Droplet spectrum of a spray nozzle under different weather conditions

Christiam Felipe Silva Maciel, Mauri Martins Teixeira, Haroldo Carlos Fernandes, Sérgio Zolnier, Paulo Roberto Cecon

Resumo


The application of pesticides is always susceptible to losses through evaporation and drift of the spray droplets. With these losses, a smaller amount of pesticide reaches the target, possibly impairing the efficiency of phytosanitary control. Due to these concerns, the aim of this study was to evaluate the interference of weather conditions in the droplet spectrum produced by hydraulic spraying. To carry out the work, it was necessary to build an experimental system. This consisted of a laser particle-size analyser, hydraulic nozzle (Jacto JSF 11002), stationary sprayer, gas heater, wind tunnel, climate chamber (with the aim of maintaining the internal psychrometry similar to that of the air exiting the wind tunnel), collector, and temperature and RH sensors. The weather conditions for the study included vapour pressure deficits (VPD) of 5, 9.4, 20, 30.6 and 35 hPa, and air velocities of 2, 3.6, 7.4, 11.2 and 12.8 km h-1. A Rotatable Central Composite Design was used, and the data related using Response Surface Methodology. The wind caused such a sharp drift in the fine droplets, that it greatly affected the behaviour of the entire droplet spectrum, as well as hiding the effect of the VPD. However, the conclusion is that drift and evaporation both act on the coarser droplets.

Palavras-chave


Spraying losses; Droplet drift; Droplet evaporation; Hydraulic spraying; Laser particle-size analyser

Texto completo:

PDF

Referências


AIR MOVING AND CONDITIONING ASSOCIATION. Laboratory methods of testing fans for rating. Arlington Heights: AMCA 210- 99, 2000. 69 p.

ALVARENGA, C. B. et al. Déficit de pressão de vapor d’água no ar na distribuição de líquido utilizando um pulverizador hidropneumático. Amazonian Journal of Agricultural and Environmental Sciences, v. 56, n. 2, p. 81-87, 2013.

ALVARENGA, C. B. et al. Efeito do déficit de pressão de vapor d’água no ar na pulverização hidropneumática em alvos artificiais. Bioscience Journal, v. 30, n. 1, p. 182-193, 2014.

ALVARENGA, C. B.; CUNHA, J. P. A. R. Aspectos qualitativos da avaliação de pulverizadores hidráulicos de barra na região de Uberlândia, Minas Gerais. Engenharia Agrícola, v. 30, n. 3, p. 555-562, 2010.

AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS. Spray nozzle classification by droplet spectra. St. Joseph: ASAE S572.1, 2009. 4 p.

ARVIDSSON, T.; BERGSTRÖM, L.; KREUGER, J. Spray drift as influenced by weather and technical factors. Pest Management Science, v. 67, p. 586-598, 2011.

BALAN, M. G. et al. Deposição da calda pulverizada por três pontas de pulverização sob diferentes condições meteorológicas. Semina: Ciências Agrárias, v. 29, n. 2, p. 293-298, 2008.

CARLSEN, S. C. K.; SPLIID, N. H.; SVENSMARK, B. Drift of 10 herbicides after tractor spray application. 2. Primary drift (droplet drift). Chemosphere, v. 64, p. 778-786, 2006.

CHAIM, A. et al. Método para monitorar perdas na aplicação de agrotóxicos na cultura de tomate. Pesquisa Agropecuária Brasileira, v. 34, n. 5, p. 741-747, 1999.

GIL, E. et al. Determination of drift potential of different flat fan nozzles on a boom sprayer using a test bench. Crop Protection, v. 56, p. 58-68, 2014.

HOLTERMAN, H. J. Kinetics and evaporation of water drops in air. Wageninger: IMAG, 2003. 67 p.

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION. Equipment for crop protection: spraying equipment. Part 1: Test methods for sprayer nozzles. Geneva: ISO 5682-1, 1996. 5 p.

MACIEL, C. F. S. et al. Droplets spectrum at different vapour pressure deficits. Revista Ciência Agronômica, v. 47, n. 1, p 41-46, 2016.

MATTHEWS, G. A. Pesticide application methods. 3rd edition. London: Blackwell Science, 2000. 448 p.

NASCIMENTO, A. B. et al. Deposição de glifosato e utilização de adjuvante para diferentes pontas de pulverização e horário de aplicação. Pesquisa Aplicada & Agrotecnologia, v. 5, n. 2, p. 105-110, 2012.

NUYTTENS, D. et al. Experimental study of factors influencing the risk of drift from field sprayers. Part 1: Weather conditions. Aspects of Applied Biology, v. 77, p. 1-8, 2006.

NUYTTENS, D. et al. Comparison between indirect and direct spray drift assessment methods. Biosystems Engineering, v. 105, p. 2-12, 2010.

SASAKI, R. S. et al. Uniformidade de distribuição volumétrica de pontas de pulverização hidráulica em diferentes condições operacionais. Engenharia na Agricultura, v. 19, n. 6, p. 541-547, 2011.

SASAKI, R. S. et al. Spectrum of droplets produced by use of adjuvants. Idesia, v. 31, n. 1, p. 27-33, 2013.

SASAKI, R. S. Droplets spectrum of air-assisted boom sprayers under different environmental and operational conditions. Agriambi, v. 20, n. 1, p. 92-96, 2016.

TOBI, I. et al. Determination of accuracy level of agricultural spraying application in Sanliurfa/Turkey. African Journal of Agricultural Research, v. 6, n. 28, p. 6064-6072, 2011.




Revista Ciência Agronômica ISSN 1806-6690 (online) 0045-6888 (impresso), Site: www.ccarevista.ufc.br, e-mail: ccarev@ufc.br - Fone: (85) 3366.9702 - Expediente: 2ª a 6ª feira - de 7 às 17h.