Basavaraj R. Amogi

This study developed and evaluated an algorithm for processing thermal-RGB video feeds captured by an unmanned aerial vehicle (UAV) to automate heat stress monitoring in cattle housed in the drylots. The body surface temperature (BST) of individual cows was used as an indicator of heat stress. UAV data were collected using RGB and thermal infrared imagers, respectively, at 2 and 6.67 cm per pixel spatial resolution in Spring 2023 (dataset-1) and Summer 2024 (dataset-2). Study sites were two commercial drylots in Washington State. The custom algorithms were developed to: (1) detect and localize individual cows using a Mask R-CNN-based instance segmentation model combined with centroid tracking; and (2) extract BST by averaging the thermal-imagery pixels for each of the segmented cows. The algorithm showed higher detection accuracy with RGB images as input (F1 score: 0.89) compared to thermal (F1 score: 0.64). BST extraction with combined RGB and thermal imaging approach required corrections for alignment problems associated with differences in optics, imaging field of view, resolution, and lens properties. Consequently, thermal imaging-only approach was adopted for assessing real-time cow localization and BST estimation. Operating at one frame per second, algorithm successfully detected 72.4% and 81.65% of total cows in video frames from dataset-1 (38 s) and -2 (48 s), respectively. The mean absolute difference between algorithm output and ground truth (BST_GT) was 2.1 °C (dataset-1) and 3.3 °C (dataset-2), demonstrating satisfactory performance. With further refinements, this approach could be a viable tool for real-time heat stress monitoring in large-scale drylot production systems.

Background and goals Ozone (O₃) is a powerful oxidizer. When dissolved in water, O₃ offers a direct, residue-free application to potentially control unwanted pests. Ozonated water spray (OWS) has been shown to suppress powdery mildew growth in greenhouse settings and cause insect mortality under in vitro conditions. Our goal was to evaluate the ability of OWS in lab and field settings to manage two main pests in eastern Washington vineyards: grapevine powdery mildew (Erysiphe necator) and grape mealybug (Pseudococcus maritimus). Methods and key findings The potential curative effects of ozonated water on nascent E. necator colonies and its lethal effects on P. maritimus nymphs were evaluated using O₃ concentrations of 1 or 7 mg/L, delivered through a laboratory OWS system. These studies were coupled with field evaluations using a commercial OWS retrofit system to manage E. necator prebloom and P. maritimus as a delayed-dormant treatment. Our lab studies against E. necator confirmed that OWS was not effective at reducing colony formation. Due to low disease pressure years during the study, we cannot confirm the field efficacy of OWS applied prebloom. Laboratory-scale OWS was inconsistent at increasing P. maritimus nymph mortality. OWS field evaluations for P. maritimus management did not reduce the nymph population. Conclusions and significance Current OWS systems are not an effective tool for E. necator and P. maritimus management when applied at the O3 concentrations that current commercial units can generate.