Impact of sprayer drone flight height on droplet spectrum in mountainous coffee plantation

Abstract

Weather conditions and sprayer operating parameters influence spray quality. Unmanned aerial vehicles are considered a modern, useful, and very efficient technological tool in the application of pesticides, as they carry out punctual spraying, and reduce environmental and public health problems. The objective of this study was to characterize the spraying quality carried out with an unmanned aerial vehicle as a function of flight height and target position in a coffee plantation in a mountainous region. Three flight heights (2.5, 3.0, and 4.0 m) were used, and the targets were placed at the top and bottom of the plant. For each plant, six water sensitive papers were placed on top of the plant and six were placed at the bottom. CIR 1.5 software was applied to determine the coverage percentage, drop density, volume median diameter, volumetric diameter corresponding to 10 and 90%, numerical median diameter, and relative amplitude. The results showed that the flight height only influenced the parameters of the volumetric diameter corresponding to 10% of the volume, numerical median diameter, and coverage percentage. The target position on the canopy influenced all the evaluated spraying parameters. In mountainous coffee plantations, the spraying system using unmanned aerial vehicle spraying is more efficient for the lower part of the plant.

Efficiency of Fungicide Application an Using an Unmanned Aerial Vehicle and Pneumatic Sprayer for Control of Hemileia vastatrix and Cercospora coffeicola in Mountain Coffee Crops

“…The mean coverage, density, and deposition of droplets significantly increase as the application rate is increased. Similar results were found in similar experimental studies on conilon coffee [5], arabica coffee [6], citrus [24,25], apple [2,3], wheat [17], and rice [16] crops. Two aspects are considered important for fungicide application to coffee arabica crops using a UAV: the first is the low operational capacity due to the limited tank load and low battery charge duration [15,29] and the second is the characteristic place of infestation of most fungal diseases in conilon coffee crops, which is usually in the middle and upper canopy layers [30,31]; the results indicate the use of an application rate of 10 L ha −1 .…”

“…The yield of coffee crops depends on several factors, such as climate changes, genetic and nutritional developments, water availability and use efficiency, and plant health protection. Regarding plant health protection, there were significant advances in the technological development of selectivity and efficacy of pesticides; however, the pesticide application technology connected to this development did not follow the same pace, and in the specific case of coffee crops, pesticide applications have usually been inefficient [5,6]. The pesticide application technology for coffee crops should be well managed to avoid losses of product to non-target areas; therefore, the target position, architecture of coffee plants, climate conditions, nozzle positioning, and regulation and calibration of sprayers should be considered [7,8].…”

Economic Injury Levels and Economic Thresholds for Leucoptera coffeella as a Function of Insecticide Application Technology in Organic and Conventional Coffee (Coffea arabica), Farms

“…Research into the costs of applications by tractor, manual and airplane were carried out due to these being the main technologies used in pesticide applications on coffee crops [ 31 , 32 ]. The research into the costs of applying insecticides by drones was carried out due to this being a modern and promising technology for applying pesticides [ 13 ]. In conventional crops, applications of insecticides via soil can be carried out manually or with a tractor, with only one application being made.…”

“…These applications can be carried out manually, or using a tractor or plane [ 12 ]. Recently, drones have also been used to apply pesticides to coffee crops [ 13 , 14 ].…”

“…Furthermore, when there is a need to control pests in large flat areas quickly, pesticide applications are carried out by plane [ 20 , 21 ]. Drones are a modern technology that can be used in both flat and mountainous areas [ 13 , 14 ].…”