Antonio C. A.; Rezende,Graziela S.. |
| ABSTRACT The objective of this study was to evaluate, in greenhouse, the response of the lettuce cultivar 'Vera', with respect to the marketable shoot dry matter production and macronutrient accumulation, as a function of the application of different doses of nitrogen (N) and a potassium silicate-based leaf fertilizer. The lettuce was cultivated from August 10, 2012 (sowing) to October 16, 2012 (harvest). The experimental design was completely randomized with three replicates, referring to nine treatments, resulting from the combination between top-dressing doses of N (9, 54, 90, 126 and 171 kg ha-1) and Si/K2O (1.15, 6.90, 11.50, 16.10 and 21.85 kg ha-1), using the Plan Puebla III experimental matrix, and a control treatment without fertigation. Drip... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactuca sativa L.; Chemigation; Dry mass; Nutritional composition. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015001201166 |
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| Manzano,Juan; Palau,Carmen Virginia; Azevedo,Benito Moreira de; Bomfim,Guilherme Vieira do; Vasconcelos,Denise Vieira. |
| ABSTRACT Venturi-type chemigation injectors are widely used due to their advantages: they do not require electric power and are cheap to operate. However, they also generate considerable energy losses which affect the pressure in the system. The correct characterization of these systems requires pressures to be correctly set at the inlet, injector and outlet points in relation to main and injected solution flows. These analytical relationships, as described in the International Organization for Standardization’s standard ISO 15873:2002, can be obtained theoretically, although it is recommended that the manufacturer should determine the real behavior of the injector by operational tests. These relationships should also be provided graphically in the form of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemigation; Fertigation; Head losses; Nomography. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902018000200201 |
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