Design and Field Evaluation of an Automatic Inter and Intra-row Weeder for Wide-spaced Crops

Abstract

Manual weeding is labour-intensive and time-consuming while inter and intra-row weeders significantly reduce the labor required for weed management, allowing farmers to allocate their time and effort to other important farming activities. A tractor-mounted automatic inter and intra-row weeder was developed to address the challenges of labour-intensive weed management in wide-spaced crops such as cotton. The machine integrated a pivoting arm, rotary blades, ultrasonic sensors, and a microcontroller-based control system for precision weeding. The intra-row blade was actuated by a geared DC motor, while the inter-row blade was driven using the tractor power take-off (PTO). Field experiments were conducted at Dr. NTR College of Agricultural Engineering, Bapatla, on sandy loam soil with three plant spacings (45, 50, and 60 cm), three tractor forward speeds (1.5, 2.0, and 2.5 km/h), and three-blade rotational speeds (180, 220, and 260 rpm). Performance was evaluated based on weeding efficiency, plant damage, and field capacity. The highest weeding efficiency (85%) was observed at 60 cm spacing with a speed-blade combination of S1B3 (1.5 km/h and 260 rpm), while the lowest plant damage (8%) occurred with S1B1 (1.5 km/h and 180 rpm). Wider plant spacings consistently resulted in better performance due to improved manoeuvrability and reduced crop interference. The results demonstrated that the developed prototype could significantly enhance weed control with minimal crop damage and improved operational efficiency, making it a viable solution for precision agriculture in wide-row cropping systems.