Tests at the USDA’s facility in Texas look at how any differences, such as nozzle size and position as well as operating height and speed impact spray quality.
Actual working width Lastly, operators also need to know the actual working width. “Swath width is determined not only by the nozzle spacing, but also by the type of aircraft. It could also be affected by the working height as well as the speed. So we carried out applications at three heights: 2m, 3m and 4m,” he explains. Slower speeds had little effect on the swath but greatly impacted the application rate. Application heights of 2m and 3m allowed for the spray pattern to mature while still miti- gating drift by staying closer to the ground. Tests indicated that effective swath was most effected by nozzle (fine, medium, coarse) and the size of aircraft. Tests were carried out at the three application heights, at the four ground speeds and with four repetitions. Each was also tested with three different nozzles, to check the swath width, coverage and drift and assess the dif- ferent droplet spectra. These included a fine nozzle XR 110 01 (about 200-250 microns), the medium TeeJet TT 110 01 (300-350 microns @ 2.0 to 3.5 bar) and a medium-to- coarse Lechler IDK 110 01
(350-400 microns @ 3.0-6.0 bar). Droplets were collected on water-sensitive paper to assess the drop size, number and coverage in order to characterise the droplet spectrum.
Dramatically cutting drift “The results were very clear: you can dramati- cally cut drift by simply selecting the right noz- zle. This confirmed our initial idea that we were expecting to see less drift from the medium
US regulators help drone spraying to take off
By modifying existing rules for manned aerial applications USA regulators have quickly in- troduced new regulations to cover spraying from unmanned aerial vehicles (UAVs) – commonly called drones. Operators need to acquire two documents from the Federal Avi- ation Authority (FAA), for an unmanned re- mote pilot certificate and for aerial pesticide applications. And they must apply for ex- emptions for unmanned operation. Drone sprayer pilots also require an agricultural cer- tificate from the state where they operate.
These rules apply to drones under 55 lbs (25 kg), which can only be operated in visual line of sight (VLOS). Further rules apply to larger models. In July 2019, Rantizo was the
A 3m application height is considered ‘the sweet spot’ for drone spraying.
first company to be authorised to apply pesti- cides from the air in its home state of Iowa. A year later, it obtained the first and only au- thorisation to operate a swarm of up to three drones with one pilot and one visual observer in all 48 states (but not in Alaska and Hawaï).
▶ FUTURE FARMING | 20 November 2020 55
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
