Characterization of biological pesticide deliveries through hydraulic nozzles

Authors: XIAO, LIPING - Jiangxi Agricultural University; Zhu, Heping; Wallhead, Matthew; Horst, Leona; LING, PETER - The Ohio State University; Krause, Charles

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2018
Publication Date: 7/1/2018
Citation: Xiao, L., Zhu, H., Wallhead, M.W., Horst, L., Ling, P., Krause, C.R. 2018. Characterization of biological pesticide deliveries through hydraulic nozzles. Transactions of the ASABE. 61(3):897-908. https://doi.org/10.13031/trans.12698.
DOI: https://doi.org/10.13031/trans.12698

Interpretive Summary: Biopesticides, many of which are considered as natural and safer pest control agents, are in great demand to control or inhibit agricultural pests and diseases. They are not persistent, and thus, reduce the risks for accumulation in the environment. However, delivery of the numerous biopesticides is one of the most challenges in their applications and requires different application systems to achieve efficacy and efficiency. In this research, the question was addressed on whether hydraulic nozzles could deliver adequate spray quality on targets for newly released biopesticides. Investigations included evaluation of droplet size distribution, spray pattern width, viscosity, surface tension, and spray deposition quantity of six different classes of biopesticides discharged from five types of flat-fan nozzles with three flow capacities. Test results demonstrated that droplet sizes and spray pattern widths varied significantly with the biopesticide class, nozzle type, and nozzle flow capacity. Biological control evaluations were recommend to verify the effectiveness of these biological pesticides discharged through flat-fan pattern nozzles to control specific insects and diseases under field conditions. Consequently, a scientific basis was generated from this research for choosing nozzles and operating parameters that could efficiently and effectively deliver biopesticides with controlled spray application characteristics.

Technical Abstract: Increased use of biopesticides have spurred demand for efficient and effective delivery systems. To this goal, laboratory tests were conducted to investigate six different classes of biopesticides discharged from six different types of flat-fan pattern nozzles with three flow capacities. The biopesticide classes were horticultural oil insecticide (HOI), wettable powder mineral-salt bio-fungicide (MSBF), liquid fungal bio-insecticide (FBI-ES), wettable powder fungal bio-insecticide (FBI-WP), liquid suspension bacterial bio-fungicide (BBF), and liquid botanical extract bio-insecticide (BEBI). Droplet size distributions, spray pattern widths, spray deposition and coverage on plant leaves and water sensitive papers (WSP) were spray parameters tested. Outcomes of these parameters varied greatly with biopesticide classes, nozzle types and nozzle flow capacities. DV0.5 of these biopesticides ranged from 75 to 519 µm for 0.76 L min-1 flow capacity nozzles, from 86 to 509 µm for 1.51 L min-1 nozzles, and from 99 to 622 µm from 2.25 L min-1 nozzles. The use of different biopesticides with the same nozzle significantly altered spray pattern widths. Compared to water-only solution, the largest spray pattern width change was 14.7% from the air induction nozzle AI11004 discharging the FBI-ES bio-insecticide. Amounts of spray deposits of all tested biopesticides (except for the HOI) on plant leaves, on the other hand, did not vary significantly with different types of nozzles. The air induction nozzle, however, produced the most uneven spray deposition patterns. Therefore, to achieve optimal spray application efficiency and effectiveness for discharging specific classes of biopesticide, the choice of a proper nozzle type and flow capacity is critical.