The 2011 ASHS Annual Conference

A commercial prototype variable rate (VR) sprayer was developed for control of 16 individual nozzles on a 12.2 m sprayer boom for spot-application of agrochemicals in wild blueberry fields. The sprayer boom was divided into 16 sections and was situated 76 cm above the ground. The variable-rate control system consisted of eight digital color cameras mounted on a separate boom in front of the tractor, a MidTech Legacy controller, flow valves, solenoid valves and two 8-channel variable rate controllers (VRC) interfaced to a Pocket PC using wireless Bluetooth^® radio with Windows Mobile^® compatible software. Each camera covered two sections of the boom (97 cm each section). Cameras were attached using USB serial cables to the computer. Custom developed software, installed in the computer, was capable of processing the images to detect weeds, bare spots and blueberry plants in real-time, and weed or plant triggering signals were sent through a labjack actuator to the VRC to spray agrochemical in the specific boom section where the weeds or plants have been detected. The commercial prototype VR sprayer was tested and evaluated in wild blueberry fields in central Nova Scotia for precise spot-application of herbicides and fungicides.  Accurate and precise applications were obtained, significant reductions in herbicide and fungicide applications were observed and substantial cost savings were attained.