Control effect on cotton aphids of insecticides sprayed with unmanned aerial vehicles under different flight heights and spray volumes

Abstract

Unmanned aerial vehicles (UAVs) are an emerging technology increasingly used to control plant diseases and pests in China. However, the efficacy of UAV spraying in cotton fields remains unclear. This paper assesses the droplet deposition of UAV spraying and analyzes how flight heights and spray volumes affect aphids control in cotton fields. Allura red was used as a tracer and Kromekote cards were used to collect the droplets. The research results demonstrated that droplet uniformity, droplet coverage, and droplet density were all higher at a flight height of 1.5 m and a spray volume of 22.5 L/ha. Control efficacy on the first day after spraying was correlated with the number of droplets deposited on the underside of leaves, and higher droplet coverage and density resulted in better pest control. Optimal control efficacy on the seventh day after spraying was achieved at the flight height of 1.0 m and 1.5 m, with control efficacy rates ranging from 57.93% to 80.53%. Field trials of five different insecticides verified the efficacy of UAV spraying controls against cotton aphids. These results provide a theoretical reference and technical support for subsequent UAV spraying to control for diseases and pests. Keywords: unmanned aerial vehicle, flight parameter, spray volume, droplet deposition, cotton aphids DOI: 10.33440/j.ijpaa.20210401.161 Citation: Hu H Y, Ren X L, Ma X Y, Li H H, Ma Y J, Wang D, et al. Control effect on cotton aphids of insecticides sprayed with unmanned aerial vehicles under different flight heights and spray volumes. Int J Precis Agric Aviat, 2021; 4(1): 44–51.