Search Results (603)

Weed management remains a critical challenge in the U.S. container ornamental production industry, where weeds not only compete with crops for limited resources but also harbor pests and pathogens, thereby diminishing plant quality and marketability. The paper explores the economic impact of weed infestations, herbicide resistance development, and the limited availability of selective herbicides for ornamental crops in the United States. This review synthesizes current chemical weed control tactics, focusing not only on both preemergence and postemergence herbicides commonly used in ornamental nurseries, but also organic alternatives and integrated weed management (IWM) approaches as complementary strategies by evaluating their effectiveness, crop safety, and usage. There is a critical need for research in the areas of alternative chemical options such as insecticides, miticides (e.g., Zerotol and Tetra Curb Max), and organic products for liverwort control in greenhouses. Although essential oils and plant-based extracts show some potential, their effectiveness and practical use remain largely unexplored. Full article

Dodders (Cuscuta spp.; Convolvulaceae) are parasitic weeds that pose major challenges to agriculture due to their ability to infect a wide range of host plants, extract nutrients, and transmit pathogens. Their control is especially challenging because of the seed longevity, resistance to herbicides, and the capacity for vegetative regeneration. Mechanical methods such as hand-pulling or mowing are labour-intensive and often ineffective for large infestations. Chemical control is limited, as systemic herbicides often affect the host species equally, or even worse than the parasite. Current research is exploring biological control methods, including allelopathic compounds, host-specific fungal pathogens, and epiparasitic insects, though these methods remain largely experimental. An integrated approach that combines prevention, targeted mechanical removal, and biological methods offers the most promising path for long-term management. Continued research is essential to develop effective, sustainable control strategies while exploring possible beneficial uses of these complex parasitic plants. The present review aims to thoroughly summarise the existing literature, emphasising the most recent advances and discussing future perspectives. Full article

Asia minor bluegrass (Polypogon fugax), a widespread Poaceae weed, exhibits broad tolerance to abiotic stresses. Validated reference genes (RGs) for reliable RT-qPCR normalization in this ecologically and agriculturally significant species remain unidentified. This study identified eight candidate RGs using transcriptome data from seedling tissues. We assessed the expression stability of these eight RGs across various abiotic stresses and developmental stages using Delta Ct, BestKeeper, geNorm, and NormFinder algorithms. A comprehensive stability ranking was generated using RefFinder, with validation performed using the target genes COR413 and P5CS. Results identified EIF4A and TUB as the optimal RG combination for normalizing gene expression during heat stress, cold stress, and growth stages. EIF4A and ACT were most stable under drought stress, EIF4A and 28S under salt stress, and EIF4A and EF-1 under cadmium (Cd) stress. Furthermore, EIF4A and UBQ demonstrated optimal stability under herbicide stress. Additionally, application of validated RGs revealed higher acetyl-CoA carboxylase gene (ACCase) expression in one herbicide-resistant population, suggesting target-site gene overexpression contributes to resistance. This work presents the first systematic evaluation of RGs in P. fugax. The identified stable RGs provide essential tools for future gene expression studies on growth and abiotic stress responses in this species, facilitating deeper insights into the molecular basis of its weediness and adaptability. Full article

False cleavers (Galium spurium L.) is a broadleaf weed species that affects wheat productivity because of its strong competition for resources. It has developed resistance to acetolactate synthase (ALS) inhibitors, such as sulfonylureas and triazolopyrimidines, which are herbicides widely used in durum wheat. Integrated weed management programs can contribute to the control of this species and delay the evolution of herbicide resistance. Thus, a two-year field experiment was conducted to evaluate the effects of sowing time, variety, and herbicides on crop yield, density, and dry weight of a false cleavers population with resistance to ALS inhibitors. In both growing seasons, a split-split-plot design was used with three replicates. The sowing date was chosen as the main plot factor, durum wheat varieties as the subplot factor, and herbicides as the sub-subplot factor. The herbicide treatments were: (1) metsulfuron-methyl/bensulfuron-methyl (4/50 g a.i. ha⁻¹), (2) aminopyralid/florasulam (9.9/4.95 g a.i. ha⁻¹), (3) pyroxsulam and florasulam/2,4-D (18.75 + 4.725/225 g a.i. ha⁻¹), (4) 2,4-D/bromoxynil (633.15/601.2 g a.i. ha⁻¹), non-treated control, and hand-weeded control for the first season, while in the second season one more herbicide treatment (halauxifen-methyl/florasulam, 5.6/5.15 g a.i. ha⁻¹) was added. Herbicide application was performed on 10 March 2021 and 28 March 2022, when the crop was at the end of tillering and the beginning of stem elongation. The results showed that the density of false cleavers was not affected by the variety or sowing time. However, its dry weight was 17.3–23.4% higher in early sowing (16 November in 2020 and 8 November 2021) than in late sowing (24 December 2020 and 2 December 2021). Among the herbicides tested, 2,4-D/bromoxynil and halauxifen-methyl/florasulam effectively controlled false cleavers, showing greater efficacy in late sowing (>88%), which ultimately led to a higher yield. In conclusion, our two-year findings demonstrate that delayed sowing as part of an integrated weed management strategy can contribute to controlling resistant populations of false cleavers to ALS-inhibiting herbicides without affecting the quantity and quality of durum wheat yield in areas with a Mediterranean climate. Full article

Common ragweed (Ambrosia artemisiifolia L.) has been identified as one of the most harmful invasive weed species in Europe due to its allergenic pollen and competitive growth in diverse habitats. In the first part of this review [Common Ragweed—Ambrosia artemisiifolia L.: A Review with Special Regards to the Latest Results in Biology and Ecology], its biological characteristics and ecological behavior were described in detail. In the current paper, control strategies are summarized, focusing on integrated weed management adapted to the specific habitat where the species causes damage—arable land, semi-natural vegetation, urban areas, or along linear infrastructures. A range of management methods is reviewed, including agrotechnical, mechanical, physical, thermal, biological, and chemical approaches. Particular attention is given to the spread of herbicide resistance and the need for diversified, habitat-specific interventions. Among biological control options, the potential of Ophraella communa LeSage, a leaf beetle native to North America, is highlighted. Furthermore, innovative technologies such as UAV-assisted weed mapping, site-specific herbicide application, and autonomous weeding robots are discussed as environmentally sustainable tools. The role of legal regulations and pollen monitoring networks—particularly those implemented in Hungary—is also emphasized. By combining traditional and advanced methods within a coordinated framework, effective and ecologically sound ragweed control can be achieved. Full article

Goosegrass (Eleusine indica) is a major weed in Brazilian soybean, corn, and cotton systems, infesting over 60% of grain-producing areas and potentially reducing yields by more than 50%. Its competitiveness is due to its rapid emergence, fast tillering, C4 metabolism, and adaptability to various environmental conditions. A critical challenge relates to its widespread resistance to multiple herbicide modes of action, notably glyphosate and acetyl-CoA carboxylate (ACCase) inhibitors. Resistance mechanisms include 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) target-site mutations, gene amplification, reduced translocation, glyphosate detoxification, and mainly ACCase target-site mutations. This literature review summarizes the current knowledge on herbicide resistance in goosegrass and its management in Brazil, with an emphasis on integrating chemical and non-chemical strategies. Mechanical and physical controls are effective in early or local infestations but must be combined with chemical methods for lasting control. Herbicides applied post-emergence of weeds, especially systemic ACCase inhibitors and glyphosate, remain important tools, although widespread resistance limits their effectiveness. Sequential applications and mixtures with contact herbicides such as glufosinate and protoporphyrinogen oxidase (PPO) inhibitors can improve control. Pre-emergence herbicides are effective when used before or immediately after planting, with adequate soil moisture being essential for their activation and effectiveness. Given the complexity of resistance mechanisms, chemical control alone is not enough. Integrated weed management programs, combining diverse herbicides, sequential treatments, and local resistance monitoring, are essential for sustainable goosegrass management. Full article

Soybean production in Thailand faces significant challenges from malignant weed competition, potentially reducing yields by up to 37% and incurring annual economic losses of approximately USD 3.8 billion. Pre-emergence herbicides are critical for integrated weed management, but their efficacy varies depending on local conditions and soybean varieties. This study evaluates the performance of three pre-emergence herbicides, pendimethalin (1875 g a.i. ha⁻¹), s-metolachlor (900 g a.i. ha⁻¹), and flumioxazin (125 g a.i. ha⁻¹), on weed control efficiency (WCE), soybean growth, phytotoxicity, and yield in Northeast Thailand using a randomised complete block design with two varieties (CM60 and Morkhor60) across rainy (2023) and dry (2024/2025) seasons. Herbicide performance varied seasonally: s-metolachlor showed optimal rainy season results (61.54% weed control efficiency at 63 days after herbicide application (DAA), with a yield of 1036 kg ha⁻¹), while flumioxazin excelled in dry conditions (64.32% WCE, <4% phytotoxicity, and 1243 kg ha⁻¹ yield). Pendimethalin performed poorly under wet conditions but improved in drier weather. Among five dominant weed species, Cyperus rotundus proved the most resilient. CM60 demonstrated superior herbicide tolerance and yield stability, particularly under rainy conditions. These results emphasise that season-specific herbicide selection and variety matching are crucial for herbicide resistance management and effective weed control in Thailand’s rainfed soybean systems. Full article

Insect pests inflict significant agricultural and economic losses on crops globally. Chemical control refers to the use of agrochemicals, such as insecticides, herbicides, and fungicides, to manage pests and diseases. Chemical control is still the prioritized method, as insecticides are highly effective and toxic to insect pests. However, it reduces the quality of the environment, threatens human health, and causes serious 3R (reduce, reuse, and recycle) problems. Current advances in the mining of functional symbiotic bacteria resources provide the potential to assuage the use of insecticides while maintaining an acceptably low level of crop damage. Recent research on insect–microbe symbiosis has uncovered a mechanism labeled “detoxifying symbiosis”, where symbiotic microorganisms increase host insect resistance through the metabolism of toxins. In addition, the physiological compensation effect caused by insect resistance affects the ability of the host to regulate the community composition of symbiotic bacteria. This paper reviews the relationship between symbiotic bacteria, insects, and insecticide resistance, focusing on the effects of insecticide resistance on the composition of symbiotic bacteria and the role of symbiotic bacteria in the formation of resistance. The functional symbiotic bacteria resources and their mechanisms of action need to be further explored in the future so as to provide theoretical support for the development of pest control strategies based on microbial regulation. Full article

Echinochloa spp. are among the most problematic malignant weeds in paddy fields. Under long-term herbicide selection pressure, they have developed resistances to multiple herbicides, leading to diminished control efficacy. Precision herbicide application, tailored to the susceptibility disparities among Echinochloa species, has emerged as a promising strategy to enhance weed control efficacy and decelerate herbicide resistance development. Nevertheless, the herbicide susceptibility variation across different Echinochloa taxa remain uncharted. Therefore, in this study, we determined the susceptibility of five Echinochloa species to 15 commonly used herbicides using the whole-plant bioassay method. Additionally, we explored the feasibility of employing the CDDP molecular marker technique for the rapid identification of distinct Echinochloa species. The results showing that five Echinochloa species exhibited differential susceptibility to 12 of the 15 herbicides tested underscore the necessity of personalized herbicide application strategies. Among the seven CDDP markers, KNOX-3 generated a specific band in the Echinochloa caudata population, which can be used to distinguish it from the other four Echinochloa species. The findings of this study will facilitate the precision application of herbicides for Echinochloa management in paddy fields. Full article

This study evaluated the application of the aqueous extract from Baccharis trimera (Less) DC. in the control of weed species Oryza sativa L. and Cyperus ferax Rich. during the germination and early development stages. Extracts were obtained through pressurized liquid extraction using kinetic assays. Shorter extraction times (1 to 10 min) showed extracts with higher inhibitory effects on seed germination, shoot and root lengths, and fresh and dry mass of the plants. The survival of treated plants was also affected, especially during the early stages of development, reaching up to 40% of mortality. HPLC analysis identified phenolic compounds such as ferulic acid, rutin, quercitrin, and quercetin, with higher concentrations found in the extracts obtained at shorter times of extraction. The reduction in these compounds over longer extraction times was correlated with decreased inhibitory activity. The results indicate that the aqueous extract of B. trimera (Less) DC. holds potential for ecological weed management, standing out as a viable alternative to reduce weed resistance to synthetic herbicides. Full article

The excessive use of synthetic pesticides has not only resulted in increased resistance among weeds and pests, leading to significant economic loss, but has also raised serious health and environmental concerns. Chalcones and their derivatives, known for their herbicidal, fungicidal, bactericidal, and antiviral properties, are emerging as promising bio-based candidates. These naturally occurring compounds have long been recognized for their beneficial health effects and wide-range applications. However, their limited concentration in plants, along with poor solubility and bioavailability, brings challenges for their development. The aim of this study was to examine the properties of a synthetic substance, pinocembrin dihydrochalcone (3-phenyl-1-(2,4,6-trihydroxyphenyl)-1-propanone), including its soil dissipation and adsorption. Additionally, we evaluated its antioxidant activity through the DPPH assay and FRAP experiments. This analysis aims to provide insights into its potential classification as a low risk pesticide. Full article

Abutilon theophrasti Medikus, a pervasive weed infesting transgenic corn fields, exhibits increasing tolerance to glufosinate ammonium—a widely used herbicide in genetically modified cropping systems. This study employed a widely targeted metabolomics approach to investigate differential metabolic responses to glufosinate ammonium across two Abutilon theophrasti populations under identical treatments. A total of 2546 metabolites were detected, predominantly classified into alkaloids, amino acids and derivatives, and flavonoids, among other categories. Three pivotal metabolic pathways (Arginine and proline metabolism, Biosynthesis of amino acids, D-amino acid metabolism) were identified as critical regulators of herbicide response. These findings advance our understanding of weed metabolic adaptation to glufosinate ammonium and lay a foundation for elucidating potential herbicide resistance mechanisms in weeds. Full article

Bee pollination is essential for terrestrial ecosystems and crop production. However, the species richness of wild bees and other pollinators has declined over the past 50 years, with some species experiencing dramatic decreases. A key factor in maintaining bee health is their gut microbiota, which plays an essential role in digestion, nutrient absorption, immune function, and resistance to pathogens. Disruptions to this microbiota can severely impact bee health, rendering them more susceptible to diseases and environmental stressors. Glyphosate, one of the most widely used herbicides, has been extensively studied for its effects on various organisms, with increasing evidence indicating its potential to disrupt bee microbiota. This review explores recent research on the effects of glyphosate and its formulations on the gut microbiota of honeybees and bumblebees. It examines species-specific responses, methodological approaches, and broader ecological implications. While evidence indicates that glyphosate can alter the gut microbiome in some bee species, its effects vary depending on exposure conditions, species, and the composition of microbial communities. Additionally, glyphosate formulations containing surfactants may exacerbate these effects. Given the endocrine-disrupting properties of glyphosate, further research is needed to understand the long-term consequences of exposure, especially its impact on hormonal regulation and bee resilience to environmental stressors. Full article

Weeds present a pervasive challenge in agricultural fields. The integration of herbicide-resistant crops with chemical weed management offers an effective solution for sustainable weed control while reducing labor inputs, particularly in large-scale intensive farming systems. Consequently, the development of herbicide-resistant cultivars has emerged as an urgent priority. In this study, we found that the G311E mutant gene of Arabidopsis MATE (multidrug and toxic compound extrusion) family transporter DTX6, designated DTX6m, confers robust resistance to bipyridyl herbicides paraquat and diquat in rice. DTX6m-overexpression lines exhibited marked resistance to these two herbicides, tolerating diquat concentrations up to 5 g/L, which is five-fold higher than the recommended field application dosage. Agronomic assessments demonstrated that grain yields of DTX6m-overexpressing plants were statistically equivalent to those of wild-type plants. Moreover, the plants displayed beneficial phenotypic changes, such as accelerated flowering and a slight reduction in height. Seed morphometric analysis indicated that in comparison with the wild-type control, DTX6m-transgenic lines exhibited altered grain dimensions while maintaining consistent 1000-grain weight. Nutritional assays further demonstrated that DTX6m increased the levels of free amino acids in seeds, while normal protein and starch contents were retained. Collectively, these results establish that DTX6m effectively boosts rice resistance to paraquat and diquat, validating DTX6m as a candidate gene for engineering plant herbicide resistance and also implying a potential role for DTX6m in amino acid homeostasis in plants. Full article

Based on the complaints of malt barley growers about the insufficient control of rigid ryegrass (Lolium rigidum Gaudin) after applying the ACCase inhibitor pinoxaden, a survey was conducted during the early spring growing season of 2019/20; 20 barley fields located in Thessaloniki and 20 fields in Serres were marked with poor weed control levels. Before the barley harvest, representative weed seeds were collected from all 40 fields. After performing seed germination tests, fourteen populations (six from Thessaloniki and eight from Serres) with the highest seed germination ability were selected for further study. The whole-plant dose–response assays conducted in 2019–2020 indicated that most of the populations were multi-resistant to ACCase and ALS inhibitors. The estimated GR₅₀ values (the herbicide dose required to reduce the fresh weight of treated plants by 50%) for pinoxaden and mesosulfuron-methyl + iodosulfuron-methyl-sodium ranged from 1.15 to 52.41 g ai ha⁻¹ and 4.75 to 31.25 g ai ha⁻¹, respectively. Furthermore, the sequencing of acccase gene fragments from plants that survived pinoxaden application revealed that 11 out of 14 plant populations had a double accase point mutation at Ile1781 and Ile2041 codons. In addition, the sequencing of als gene fragments from the plants that survived mesosulfuron-methyl + iodosulfuron-methyl-sodium application revealed that 11 out of 14 plant populations had a point mutation at the Pro197 codon and 2 of them had a second als mutation at the Trp574 codon. These findings indicate that L. rigidum populations are multi-resistant to ACCase and ALS inhibitors, with individuals exhibiting either double accase or double als mutations. Full article