Effect of air-assistance configuration on spray recovery and target coverage for a vineyard sprayer

摘要

A new approach for a spray recovery sprayer (SRS) was developed for apple orchards (Panneton et al. 2001) and has been adapted to vineyards (Panneton et al. 2003). The vineyard version used two vertical air sleeves to create two air jets, one on eachside of the row. The sprayer was equipped with an air-droplet separator for spray recovery. This work aimed to define the effect on spray coverage and spray recovery potential of' different air jet angles relative to the row of vines, sprayer ground speed, and the partition of the air flow rate between the two air sources. Each variable was set at two levels to define a full factorial experiment with three replications. Spray coverage was measured on water sensitive paper targets and spray recovery wasdefined as the ratio of the amount of spray collected to the total amount of liquid emitted by the nozzles for each treatment. Results showed that the orientation of the air sources had a significant effect on both spray coverage and spray recovery. In the centre of the row, decreasing the sprayer ground speed improved coverage. For spray recovery, the distribution of the total air flow rate among the two sources was the most important variable. The best compromise for coverage and recovery was to partition total air flow rate such that 35% was emitted from the sleeve on the sprayer side and to direct this source of air at an angle of 45° to the row and to operate the sprayer at the lowest ground speed (4.4 km/h).