Efficiency of reduced volume spraying aimed to control the Leucoptera coffeella (Lepidoptera: lyonetiidae)

Abstract

The objective of the study was to evaluate the application efficiency with reduced volume from the prototype of a pneumatic spray nozzles aimed to control the coffee leaf miner (Leucoptera coffeella). We evaluated different types of pneumatic nozzles (flat fan, cone jet, AT-1000 model and effervescent), on application of insecticide spray liquids with concentrations of 5, 10, 15 and 20% (v/v) of mineral oil applied in reduced volume and 0.5% applied by conventional airblast sprayer. The application technology parameters studied in laboratory and field conditions were as follows: droplet size (µm), tracer deposit (µg/cm²) and leaf spray coverage (%). The reduced volume application, provided by the prototype of a pneumatic spray nozzles with the effervescent type compared to traditional airblast sprayer, presents proper conditions of use, especially in relation to deposit and coverage of spraying liquid over coffee leaves.