Editorial: Innovative technology and techniques for effective weed control

Frontiers in Agronomy · 2026-01-23

With the rapid increase in drone adoption, the global agricultural drone market is forecasted to grow to $11.9 billion USD by 2028 from an approximate worth of $1.4 billion USD in 2021 (Research and Markets, 2023). Butts et al. explored the combined effects of various hydraulic nozzle types and spray volumes on coverage and deposits from remotely piloted aerial application systems (spray drones). They observed increased spray recovery in the center of the spray swath compared to ground spray equipment, and identified specific nozzles to improve deposits while mitigating off-target movement potential. Paul et al. observed similar weed control in rice from a spray drone application compared to a knapsack manual sprayer despite significant reductions in spray volume, coverage, and droplet deposits. Their findings highlighted the potential of spray drones to reduce both labor and pesticide exposure in direct-seeded rice production.Proper weed identification is a critical first step towards effective weed management efforts. Venkataraju et al. explored multiple algorithms, including machine learning, deep learning, and object detection, to correctly identify troublesome weeds such as Palmer amaranth (Amaranthus palmeri S. Wats.) and waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer]. Their deep learning model was most successful, achieving 93% accuracy in identifying the two species.Innovative techniques also involve viable strategies for improving future weed management efforts. Somala et al. explored the capabilities of a fungal extract (Diaporthe spp.) to reduce growth characteristics of barnyardgrass (Echinochloa crus-galli P. Beauv.). Their laboratory research demonstrated greater than 80% reduction in barnyardgrass seed germination, root length, and shoot length. In other laboratory allelochemical research, Trespidi et al. identified that root exudates from Baccharis halimifolia L. reduced germination by 50-75% and reduced root length by more than 85% across all tested species. However, they noted the challenges of consistently translating laboratory allelochemical results to field applications, and thus further research is needed to refine the use of allelochemicals for effective weed management. Niklolić et al. investigated biological characteristics, including germination thresholds and seed properties, of common ragweed (Ambrosia artemisiifolia L.) across different European climatic conditions. Their research demonstrated high adaptability of common ragweed to varying weather patterns, further exemplifying the need for site-specific weed management strategies.Finally, understanding practitioners' perceived needs, current practices, and thoughts about novel technologies is vital for establishing stakeholder-driven research and providing meaningful outreach. Ugljic et al. surveyed 128 stakeholders across the U.S. Midwest to assess these values. Results revealed more than 75% of respondents were unsure of adopting innovative targeted spray technologies. Survey results also showed that nearly 50% of respondents indicated they needed additional information on targeted spray equipment, underscoring the importance of further innovative technology research in conjunction with effective outreach efforts.This collection of research works serves as a critical example of the innovative weed management research being conducted globally, and the need for continued exploration. Longterm career forecasts have predicted that there will be a need for professionals who understand weed biology, ecology, and management principles, while simultaneously comprehending sensors, automation, and engineering technologies (Westwood et al., 2018). Additional funding resources and support are also required in this critical agricultural research crossroad. Collaborations with industry partners are a necessity, but there is also a pressing requirement for state, federal, and international funding resources to evaluate innovative weed management technologies and techniques. These novel tools will be released commercially regardless of the research background; therefore, funding not tied to a specific company will be crucial to validate marketing claims, supply non-biased data, and disseminate recommendations through engagement and Extension outreach for the successful implementation of these tools.

Targeted herbicide cost requirements for adoption of See & Spray technology and ways to improve area sprayed

Agrosystems Geosciences & Environment · 2026-02-28

Abstract Adopting targeted herbicide applications creates a dynamic problem for producers when considering the economic viability of See & Spray. Research was conducted to estimate how weed area, area sprayed, nozzle selection, sensitivity settings, crops, and regions influence potential herbicide savings with the John Deere See & Spray technology. From 2023 through 2024, producers covered over 510,000 ha and sprayed 212,000 ha with See & Spray technology in the United States. Ways to improve herbicide savings via See & Spray included using narrow nozzle angles rather than wider fan angles and adjusting the sensitivity setting to detect less weed area. Cotton ( Gossypium hirsutum L.) had a higher weed area than soybean [ Glycine max (L.) Merr.; 16.6% vs. 5.1%]. Lower sensitivity settings tended to detect less weed area than higher settings (5.1% at the lowest setting, 9% at the medium setting, and 15.8% at the highest setting). On average, producers needed to spend >$27 ha −1 on herbicides in a single application with See & Spray Premium and >$39 ha −1 with See & Spray Ultimate to economically justify using the technology over a broadcast sprayer. Results indicate that differences in targeted herbicide cost requirements to break even were within $1–$2 ha −1 across regions and within a crop and technology. Ways to improve areas sprayed with targeted applications, factors to consider before application, and insights on ensuring producers’ profitability when adopting this technology are highlighted.

Influence of saflufenacil encapsulation on corn phytotoxicity and residual broadleaf weed control

Weed Technology · 2026-01-01

Abstract Saflufenacil, a herbicide that inhibits protoporphyrinogen oxidase, has been reformulated as a microencapsulation for preemergence and postemergence applications to corn, with the primary purpose of the encapsulation to reduce the risk of corn injury from foliar applications. Field experiments on corn were conducted in 2023, 2024, and 2025 to evaluate the efficacy of encapsulated saflufenacil alone and in the formulated premixture with pyroxasulfone for residual broadleaf weed control and crop injury. Applications of encapsulated saflufenacil across a dose range resulted in incomplete control (less than 60%) of giant ragweed. Combinations of the encapsulated saflufenacil + pyroxasulfone premixture with atrazine were efficacious in controlling giant ragweed up to 28 d after planting (DAP), but efficacy declined sharply by 42 DAP. The reduced efficacy on giant ragweed was attributed to a lack of an activating rain for the encapsulated saflufenacil. Conversely, encapsulated saflufenacil applications, with or without pyroxasulfone, were highly efficacious (83% to 99% control) on waterhemp and common lambsquarters, two small-seeded broadleaf species. Furthermore, the most extensive weed control with encapsulated saflufenacil resulted from sequential applications (preemergence and postemergence) of a residual herbicide. Overall, encapsulated saflufenacil was effective in controlling small-seeded broadleaf weeds until a postemergence herbicide was applied. However, additional herbicides in a mixture may be needed to manage large-seeded broadleaf species such as giant ragweed. Regardless of the target species, management of problematic, herbicide-resistant weeds with encapsulated saflufenacil should focus on combinations with other effective herbicides in both preemergence and postemergence applications, in addition to other weed control tactics.

Drone-Based Herbicide Application: Opportunities and Challenges

Weed Technology · 2026-02-26

Abstract Advancements in precision agriculture have driven the development of spray drones for herbicide application, offering the potential to address challenges associated with current application methods and improve weed management. This review synthesizes current research on spray drones to develop broad-use recommendations and identify challenges and knowledge gaps. Although spray drones use lower carrier volumes than ground-based sprayers (high-volume backpack or tractor-mounted sprayers), studies report comparable or superior weed control as well as herbicide cost savings. However, spray drone performance is highly sensitive to operational parameters, as spray distribution and coverage/deposition are strongly affected by flight height and speed, carrier volume, nozzle design, crop growth stage, weed, and weather conditions. The bell-shaped curve of a single-pass spray pattern, which results in most spray deposition occurring directly under the unmanned aerial vehicle (UAV), coupled with advances in imaging, remote sensing, and machine learning, demonstrate the strong potential of spray drones for site-specific weed management. Vegetation indices, multispectral imagery, canopy height models, and Light Detection And Ranging (LiDAR) technology have enabled crop-weed discrimination, though accuracy varies with species, growth stage, and image resolution. Deep-learning models such as ‘You Only Look Once’ (YOLO), Residual Neural Network (ResNet) and Mask Region-based Convolutional Neural Network (Mask R-CNN) achieve high performance for weed detection and/or segmentation but remain limited by training data quality and reduced accuracy with small, overlapping, or dense weed populations. Spray drone-based offline mapping has enabled substantial herbicide savings by delineating weed patches, whereas real-time weed detection is constrained by onboard processing limits, battery life, and lower spatial resolution at operational flight heights. Ground-based smart sprayers offer higher real-time detection precision but lack the field accessibility advantages of spray drones. Despite their potential, spray drones face challenges, including limited payload, off-target movement of pesticides, short battery life, regulatory challenges, and extensive license and complex software and calibration requirements. The downwind spray drift potential of spray drones is greater than ground applications but smaller than manned aerial applications. An upwind swath offset is an ideal best management practice to reduce off-target pesticide movement to susceptible areas from both manned and spray drone equipment. Future research should evaluate spray drones within integrated weed management systems, focusing on preemergence and foliar-applied contact herbicides, adjuvant use, environmental and operational interactions to develop spray drone-specific guidelines and optimize spray performance.

Performance of an <i>S</i> ‐metolachlor capsule suspension for barnyardgrass control and crop tolerance in fenclorim‐treated rice

Agrosystems Geosciences & Environment · 2026-04-12

Abstract Barnyardgrass [ Echinochloa crus‐galli (L.) P. Beauv.] is the most problematic weed of delayed‐flooded rice ( Oryza sativa L.) systems in the mid‐southern United States. Recent findings suggest that acetochlor can achieve effective barnyardgrass control in rice, but rice injury can occur with rainfall soon after application. The use of a herbicide safener such as fenclorim can reduce the risk of rice injury to acetochlor and possibly other chloroacetamide herbicides. An experiment was conducted on clay soil with S ‐metolachlor applied from 0 to 1.68 kg a.i. ha −1 with a fenclorim seed treatment at 0 and 2.5 g a.i. kg −1 seed at a delayed‐preemergence (DPRE) application timing in rice. Another experiment was conducted on a silt loam soil with S ‐metolachlor applied from 0 to 0.84 kg ha −1 DPRE or one‐leaf on fenclorim‐treated rice. In 2022, on the clay soil, S ‐metolachlor at 0.56 kg ha −1 provided greater than 90% barnyardgrass control with less than 20% rice injury at 28 days after treatment. However, in 2023, wet conditions delayed the application, resulting in increased emergence of barnyardgrass before treatments could be applied. On a silt loam soil in 2023, crop safety improved when S ‐metolachlor was applied DPRE and rice was treated with fenclorim compared to the nontreated seed; however, only S ‐metolachlor at 0.28 kg ha −1 resulted in less than 20% injury to rice, comparable to microencapsulated (ME) acetochlor. While 0.28 kg ha −1 of S ‐metolachlor resulted in rice with similar tolerance to ME acetochlor, barnyardgrass control was less than 60%, which is not viable in rice.

Fluridone use in furrow-irrigated rice: Palmer amaranth control and crop response

Weed Technology · 2025-01-01

Abstract Rice cultivated under furrow irrigation faces weed management challenges due to the aerobic conditions that favor the emergence of terrestrial weeds such as Palmer amaranth. Fluridone was recently registered for use in rice production, offering an alternative site of action for Palmer amaranth control. Four site-years of field experiments were conducted in 2022 and 2023 in furrow-irrigated rice to assess Palmer amaranth control and crop tolerance to fluridone applied preemergence alone or with various postemergence treatments. The experiment was a randomized complete block design with a split-plot arrangement and four replications. The whole-plot factor was the postemergence treatment, while the subplot factor was fluridone applied preemergence at 0, 84, 168 (1× labeled rate), and 336 g ai ha −1 . Postemergence treatments included no herbicide, a single florpyrauxifen-benzyl application at 6 wk after rice emergence(WAE), and a weed-free control. The 2× rate of fluridone caused the greatest visual injury compared with the 0.5× rate across site-years at 2 and 5 WAE, ranging from 8% to 34%. The 1× and 2× rates of fluridone provided the greatest reduction in Palmer amaranth density 4 wk after treatment (WAT). However, the effect diminished or became less prominent by 8 WAT. Palmer amaranth density at rice harvest was reduced in most instances after a follow-up application of florpyrauxifen-benzyl, and seed production had diminished by ≥94% compared to its absence. Regardless of the fluoridone rate, rough rice grain yield was not affected under weed-free conditions. These findings suggest that integrating fluridone with a subsequent florpyrauxifen-benzyl application enhances Palmer amaranth management in furrow-irrigated rice compared to using fluridone alone. However, sequential applications are needed for successful Palmer amaranth control.

Effect of carrier volume and nozzle type on spray deposition within the canopy, disease control and yield in peanut

Crop Forage & Turfgrass Management · 2025-02-14 · 1 citations

Abstract Effective disease and pest management in peanut ( Arachis hypogea L.) requires adequate spray penetration within the canopy during pesticide applications. Field studies were conducted to assess spray deposition within the peanut canopy at three carrier volumes of 10, 15 and 20 gallons per acre (GPA), with each volume applied using three different nozzle types (extended range [XRC], air induction extended range [AIXR], and Turbo TeeJet Induction [TTI]). Spray deposition was assessed using water at various application timings (45, 60, 90, and 120 DAP) by placing water‐sensitive paper at upper, middle, and lower positions within the peanut canopy. Fungicide applications using different carrier volume and nozzle treatments were made at regular intervals throughout the season, and disease ratings along with peanut yield were recorded at harvest. The carrier volume of 20 GPA consistently provided the greatest deposition in the upper and middle canopy, followed by 15 and 10 GPA. The XRC nozzle exhibited the greatest deposition in the upper canopy, followed by the AIXR and TTI nozzles. Within the lower canopy, the effect of carrier volume and nozzle type on spray deposition varied among the application timings. For disease control, the lower carrier volume of 10 GPA and XRC nozzle showed an increased incidence of late leaf spot ( Nothopassalora personata ) and southern stem rot ( Sclerotium rolfsii Sacc.) in one of the study years. Carrier volume and nozzle type did not affect peanut yield during both years. Overall, the findings suggest that spray deposition within the peanut canopy is influenced by carrier volume and nozzle type; however, it does not necessarily lead to reduced peanut yield, especially in most fields with low to moderate disease pressure.

Rice cultivar tolerance to preemergence- and postemergence-applied fluridone

Weed Technology · 2025-01-01 · 1 citations

Abstract Fluridone was registered for use in rice production in 2023, offering a new herbicide site of action for growers. However, little information is available on the degree of rice tolerance to this herbicide. Field experiments conducted in 2022 and replicated in 2023 near Colt, AR, evaluated the tolerance of 12 rice cultivars to fluridone, applied preemergence or at the 3-leaf growth stage, in separate experiments. Each experiment consisted of one cultivar. Fluridone rates included 0, 168 (1 × label rate), and 336 (2 × label rate) g ai ha −1 in all experiments. Visible injury varied between years in all experiments, likely due to different environmental conditions. In 2022, injury following preemergence applications of fluridone was below 25% across cultivars. In contrast, in 2023, injury ≥30% occurred to five cultivars, with a maximum of 58% observed for the cultivar ‘DG263L’. In both years, only three cultivars exhibited injury ≥20% following fluridone applications at the 3-leaf stage. Fluridone negatively affected shoot density, groundcover, chlorophyll content, and days to 50% heading in most cultivars when applied preemergence. When fluridone was applied to 3-leaf rice, at least one of the variables evaluated was negatively affected in two and nine cultivars in 2022 and 2023, respectively. Grain yield reductions of at least 18% were observed from eight cultivars in 2022, and a grain yield decrease from 9% to 49% from eight cultivars occurred in 2023 in the preemergence experiments. Fluridone applied to rice at the 3-leaf stage did not cause a yield penalty to any cultivar in 2022, whereas in 2023, a yield loss occurred from eight cultivars. Yield loss from the DG263L cultivar occurred at the 1 × rate in both experiments, indicating that this cultivar appears to be sensitive to fluridone, regardless of the application timing. Based on these findings, fluridone tolerance is cultivar-dependent. Furthermore, preemergence applications of fluridone to rice should be avoided.

Soybean reproductive physiology as affected by sublethal rates of auxin mimic herbicides

Scientific Reports · 2025-08-04 · 1 citations

Auxin mimic herbicide off-target movement is a major environmental concern; it can affect crop yield, endangered species, and pollinator foraging sources. For the first time, the effects of sublethal rates of four auxin mimic herbicides (2,4-D, dicamba, florpyrauxifen-benzyl, and quinclorac) were evaluated to improves our understanding of how these herbicides negatively impact a pollinator nutritional source of pollinators. Dicamba and florpyrauxifen-benzyl applied at 1/100x of the labeled rate (5.60 g ae ha− 1 dicamba and 0.30 g ha− 1 florpyrauxifen-benzyl) reduced the total number of soybean reproductive organs (flowers and pods) by 31% and 27%, respectively, compared to the nontreated control (n = 373). Exposure to the same rates reduced pollen grains per anther by 25% and 18%, respectively, compared to the nontreated control (n = 338). The maximum reproductive per plant biomass accumulated was reduced by 30% from sublethal rates of dicamba and florpyrauxifen-benzyl applications at 1/100x compared to the nontreated control (23 g plant-1). An application of dicamba and florpyrauxifen-benzyl at 1/100x resulted in a 24% and 11% reduction in grain yield, respectively, compared to the nontreated control (3063 kg ha-1). While soybean reproductive organs, pollen grains, and yield were reduced from dicamba and florpyrauxifen-benzyl, 2,4-D and quinclorac had no impact on soybean physiological responses in this study. These results reinforce the idea that exposure to auxin mimic herbicides could reduce the quantity of pollen which could negatively affect pollinators’ foraging sources. Albeit, this relationship is highly dependent on the specific herbicide active ingredient and rate. This trend could have major implications for commercial bee keepers regarding the health of their bees near soybean fields that had drift damage. Proactive mitigation strategies are required when using auxin mimic herbicides to prevent off-target movement and subsequent negative consequences for pollinator foraging sources.

Grass weed control and rice response with tetflupyrolimet-containing programs

Weed Technology · 2025-01-01 · 2 citations

Abstract Tetflupyrolimet is the first herbicide with a novel site of action (SOA) labeled PRE and early POST for use in agronomic crops to be labeled in the last three decades. Direct-seeded paddy rice field experiments were conducted near Stuttgart, AR, on a silt loam soil and near Keiser, AR, on a clay soil to evaluate tetflupyrolimet-containing herbicide programs in comparison to commercial standards in conventional, imidazolinone-resistant, and quizalofop-resistant rice systems. Additionally, a furrow-irrigated rice experiment was conducted near Colt, AR, and Keiser to ensure weed control with clomazone and tetflupyrolimet mixtures compared to commercial standards. Twelve commonly planted rice cultivars were also evaluated in response to a single PRE or POST (2- to 3-leaf rice) application of tetflupyrolimet at 200 or 400 g ai ha −1 in a paddy rice system near Colt. When averaged over soil texture and site-year, all herbicide programs provided ≥98% barnyardgrass control at 56 d after (DA) the last application. Visible rice injury varied for each rice system. Still, injury rarely differed among herbicide programs, except at a single evaluation timing in the conventional (7 DA, 3- to 4-leaf applications) and quizalofop-resistant (preflood) systems. All 12 rice cultivars displayed high tolerance to a single PRE or POST application of tetflupyrolimet at 200 or 400 g ai ha −1 . No visible injury, stand loss, or negative impact on rice maturity or reduced grain yield was observed for any cultivar. Tetflupyrolimet will be an effective alternative SOA in a program approach for barnyardgrass while maintaining excellent rice crop safety.