Nozzle and spray volume effects on site-specific quinclorac applications in turfgrass using a remotely piloted aerial application system

Authors: COSTA, AUGUSTO - Brazilian Agricultural Research Corporation (EMBRAPA); Martin, Daniel; TORRES, UBALDO - Texas A&M University; STRAW, CHASE - Texas A&M University; FLOYD, WESTON - Texas A&M University; Fritz, Bradley; BAGAVATHIANNAN, MUTHUKUMAR - Texas A&M University

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2025
Publication Date: 3/4/2025
Citation: Costa, A.F., Martin, D.E., Torres, U., Straw, C.M., Floyd, W., Fritz, B.K., Bagavathiannan, M. 2025. Nozzle and spray volume effects on site-specific quinclorac applications in turfgrass using a remotely piloted aerial application system. Weed Technology. 39(e43): 1-9. https://doi.org/10.1017/wet.2025.15.
DOI: https://doi.org/10.1017/wet.2025.15

Interpretive Summary: Traditional herbicide applications for weed control in turf involve broadcast applications over a large area. When weed densities are low, this results in wasted product and increases chemical costs and environmental loading. Field studies were conducted with a spray drone to make targeted herbicide applications for control of crabgrass in turf. The drone provided equivalent control of crabgrass at 1 gallon per acre to that of a backpack application at 10 gallons per acre. These findings can help provide turf managers with a better understanding of how drones can be effectively utilized for targeted control of weeds in turf.

Technical Abstract: Site-specific herbicide sprayings with remotely piloted aerial application systems (RPAASs) offer the potential for reducing herbicide inputs in turfgrass systems, where treatments can be targeted specifically to weeds and weed infestations rather than broadcast across an entire area. However, information on spray nozzle selection and application volume for this approach is lacking. The objective of this study was to evaluate nozzle type and spray volume effects on the efficacy of site-specific quinclorac applications, using an RPAAS, for large crabgrass control in turf. The research was conducted in 2022 at two locations in College Station, TX. The treatments were combinations of three nozzle types [XR 80-015 (conventional, extended range), DG 80-015 (drift guard), and AI 80-015 (air induction) flat fan nozzles] and three spray volumes [10 and 15 L ha-1, applied with a single nozzle RPAAS, and 102 L ha-1 applied with a CO2 pressurized 4-nozzle boom backpack sprayer]. Two additional treatments were included: a pure formulated herbicide application (without dilution in water) using an RPAAS equipped with an XR 80-005 flat fan nozzle at 4.6 L ha-1 and an untreated control. The backpack sprayer application resulted in the highest spray solution deposits on large crabgrass plants (twelve times more, on average), compared to the RPAAS applications. Spray applications with the DG and AI nozzles using the RPAAS at 10 and 15 L ha-1, or backpack sprayer at 102 L ha-1, provided similar weed control, indicating that RPAAS-based herbicide applications can be effectively made using a range of application parameters. This study suggests that control of large crabgrass can be achievied using RPAAS herbicide treatment applications with a range of spray nozzle types at low application volumes in turfgrass. Nevertheless, further research is warranted to assess the efficacy of this approach across various weed species and under diverse environmental conditions.