Sensor-controlled site-specific herbicide application system for irrigated cotton production

Overview

This research addresses the substitution of energy-intensive agricultural inputs with information-intensive digital tools by developing a sensor-controlled, site-specific herbicide application system for irrigated cotton production. Conventional practice applies herbicide uniformly across the field, wasting chemical, money, and contributing to environmental degradation and herbicide-resistant weed populations. The proposed solution uses smart sensors to detect the presence of weeds in real time and trigger actuation commands that deliver herbicide only where weeds are identified. The result is a more economical and environmentally responsible approach to weed control that also reduces the biological pressure driving herbicide resistance.

Technical specifications

Core technology:

• Real-time weed detection sensors mounted on a field sprayer
• Smart controller that generates actuation commands based on sensor input
• Spot-treatment nozzle system that delivers herbicide only to detected weed locations

Key research variables under investigation:

• Biological settings including weed species composition, spatial distribution, and weed density
• Engineering parameters including sensor sensitivity, field of view, and operational speed
• Shielding configurations: a conventional approach that shields sensors inside furrow-running hoods versus an innovative approach that shields the crop plants while fully exposing the furrow area to the sensors

Expected advantages of the innovative shielding approach:

• Improved weed detection with a reduced number of sensor units
• Better nozzle positioning for higher machine performance
• Greater weed control efficacy

Technology readiness level

The technology has progressed beyond initial concept validation. In 2020, University of Arizona Extension faculty conducted field experimentation in irrigated cotton to test the limits of sensor-controlled herbicide application under varying biological and engineering conditions. Preliminary results indicate that weed control efficacy is heavily dependent on sprayer configuration and shielding approach. Current and future work focuses on replicated field trials that combine biological variations in weed populations with a range of operational sprayer parameters, directly comparing the conventional hood-based shielding method to the innovative crop-shielding approach. The goal is to identify optimal configurations for irrigated production systems and advance the technology toward broader adoption.