Assessment of premixing in-line injection system attached on variable-rate orchard sprayer

Authors: ZHANG, ZHIHONG - Kunming University Of Science And Technology; Zhu, Heping; SALCEDO, RAMON - The Ohio State University; WEI, ZHIMING - Shandong Academy Of Agricultural Sciences

Submitted to: Journal of ASTM International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2020
Publication Date: 9/10/2020
Citation: Zhang, Z., Zhu, H., Salcedo, R., Wei, Z. 2020. Assessment of premixing in-line injection system attached on variable-rate orchard sprayer. Journal of ASTM International, Pesticide Formulation and Delivery Systems. 4:11-24. https://doi.org/10.1520/stp162720190120.
DOI: https://doi.org/10.1520/stp162720190120

Interpretive Summary: New agrochemical application technologies must deliver pesticides precisely and maintain spray mixtures uniformly without tank mixture leftovers. To achieve this goal, a premixing in-line injection system was developed and attached to the advanced intelligent sprayers. The injection system stored water and chemical concentrates in separate tanks and mix them in the fluid line before the spray nozzles. With this design, chemical concentrate leftovers could be saved for future use. In this research, field tests were conducted in a nursery field to investigate if the premixing in-line injection system was able to dispense chemical concentrates and water accurately, and mix them with desired concentrations and adequate uniformity. There were no significant differences between measured and calculated concentrations of spray mixtures before delivered to spray nozzles, thereby offering a potentially new pesticide reduction technology for future nursery, orchard, and vineyard applications.

Technical Abstract: An intelligent variable-rate sprayer, retrofitted with premixing in-line injection system, for orchard spraying, was tested to evaluate its performance in the field. Operation parameters included desired chemical concentrations and duty cycle combinations. To evaluate dispensing accuracy and discharging accuracy of metering pump and water pump separately, a flow rate testing platform was built with two IO-Link standardized magnetic-inductive flow meters. To assess the chemical concentration accuracy and mixing uniformity, fluorescent tracer technique was used to analyze the spray mixtures discharged from this system. It was confirmed that based on the nominal concentration input, chemical concentrates could be accurately dispensed with the metering pump, and water as chemical carrier could be accurately charged with the water pump, separately. The field test results showed that the premixing in-line injection system was able to provide acceptable chemical concentration accuracy and desirable mixing uniformity for variable flow-rate spray nozzles. The premixing in-line injection system has great potentials for variable-rate precision sprayers to further reduce chemical waste and environmental pollution.