Validation of laser-guided variable-rate sprayer for managing insects in ornamental nurseries

Authors: Zhu, Heping; ROSETTA, ROBIN - Oregon State University; Reding, Michael - Mike; ZONDAG, RANDY - The Ohio State University; Ranger, Christopher; CANAS, LUIS - The Ohio State University; FULCHER, AMY - University Of Tennessee; Krause, Charles; Derksen, Richard; OZKAN, ERDAL - The Ohio State University

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2017
Publication Date: 5/25/2017
Publication URL: https://handle.nal.usda.gov/10113/5801822
Citation: Zhu, H., Rosetta, R., Reding, M.E., Zondag, R., Ranger, C.M., Canas, L., Fulcher, A., Krause, C.R., Derksen, R.C., Ozkan, E. 2017. Validation of laser-guided variable-rate sprayer for managing insects in ornamental nurseries. Transactions of the ASABE. 60(2): 337-345.

Interpretive Summary: To ensure high quality and maximize the number of marketable plants per acre, pesticides will continue to be used for the majority of specialty crop production in the foreseeable future. However, current pesticide spray technologies frequently result in over-application and excessive off-target losses and spray drift, primarily due to large variations in canopy size, leaf density, plant spacing, and constant application rate discharged by conventional sprayers. This low efficiency has caused an enormous amount of pesticide waste, additional costs in crop production and great concerns on environmental contamination. To address these problems, a laser-guided precision spraying system was recently developed by USDA-ARS researchers along with their collaborators. This sprayer could automatically detect the presence of target plants, and measure their size, shape and foliage density as well as the sprayer travel speed in real time and then automatically calculate the spray volume for pesticide applications. Unfortunately, adoption of new spray technologies is complicated by trade-offs among competing economic and environmental interests of growers, sprayer manufacturers, pesticide manufacturers, and regulating agencies. To ensure that the new laser-guided sprayer system will reliably and effectively control pests while significantly reducing pesticide and spray application costs, tests of the system must be conducted and compared with conventional sprayers for pest control effectiveness under on-farm field conditions. In this research, efficacy of insect control measures was compared between the laser-guided sprayer and conventional air-assisted sprayers in commercial ornamental nurseries in Ohio and Oregon. The laser-guided sprayer used only 22% to 70% insecticide spray volume of conventional sprayers and still achieved comparable and acceptable level of insect pest controls. These test results demonstrated the superior efficacy of this enhanced variable-rate spray technology to control insect pests with reduced pesticide use while protecting the environment.

Technical Abstract: Conducting on-farm evaluations of pest control and economic feasibility is a necessary procedure to assure successful adoption of new spray technologies by commercial horticulture enterprises. A newly developed laser-guided air-assisted variable-rate sprayer was tested for control of spirea aphids (Aphis spiraecola), pod gall midges (Dasineura gleditchiae), and pear sawflies (Caliroa cerasi) on crabapple (Malus species), ‘Sunburst’ honey locust (Gleditsia triacanthos inermis) and ‘Mazzard’ cherry (Prunus avium) trees, respectively in three commercial nurseries in Ohio and Oregon. Efficacy of pest control treatments applied by the laser-guided sprayer was compared with those from two conventional air-assisted tower sprayers and an axial-fan radial air-blast sprayer. During the tests, the spray volume discharged from the laser-guided sprayer was adjusted automatically based on the plant presence, canopy structure and foliage density. The application rates for the conventional sprayers were determined to comply with best pest management practices. Compared to conventional sprayers with comparable and effective insect control, the laser-guided sprayer reduced spray volume by 60% and 36% to control aphids in nursery #1 and nursery #2, respectively. Similarly, in nursery #3 the laser-guided sprayer used 77.6% and 29.7% less spray volume and chemicals to control pod gall midges and sawflies, respectively. Thus, the new variable-rate spray system reduced pesticide use, increased pesticide spray application efficiency, and improved profitability, thereby offering an economically and environmentally responsible approach to controlling pests.