ABSTRACT Vulpia myuros has recently emerged as a problematic grass weed in European arable systems, particularly under reduced tillage. An online survey of 471 farmers across Western Europe was used to assess the distribution of V. myuros , associated farming practices, and perceived management challenges. Overall, 79% of respondents were aware of the species, and 65% reported its presence on their farms, with infestations most often described as relatively recent (< 5 years). More than one‐third of affected farmers (37%) indicated that V. myuros had become more problematic in the past 3 years, and 20% reported infestations affecting more than 25% of the field area. Vulpia myuros was most reported in winter crops (71%) and more frequently under reduced tillage than under inversion tillage. No difference in soil type was observed between farms with and without V. myuros . Most respondents used herbicides as the main weed control, and 65% of farmers with V. myuros considered the weed difficult to control. Perceived difficulty of control was positively associated with the percentage of the field area infested but showed no clear relationship with tillage practice or the length of time the species had been present on the farm. Differences in the age and extent of infestations were observed between France and the United Kingdom, with older and more severe infestations observed in France. Overall, these results identify V. myuros as an emerging and increasingly challenging weed in European arable systems, highlighting the need for earlier recognition and more proactive, integrated management strategies.
ABSTRACT Understanding how weed diversity influences crop productivity is essential for developing resilient and biodiversity‐supportive agricultural systems. We conducted an integrative review combining bibliometric analysis, systematic review and meta‐analysis to synthesise evidence on the relationship between weed community diversity and crop performance. Among 277 relevant publications, only a small subset assessed diversity–yield relationships, revealing a substantial gap between studies documenting weed diversity and those quantifying its agronomic implications. Research efforts were geographically concentrated in Europe and North America and dominated by cereal‐based systems. Qualitative synthesis showed highly variable outcomes, with weed diversity exerting positive, negative, or neutral effects on crop productivity. Meta‐analysis of 16 eligible studies (57 effect sizes) indicated that the overall effect of weed diversity on crop yield was neutral. Moderator analysis revealed that experimental design strongly mediated effect direction, with studies employing weed‐free controls more likely to report positive associations. Evenness and functional‐diversity based metrics were more consistently associated with positive yield responses, whereas species richness produced mixed results, highlighting the importance of community structure and trait diversity. Many negative associations likely reflected management‐driven covariation, where intensive practices simultaneously reduced weed diversity and increased yield, rather than ecological impacts. Our findings underscore the need for purposefully designed experiments that integrate functional, abundance‐based and trait‐oriented metrics to clarify mechanisms linking weed diversity with crop performance. Such insights are essential for advancing ecologically informed weed management that balances crop productivity with biodiversity conservation.
ABSTRACT Site‐specific weed management (SSWM) has long been promoted as a promising strategy to reduce herbicide use by adapting weed control to the spatial distribution of weeds. Despite decades of research and technological progress, adoption in commercial farming remains limited. This study investigates whether this gap reflects knowledge gaps within the scientific literature and, more prominently, a mismatch between research priorities and practical needs. A systematic literature search combined with bibliometric analyses was conducted using articles indexed in the Web of Science database. Bibliographic coupling and keyword co‐occurrence analyses were applied to map the structure of the SSWM research field. A total of 563 articles on SSWM were identified through the literature search. Most publications focus on weed detection, particularly recent studies using deep learning and machine vision. In contrast, only 40 papers address site‐specific herbicide application as a complete workflow integrating weed detection, decision‐making and site‐specific herbicide application under realistic field conditions. The bibliometric analyses reveal disciplinary fragmentation and limited cross‐disciplinary integration. Furthermore, the limited number of integrated SSWM studies, combined with a pronounced lack of on‐farm studies and farmer interactions, indicates a significant research–practice gap. Without stronger engagement with on‐farm realities and better integration across disciplines, weed research risks becoming increasingly invisible to farmers and policymakers, thereby diminishing its societal impact despite its potential contribution to sustainable agriculture.
ABSTRACT Weed management in cover crop‐based, organic rotational no‐till (CCORNT) production is achieved via in situ cover crop mulch. However, ineffective cover crop termination impedes this sustainable practise. Cereal rye ( Secale cereale ; CR) is terminated via roll‐crimping, which crushes the vascular tissue along the stem. Previous studies suggested optimal growth stages (GS) to maximise termination efficacy (TE), but the effect of the distribution of individual morphological and ontogenetic traits on roller‐crimper TE has not been described. In a field study in Pennsylvania, USA, we tested the effects of (1) seeding density on CR trait variation, and (2) trait variation effect on TE. We managed CR populations with two factors, seeding rate (150, 300, 600, 900 seeds m −2 ) and sowing arrangement (row, grid). We measured the slenderness and GS of individual tillers and assessed inequality in trait distributions with Gini coefficients. We also quantified stem density and total biomass. Following roll‐crimping, we assessed TE (1 − (surviving stems/initial stem density)) and CR seed production. Cereal rye seeding rate affected all traits assessed. Slenderness and GS were positively correlated with TE, but structural equation models did not support the hypothesis that these traits mediated the positive relationship between seeding rate and TE. In contrast, stem density fully mediated the relationship between seeding rate and TE and was the best predictor of TE. Sowing arrangement did not affect cereal rye traits or TE. Our research suggests increasing seeding rate affected CR trait distributions and increased stem density led to improved roll‐crimping efficacy. Ultimately, increasing seeding rates may minimise the risks in adopting CCORNT production practises.
ABSTRACT Unmanned aerial vehicles (UAVs) are increasingly considered a promising alternative to conventional ground‐based herbicide application in rice production systems; however, their effectiveness depends strongly on optimizing operational parameters that influence spray deposition, biological efficacy, and crop response. Field experiments were conducted during the 2023–2025 growing seasons in the Marmara and Black Sea regions of Turkey to (i) identify optimal UAV application parameters for effective weed control and (ii) compare the performance of optimized UAV spraying with that of conventional ground‐based application in rice. A factorial experimental design was used to evaluate the effects of UAV flight height (1.5, 3, 4, and 5 m), flight speed (4.4, 5.5, and 6.6 m s −1 ), and spray volume (20, 30, and 40 L ha −1 ) on spray area coverage, weed control efficacy, weed dry weight, crop phytotoxicity, tiller number, and grain yield. Spray area coverage was significantly influenced by all UAV operational parameters and their interactions; however, maximum coverage at the lowest flight height did not result in improved weed control. Weed control efficacy and weed dry weight reduction were optimized at a flight height of 4 m, particularly at a flight speed of 5.5 m s −1 and spray volumes of 30–40 L ha −1 . Grain yield was significantly affected by UAV parameters and region, while year effects were not significant, indicating the robustness of the optimized application strategy across seasons. Using the optimal UAV settings (4 m flight height, 5.5 m s −1 speed, and 30 L ha −1 spray volume), weed control efficacy exceeded 90% and weed dry weight was reduced to levels comparable with those achieved by conventional application at 300 L ha −1 , despite significantly lower spray area coverage. Overall, the results demonstrate that properly optimized UAV‐based herbicide application can provide effective, stable, and integrated weed control in rice while substantially reducing spray volume and improving application efficiency.
ABSTRACT Sclerotium rolfsii is a soil‐borne fungal pathogen with potential as a mycoherbicide. Considering its spreading capability through mycelium, this study aimed to investigate the spatiotemporal spread of S. rolfsii on herbicide‐resistant (HR) Monochoria vaginalis , a problematic weed in paddy fields. In a controlled environment, S. rolfsii exhibited a circular spreading pattern, which was well described by the Gompertz model. At 1 day after treatment (DAT), germination initiated, followed by mycelium formation at 3 DAT. The infection expanded in a circular pattern at a rate of 118.72 cm 2 /day, with the infection radius increasing by 1.59 cm/day. It was estimated that 10.9 days were required to control a 200 cm 2 area and 13.3 days for a 600 cm 2 area. Additionally, the complete infection of HR M. vaginalis occurred at approximately 2.2 days after mycelial contact, indicating the time for herbicidal action after mycelium expansion. Sclerotium rolfsii demonstrated a high mycelial spreading capacity and a prolonged persistence, highlighting its potential as an effective mycoherbicide. These findings also offer valuable insights for determining optimal application methods of S. rolfsii to control HR M. vaginalis . Further research will focus on how its spread and herbicidal efficacy vary under paddy field conditions.
ABSTRACT Resistance to 2,4‐D has evolved in Conyza sumatrensis , with some resistant accessions expressing rapid response (RR) resistance, characterised by rapid necrosis followed by regrowth. This study evaluated biochemical and physiological changes in two RR‐resistant accessions after treatment with 2,4‐D and other auxinic herbicides. RR symptoms occurred only with 2,4‐D, while clopyralid, triclopyr, florpyrauxifen‐benzyl and dicamba caused complete mortality. In RR‐resistant accessions, exposure to 2,4‐D resulted in a threefold increase in superoxide dismutase activity, a 45% decline in PSII efficiency, reductions of up to 95% in photosynthesis and 40%–60% reductions in transpiration compared to susceptible plants. Necrosis was enhanced by light and the availability of cytokinin and sucrose, resulting in a reduction in green leaf area. Foliar uptake of 2,4‐D was approximately 11% greater in RR‐resistant accessions compared to the susceptible one, but translocation was approximately half of that in the susceptible accessions. These results indicate that RR resistance in C. sumatrensis involves reduced translocation, enhanced antioxidant capacity and an energy‐linked process triggered specifically by 2,4‐D. From a practical perspective, our findings confirm that RR‐resistant accessions do not have cross‐resistance to other auxinic herbicides, supporting chemical rotation options and reinforcing the need for integrated management strategies to limit the spread of this resistance phenotype.
Invasive alien species (IAS) are considered key drivers of population decline and extinction on islands. In Fiji and elsewhere in the Pacific, the long history of fascination with horticultural novelty has largely contributed to biological invasions. African tulip ( Spathodea campanulata P. Beauv.) was introduced as an ornamental tree in the early part of the 20th century. Ever since, it has escaped cultivation and widely naturalised, invading abandoned agricultural fields, degraded areas, and human‐disturbed forests. We review the mechanisms driving S. campanulata invasions in the region, impacts, management strategies, and the way forward for the Pacific. Despite scientific evidence, polarised perceptions have undermined management actions. This incongruity calls for efforts directed towards integrated management, co‐designing strategies, raising public awareness, rapid response teams for high conservation value forests, leveraging regional initiatives, and legislation.
Cirsium arvense L. (Canada thistle) is a perennial weed with an extensive root system and prolific vegetative propagation through adventitious root buds, making long-term management challenging. Florpyrauxifen-benzyl, a novel synthetic auxin herbicide, has shown potential for controlling broadleaf weeds, but its effects on C. arvense root growth and regeneration are not documented. Greenhouse studies evaluated florpyrauxifen-benzyl at 9-38 g ai ha-1, applied as single or sequential treatments at the rosette and bolting stages, measuring control, root biomass reduction, and root bud regeneration. A second greenhouse study compared florpyrauxifen-benzyl (29 g ha-1) with glyphosate, clopyralid, 2,4-D, glufosinate, flazasulfuron, carfentrazone, and selected mixtures. Field studies evaluated florpyrauxifen-benzyl programs alone or in combination with mowing across three sites. In the greenhouse, florpyrauxifen-benzyl provided 86%-94% shoot control, reduced root biomass by >= 97% at the rosette stage and by >= 80% at the bolting stage, and lowered root bud regeneration to <= 14% of root segments, an effect comparable to that of glyphosate and clopyralid. In the field, sequential applications or mowing followed by florpyrauxifen-benzyl significantly improved control (73%-79%) compared to a single spring application (69%) or single summer application (30%). Mixtures of florpyrauxifen-benzyl with glufosinate or flazasulfuron did not improve control of C. arvense. Results indicate that florpyrauxifen-benzyl effectively controls C. arvense through reductions in root biomass and inhibition of vegetative regeneration, with performance comparable to industry standards. These results support its use in perennial cropping systems, where it can be integrated with practices such as mowing or sequential applications to improve season-long control and reduce flowering and seed production.
Crassula helmsii (Kirk) Cockayne is an invasive aquatic species increasingly colonising European freshwaters and wetlands. Despite its rapid spread, the mechanisms underlying its establishment remain poorly understood. This study experimentally assessed the effects of propagule pressure, native plant competition, temperature and soil moisture on the colonisation and regeneration ability of C. helmsii. Three complementary experiments were conducted under greenhouse, outdoor mesocosms and growth chambers, respectively. Establishment success and growth performance were measured (i) across varying propagule densities (one or three propagules), in the presence or absence of native grasses (Agrostis stolonifera and Phalaris arundinacea), (ii) under a gradient of soil moisture (dry to wet) and (iii) under two temperatures (18 degrees C and 23.5 degrees C). Contrary to expectations, propagule pressure did not enhance establishment or regeneration ability of C. helmsii, suggesting that colonisation success is not density-dependent. In some cases, higher propagule densities even reduced individual establishment, possibly due to intraspecific interactions. Neighbour grasses facilitated early establishment-likely through microclimatic buffering-but later limited C. helmsii growth through competition for resources, demonstrating a shift from facilitation to inhibition. Soil moisture strongly influenced regeneration ability, with desiccation followed by rehydration triggering delayed regrowth. In contrast, variation in temperature had negligible effects on plant performance. These results highlight the plasticity of C. helmsii and the importance of both biotic resistance and abiotic factors in regulating its invasion potential. Management strategies should integrate the role of native vegetation and moisture regimes to prevent colonisation and minimise re-establishment following control efforts.
One key factor in the success of invasive alien species is their frequent competitive superiority over native plants. The interspecific competitive distance between invasive and native plants may vary across different communities. This study aimed to evaluate the functional differences between Solidago canadensis L. and native plants, plant taxonomic diversity, the invasion intensity of S. canadensis and the community invasibility under different interspecific competitive distances between S. canadensis and native plants. This study conducted a comparative field investigation in Zhenjiang, China. S. canadensis and native plants exhibited functionally convergence under the invasion scenario with close interspecific competitive distance, whereas they diverged functionally under the invasion scenario with distant interspecific competitive distance. The invasion intensity of S. canadensis and the community invasibility were greater under the invasion scenario with distant interspecific competitive distance than those under the invasion scenario with close interspecific competitive distance. S. canadensis declined the species number, diversity and richness of plants only under the invasion scenario with distant interspecific competitive distance. Key drivers of the invasion intensity of S. canadensis included the sunlight capture capacity and the community-weighted mean trait values, especially under the invasion scenario with distant interspecific competitive distance. Therefore, the interspecific competitive distance between S. canadensis and native plants may be a critical factor affecting the functional differences between S. canadensis and native plants, the effects of S. canadensis on plant taxonomic diversity, the invasion intensity of S. canadensis and the community invasibility.
Convolvulus arvensis L. is a noxious weed with high ecological and phenotypic plasticity that can thrive, adapt and invade under various environmental conditions. It was hypothesized that the infestation success of C. arvensis is linked with its microstructural and physiological variation, allowing it to infest across a range of crops. C. arvensis specimens were collected from various cultivated crops across the Punjab province of Pakistan. Sixteen crop types were selected, with all fields having received neither pre-emergence nor post-emergence herbicide applications. The soil analysis from different sites showed significant variability in physicochemical characteristics. Tallest C. arvensis plants were in the Hordeum vulgare field, a strategy to transcend the host crop for light. Regarding root and stem anatomical traits, the Medicago sativa population had the thickest epidermis, and largest cortical cells reflecting an adaptive response to arid conditions. Populations such as H. vulgare, Cicer arietinum, Saccharum officinarum, and Vigna radiata had massive sclerification of the vascular region, to withstand environmental stresses. The foliar anatomical features also revealed significant inter-population variability. In the Oryza sativa, large aerenchyma cavities and small stomata was an adaptation for saline or arid environment. Anatomical traits, that is, aerenchyma development, vascular differentiation, and epidermal modifications were key indicators for its adaptation and to thrive in different habitats. These features reflect its significant ecological adaptability and phenotypic plasticity across diverse crops and environmental conditions.
Assessing which weed species are likely to expand under climate change is essential for proactive management. While climate-driven range expansions of many weed species have been documented globally, projections for their future spread in Central Europe remain limited and poorly understood. We used ensemble species distribution models for 23 weed species that are currently emerging in Central Europe to evaluate their climatically suitable areas at present and future time periods (2041-2060, 2061-2080 and, 2081-2100) under four different future climate change scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5). The climatic suitability of our study area is predicted to increase for all species in the two earlier time periods and under moderate climate change conditions. However, climate change is likely to reduce the potentially suitable area in later time periods and under more severe scenarios. The climatically suitable area is expected to decline or remain stable for 14 of the modelled species, of which two thirds show a decline by 2100, regardless of the climatic trajectory. Furthermore, hotspots of climatic suitability, where multiple emerging weeds overlap are shifting northwest under the two more moderate climate change scenarios, whereas under the two severe climate change scenarios, hotspots are likely to shrink by 2100. Additionally, we found that most of the modelled species whose suitable area increases are C4 plant species, while those with decreasing suitability are predominantly C3 plants. Our findings underscore the importance of monitoring and proactive management strategies to mitigate the impacts of emerging weeds, particularly those better adapted to future climatic conditions.
Sustainable alternatives to synthetic herbicides are increasingly needed in legume cropping systems, driven by the growing demand for organically produced grain legumes (where synthetic herbicides are prohibited) and the very limited number of chemical herbicides registered for conventional grain legume production. This study evaluated the herbicidal potential of ethanolic plant extracts for controlling common chicory (Cichorium intybus L.) in chickpea (Cicer arietinum L.) crops during the 2021-2022 and 2022-2023 seasons in Kermanshah, Iran. Foliar treatments included ethanolic extracts of chamomile (Anthemis odontostephana Boiss.), tumble thistle (Gundelia tournefortii L.), and peanut (Arachis hypogaea L.) shell, pelargonic acid, Challenge herbicide (aclonifen), and a distilled water control. GC-MS analysis was performed only on the chamomile extract, which exhibited the highest herbicidal efficacy, to identify key bioactive compounds responsible for its superior weed suppression. Chamomile extract provided the strongest weed control, increasing chickpea biomass by up to 55.53% and reducing chicory biomass by up to 73.81% relative to the control 2 weeks after application. It achieved the highest weed control ability (91%-94%) and caused the greatest reductions in chicory chlorophyll content (down to 16.13 SPAD units vs. 50.6 in control) and stomatal conductance (64%-75% reductions). GC-MS of the chamomile volatile fraction identified 21 compounds, with myrtenyl acetate, decanoic acid, spathulenol, and caryophyllene oxide predominant. These findings demonstrate that chamomile ethanolic extract, rich in terpenoids such as myrtenyl acetate, shows strong potential as a natural bioherbicide for sustainable management of common chicory in chickpea. Given the widespread occurrence of C. intybus as a problematic weed in various grain legume crops worldwide, this extract may warrant further evaluation in other legume cropping systems.
ABSTRACT Calotropis procera and C. gigantea are emerging as globally invasive plants that can significantly alter ecosystems in areas where they have escaped from attended cultivation. Without effective management, these species can form dense monospecific stands, resulting in severe economic, environmental and social impacts. Current control measures for these species are often limited in effectiveness, especially when applied as single‐use approaches. To address this issue, this review synthesises key biological and ecological traits, current and potential invasion dynamics and management options available for C. procera and C. gigantea . Although more detailed investigation is required in some areas, it appears that an integrated approach is emerging as a possible option. Such an approach should consider (i) early detection and preventative strategies, including creating and maintaining competitive pastures and reducing soil disturbance, (ii) biological control, with the potential development and release of host‐specific insects and plant pathogens, (iii) chemical control with diverse modes of action, (iv) physical control including manual removal of all plant propagules from the soil and (v) ecological burn programs to remove the aboveground biomass followed by chemical or physical interventions. It is anticipated that the implementation of these strategies is likely to significantly mitigate the impacts posed by established C. procera and C. gigantea stands, while also addressing and removing newly emerging individuals before they develop robust populations.
Bottle gourd (Lagenaria siceraria) production is generally constrained by complex weed communities dominated by purple nutsedge (Cyperus rotundus). While halosulfuron-methyl is widely used for sedge control, the quantitative understanding of how weed community dynamics influence crop yield and rotational safety in vegetable systems remains limited. A two-year field study was conducted at the Punjab Agricultural University Regional Research Station, Abohar, to compare POST-applied halosulfuron (52.5 and 67.5 g ai ha-1) with PRE-applied pendimethalin (750 g ai ha-1), a hand-weeded standard, a weed-free, and untreated control in randomised block design. Halosulfuron at 67.5 g ha-1 reduced total weed biomass by 80% compared with the untreated control and was more effective than pendimethalin. Total weed biomass explained 88% (35 days after bottle gourd sowing; DAS) and 89% (55 DAS) of yield variation (-38 kg fruit per kg weed biomass; R 2 >= 0.88), and C. rotundus biomass alone accounted for 80%-84% of the variance in yield. Regression analysis further identified biomass thresholds associated with a 10% yield loss, highlighting the crop's high sensitivity to early-season weed interference. Application of halosulfuron at 67.5 g ai ha-1 and hand weeding, both treatments produced 46-47 t ha-1 bottle gourd yield, about 89% of the weed-free. To evaluate rotational safety for mustard, field emergence, early biomass and seed yield were assessed. Equivalence testing indicated that halosulfuron at 52.5 g ai ha-1 and pendimethalin were statistically equivalent to hand weeding for mustard emergence and early biomass. In contrast, the halosulfuron 67.5 g ha-1 did not meet the equivalence criteria, with large effect for emergence and seed yield, although ANOVA detected non-significant treatment effect on mustard seed yield. Therefore, the higher halosufuron rate should be considered effective for sedge suppression in bottle gourd but require cautious approach for succeeding mustard crop.
Accurate species identification is essential for effective weed management. However, conventional morphology-based approaches are limited by expertise shortages and ambiguous diagnostic characters. This study evaluated the performance of three web-based image identification platforms (iNaturalist, PlantNet, Google Lens) and DNA barcoding (rbcL, matK) against morphological identification for 39 random mature weed plants from Jelebu, Malaysia. Preliminary morphological identification resolved 71.8% of the plants to the species level. PlantNet, iNaturalist, and Google Lens identified 92.3%, 84.6%, and 84.6% of the plants to the species level, respectively. All three platforms produced concordant identifications for 71.8% of plants and confirmed the preliminary identifications in 61.5% of cases. By contrast, rbcL yielded species-level matches for all plants, whereas matK failed to resolve two plants to the species level. Marker discordance between rbcL and matK was observed in 10 plants. Comparison between rbcL and identification applications showed only 41.0% matches across all platforms, whereas 46.2% were wholly discordant. Notable reassignments by barcodes illustrate visually plausible but incorrect morphological identifications. Our results indicate that image identification platforms offer rapid, user-friendly tools but can produce substantial misidentifications. Molecular barcodes provide higher objectivity but have limitations like accessibility, marker discordance and database issues. We recommend an integrated workflow between image-based platforms, targeted barcoding for low-confidence cases, and expert validation to improve identification accuracy for operational weed management and broader biodiversity applications.
The presence of Conyza spp. biotypes in irrigated rice fields suggests potential adaptive mechanisms for flood tolerance, prompting this study to evaluate their response to flooding. A total of 37 Conyza biotypes were collected in southern Brazil and grouped into three geographic categories. When the biotypes reached 15 cm in height, a 4 cm water layer was applied for 15 days. The variables evaluated were visual injury, plant height, leaf chlorophyll content and root and shoot dry mass at the end of the experiments. Additionally, the expressions of ALAT2, GLB1, PDC1, SUB1A and ERF2 genes were assessed in three selected biotypes (susceptible, Tolerant 1 and Tolerant 2), in meristematic and mature tissues, 4 and 10 days after flooding. The results indicate variation in the responses with no clear trend across geographic groups. The biotypes SAN, SAU, TPA, FDS and SMA4 exhibited injury scores >= 7, indicating null tolerance to temporary flooding stress. Conversely, JCS, RES1, SMA1, BRO, CSL, ITQ and SMA2 demonstrated potential to thrive in temporary flooded conditions. Gene expression varied by assessment moment and tissue type. The expression of the ALAT2, PDC1 and GLB1 (energy metabolism) genes increased, particularly in biotype Tolerant 1. The ERF2 (ethylene response factor) gene showed increased expression in susceptible and Tolerant 2 biotypes, while the SUB1A (quiescence strategy) gene showed increased expression in all three biotypes. It can be concluded that there is variability in the response of Conyza spp. biotypes to flooding conditions, with no relationship found between gene expression and tolerance.
Early detection of herbicide-induced stress is essential for optimising weed control, improving crop safety and advancing precision agriculture practices. While non-destructive imaging technologies offer great potential for rapid stress diagnosis, direct comparisons of their performance across species, herbicides and application rates remain scarce. This study systematically compared three high-throughput imaging methods: chlorophyll fluorescence imaging, multispectral imaging and 3D multispectral scanning, for their ability to detect and classify early physiological and morphological responses to bentazone (HRAC 6) and glyphosate (HRAC 9) in a weed (velvetleaf, Abutilon theophrasti) and a crop species (common bean, Phaseolus vulgaris). Plants were imaged daily, immediately before treatment and for five consecutive days after herbicide application. Chlorophyll fluorescence parameters, particularly NPQ, q P and F s ', emerged as the earliest and most sensitive indicators, detecting stress within 24 h of treatment. Stepwise discriminant analysis revealed that intermediate time points (48-72 h after application) achieved the highest classification accuracies, reaching up to 100%, with chlorophyll fluorescence as the dominant trait for selection. Multispectral traits, such as reflection in red and far red, and saturation, together with morphological traits like total leaf area and leaf inclination, provided complementary information and enhanced discrimination accuracy among herbicides. These findings highlight the superiority of chlorophyll fluorescence imaging for detecting early herbicide stress, while demonstrating the added value of integrating spectral and morphological traits. The results support the development of multi-sensor phenotyping pipelines for rapid, accurate and field-adaptable diagnostics in both weed and crop management.
Tillage disturbs predator communities and can alter post-dispersal weed seed removal in arable systems. Weed seed predation represents a low-input pathway that may contribute to reductions in seed return, yet variation in predation rates across tillage intensity, seasons and weed species remains incompletely understood in UK cropping systems. Here, we quantified weekly predator-attributable seed losses using seed cards in six fields managed under contrasting tillage systems (three no-till and three conventional) over 2 years, focusing on Alopecurus myosuroides, Bromus secalinus and Avena fatua. Predation was consistently greater in no-till, with weekly removals averaging 76%-79% compared with 46%-52% in conventional tillage, although rates varied markedly among seasons. Losses were consistently highest in spring, while seed losses in autumn and summer varied from year to year, alternating in rank. Inter-annual differences were slight and did not alter the direction or magnitude of the tillage contrast. Species differences were moderate: B. secalinus generally showed lower seed removal, while A. fatua and A. myosuroides were similar and slightly higher. These findings demonstrate that reduced soil disturbance is associated with consistently greater surface seed removal by predators, which represents an important complementary process within integrated weed management. Practices that maintain surface residues and predator habitat may therefore enhance the contribution of biological seed removal in systems that rely on reduced tillage, including those often described as regenerative.
