Performance and Evaluation of Intra-Row Weeder Ultrasonic Plant Detection System and Pinch-Roller Weeding Mechanism for Vegetable Crops

Abstract. Weed control is a tedious task, especially in organic crop production where synthetic herbicides are prohibited and manual weeding is relatively costly or unavailable. However, automated mechanical intra-row weed control is an option that can be implemented to control weeds in the centerline of a crop row. The goal of this project was to develop and evaluate the performance of a prototype intra-row mechanical weed control system that uses a rotating pinch-roller weeding mechanism to control weeds within crop plants. A real-time plant detection system based on ultrasonic sensing system was used to detect the location of crop plants and control the operation of the weeding mechanism between crop plants along the centerline of the crop row. Two field

experiments were conducted to evaluate the accuracy of the ultrasonic plant detection system and to evaluate the performance of the pinch-roller weeding mechanism. The results of the first experiment showed a significant slope (p<.0001) with model had an R² of 0.94 between the sensor-estimated and manual height measurement of crop plants in the field. The second experiment showed there was a significant difference in weed control efficacy between weed species (P=0.03). The Southern crabgrass, with weed control efficacy of 33.9%, was more effectively controlled than Florida pusley in which the control efficacy was only 4.4%, yet was not significantly different from benghal dayflower (18.3%) and purple nutsedge (5.4%). No significant effects were found among the pinch-roller rotational speed and travel speed.