Biological Response from Field Application Trials of Targeted, Pulsed-Jet Microsprayers

Methods such as image analysis and spectral discrimination are being developed to detect and locate individual weeds, often in close proximity to crop plants. The subsequent treatment of small, distinct targets requires liquid dosing systems capable of high spatial resolution and rapid response time. A pulsed, micro-jet sprayer was developed. Field tests assessed biological performance of the micro-spray technique with nonselective herbicide formulations including surfactants and polymer adjuvants. Liquid dose rates were on the order of 40 µl/cm2 for treatment areas down to 6.5 mm x 12.5 mm using a 6 ms pulse duration. An optimal formulation of surfactant and polymer was found to increase efficacy while reducing phytotoxicity, through splash, to adjacent plants. These results suggest that use of non-selective herbicides for micro-scale spraying of weeds during early crop growth is possible. Future work will use the results as part of the decision criteria within a machine vision weed identification system for targeting weeds and spatially selective application of herbicides.