Abstract
ABSTRACT Spray distribution generated by axial fan sprayer, among other factors, should be critically analyzed, in order to prevent unnecessary costs and environmental contamination. This study aimed at evaluating the effect of the vertical volumetric distribution of an axial fan sprayer on the Brevipalpus phoenicis control efficiency. First, an assay was performed to evaluate the vertical volume distribution uniformity of the sprayer, assessing different spray nozzles configurations on the spray arcs, sides of the sprayer and spray heights. Afterwards, another experiment was carried out to analyze the relationship between the distribution of the Fenpyroximate acaricide on Coffea arabica L. and the B. phoenicis control efficiency. The treatments were arranged in a 4 x 2 factorial + 1 additional control, consisting of four spray volumes (200 L ha-1, 400 L ha-1, 600 L ha-1 and 800 L ha-1) and two spray nozzles configurations (1: 100 % of MAG1.5 nozzles; 2: upper extension with 5 MAG3.0 nozzles, middle extension with 9 MAG1.5 nozzles and lower extension with 4 MAG3.0 nozzles). Configuration 2 provided the smallest coefficient of variation (28 %). Nozzle configurations had no effect on the incidence of B. phoenicis. The use of nozzles with different flow rates on the spraying arc improves the vertical volumetric distribution uniformity of axial fan sprayers, but does not affect the B. phoenicis control efficiency.
Highlights
Coffee production is a very important activity for the Brazilian agribusiness, where coffee is one of the major commodities
The working principle of this sprayer is based on the fragmentation of pressurized liquid into droplets that are released into a high flow and velocity air stream
For configuration 1, the left side of the spray arc resulted in a coefficient of variation (CV) of vertical volumetric distribution 22 % smaller than the right side (Table 2)
Summary
Coffee production is a very important activity for the Brazilian agribusiness, where coffee is one of the major commodities. Estimated domestic production from the 2015 harvest is 1,878 t (31.3 million bags) of processed Arabica coffee (Conab 2015). In order to reach high yields, it is necessary to adopt various technologies, including the application of pesticides via axial fan sprayer. The working principle of this sprayer is based on the fragmentation of pressurized liquid into droplets that are released into a high flow and velocity air stream. The high pressure air stream promotes new fragmentation, carrying the droplets to the plant canopy, even at hard-to-reach targets (Ruas et al 2015). The airflow produced by axial fan sprayers is usually distributed unevenly along the fan outlet (Rodrigues et al 2008)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
