Charged Pesticide Spray Swath and Volumetric Droplets Distribution Impact by Nozzle Types, Spacing and Height:

Samuel Appah; Christopher   A. Ayambire; Eric  Amoah Asante

Samuel Appah University for Development Studies https://orcid.org/0000-0003-3226-9269
Christopher A. Ayambire University for Development Studies
Eric Amoah Asante Kwame Nkrumah University of Science and Technology https://orcid.org/0000-0001-8078-0702

Keywords: Pesticide spray, charged spray swath, volumetric droplets, nozzle types, uniformity index

Abstract

Understanding charged pesticide spray swath and volumetric droplets distribution in a spray continuum is an innovative strategy to reduce spray overlap and improve spraying efficiency. Pesticides spray overlap and accumulation on substrates from single or multiple nozzle(s) do not only waste chemicals but also increase lethal dosage. The parameters to enhance uniformity of in-situ droplet deposition at reduced surface overdose are required for efficient pesticide application. A factorial experiment arranged in a Completely Randomised Design comprising flat-fan (FF) and hollow-cone (HC) nozzle types, 2, 3, 4 bar flow pressures, 50, 75, 100 and 120 cm nozzle spacings (S) and 40, 50, 60 cm spraying heights (H) at three replicates were investigated to determine charged spray swath (Wn) and volumetric (Qn ) droplets distribution from a developed inductive nozzle cap mounted on a telescopic boom. The FF-nozzle produced relatively smaller charged droplet sizes, DV0.5 (67.4-79.2μm), wider spray swath Wn (R2 = 98.37 %; max. 185 cm) and higher Qn distribution (C37 collectors, 15.86 mls-1), than HC-nozzle of DV0.5 (70-92.5 μm), narrow spray swath Wn (R2 = 85.45 %; max. 115 cm) and lower Qn distribution (C23 collectors, 15.72 mls-1) respectively. A spray Uniformity Index (UI) allowed permissible spraying of FF-nozzles at 0.4 and HC-nozzles at 0.3-0.42, but spraying above 0.33 increased overlap and application rate, and below 0.08 decreased spraying efficiency. Hitherto, spraying from FF-nozzles at 0.12-0.18 yielded uniformity of Qn distribution, while HC-nozzles were effective at 0.25, corresponding to 25-50 % spray overlap. Therefore, to reduce pesticide spray overlap on substrates, FF-nozzles should be mounted at 50 cm H × 100 cm S or HC-nozzles at 60 cm H × 75 cm S on the boom under 4 bar flow pressure, as the electrostatic spraying system provides timely and effective pesticide application in crop protection.

Author Biographies

Christopher A. Ayambire, University for Development Studies

Christopher Amigangre Ayambire is an Assistant Lecturer in the Department of Agricultural Mechanization and Irrigation. He specialized in Agricultural Mechanization and did research on prediction of soil forces and soil strength during tillage operations and determined the output level of draft animals. He has provided instructions for students in Principles of land survey, Agricultural Mechanization and Irrigation, Agricultural machinery, Agricultural power unit and students thesis in the undergraduate level. His research interests is on evaluating the performance, designing and fabrication of Agricultural machinery, determining the work output of the various power sources of Agriculture. He is also interested in the forces that react with implement part that have direct contact with soils during tillage operations.

Eric Amoah Asante, Kwame Nkrumah University of Science and Technology

Dr. Eric Amoah Asante has been a Lecturer at the Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana since August, 2020. He is currently with the Agricultural Machinery Engineering section of the department. He holds a PhD in Agricultural Engineering, and his areas of research include design of agricultural machinery; Soil tillage; and Welding and fabrication. He has expertise in the use of scanners such as Terahertz Spectroscopy and Hyperspectral Imaging for the detection of physiological properties of plants; CAD simulations for agricultural machinery design optimization.

Charged Pesticide Spray Swath and Volumetric Droplets Distribution Impact by Nozzle Types, Spacing and Height

Pesticide Spray Distribution and Nozzle Effects

Abstract

Author Biographies