VALIDATION OF A LASER-GUIDED VARIABLE-RATE SPRAYER FOR MANAGING INSECTS IN ORNAMENTAL NURSERIES

Conducting on-farm evaluations of pest control and economic feasibility is a necessary procedure to ensure successful adoption of new spray technologies by commercial horticulture enterprises. A newly developed laser-guided variable-rate air-assisted 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. The efficacy of the laser-guided sprayer for pest control treatment was compared with the efficacy of two types of conventional constant-rate air-assisted sprayers. During the tests, the variable rate from the laser-guided sprayer was achieved automatically based on 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 the conventional constant-rate sprayers with comparable and effective insect control, the laser-guided sprayer reduced the spray volume rate to control aphids by 60% and 36% in nurseries 1 and 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 insect pests.