Location: Application Technology Research Unit
Title: Spray drift and off-target loss reduction with a precision air-assisted sprayer Authors
Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 6, 2013
Publication Date: December 22, 2013
Citation: Chen, Y., Zhu, H., Ozkan, H.E., Derksen, R.C., Krause, C.R. 2013. Spray drift and off-target loss reduction with a precision air-assisted sprayer. Transactions of the ASABE. 56(6)1273-1281. Interpretive Summary: Conventional sprayers for pesticide spray applications discharge substantial off-target losses and airborne drifts that contaminate the air, soil, and ground water and poses health threats to humans and livestock. A variable-rate precision sprayer integrated with a laser scanning sensor was developed and evaluated to reduce the spray losses on the ground, in the air, and around trees at different plant phenological stages in an orchard. The tests were also compared with two conventional constant-rate applications. Compared to the conventional spray applications during the growing season, the newly developed precision sprayer reduced the average amounts of spray losses of the constant-rate sprayers on the ground by 83%, airborne drift by 84%, and spray volume by 63%. Therefore, the new sprayer significantly outperformed the constant-rate sprayers, increased pesticide application accuracy and minimized off-target losses and spray drift for orchard and nursery applications, and could bring real benefits to growers economically and environmentally.
Technical Abstract: Spray drift and off-target losses are inherent problems of conventional air-assisted sprayers. Their low efficiencies cause environmental pollutions resulting in public anxieties. A new drift reduction technology incorporating laser scanning capabilities with a variable-rate air-assisted sprayer was developed to address these problems, and tested in an apple orchard. This new sprayer, the same sprayer with the variable-rate function disabled, and a conventional constant-rate air-blast sprayer were the three test treatments for comparison. Tests were conducted at beginning to leafing, half-foliage, and full-foliage growth stages. Spray deposits from spray drift and off-target losses were collected within tree rows at ground level, above and behind the sprayed trees, gaps between two trees, and from 3.2 m tall poles at 5, 15, and 35 m from the tree rows. Compared to the constant-rate sprayer, the laser-guided variable-rate sprayer reduced average spray losses on the ground by 68% to 90% and around tree canopies by 70% to 92%, airborne spray drift by 70% to 100%, and most importantly, the spray volume by 47% to 73%, while their spray deposition qualities inside canopies for these sprayers were comparable. These results demonstrated that the innovative laser scanning technology incorporated into the variable-rate sprayer reduced spray drifts and off target losses of pesticides, was environmentally sustainable, and economically beneficial to growers.