Search Results (436)

Acacia mearnsii De Wild. has been introduced to over 150 countries for its economic value. However, it easily escapes from plantations and establishes monospecific stands across plains, hills, valleys, and riparian habitats, including protected areas such as national parks and forest reserves. Due to its negative ecological impact, A. mearnsii has been listed among the world’s 100 worst invasive alien species. This species exhibits rapid stem growth in its sapling stage and reaches reproductive maturity early. It produces a large quantity of long-lived seeds, establishing a substantial seed bank. A. mearnsii can grow in different environmental conditions and tolerates various adverse conditions, such as low temperatures and drought. Its invasive populations are unlikely to be seriously damaged by herbivores and pathogens. Additionally, A. mearnsii exhibits allelopathic activity, though its ecological significance remains unclear. These characteristics of A. mearnsii may contribute to its expansion in introduced ranges. The presence of A. mearnsii affects abiotic processes in ecosystems by reducing water availability, increasing the risk of soil erosion and flooding, altering soil chemical composition, and obstructing solar light irradiation. The invasion negatively affects biotic processes as well, reducing the diversity and abundance of native plants and arthropods, including protective species. Eradicating invasive populations of A. mearnsii requires an integrated, long-term management approach based on an understanding of its invasive mechanisms. Early detection of invasive populations and the promotion of public awareness about their impact are also important. More attention must be given to its invasive traits because it easily escapes from cultivation. 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

Moringa (Moringa oleifera Lam.) is widely recognised as a multipurpose crop suitable for human and animal consumption, medicinal, and industrial purposes, making it attractive for introduction into new ranges. Its extracts have been found to have beneficial impacts on various crop species and biological activity against multiple weeds, making their use in agriculture promising. However, concerns have also been raised about moringa’s potential to negatively impact the growth and development of other cultivated and non-cultivated plant species, especially in areas where it has been introduced outside its native range. To understand the positive and negative interactions between moringa and other plants, it is essential to investigate its allelopathic potential. Allelopathy is a biological activity by which one plant species produces and releases chemical compounds that influence the reproduction, growth, survival, or behaviour of other plants with either beneficial or detrimental effects on the receiver. Plants produce and release allelochemicals by leaching, volatilisation, or through root exudation. These biochemical compounds can affect critical biological processes such as seed germination, root and shoot elongation, photosynthesis, enzymatic activities, and hormonal balance in neighboring plants. Therefore, allelopathy is an important driver of plant composition and ecological interactions in an ecosystem. This review explores the positive and negative allelopathic effects of moringa extracts on other plant species, which may help to inform decisions regarding its introduction into new biogeographical regions and incorporation into existing farming systems, as well as the use of moringa plant extracts in agriculture. Full article

Sorghum halepense (L.) Pers. (common name Johnson grass) is a perennial invasive weed that causes great harm worldwide, and its allelopathy has been demonstrated in a series of experiments. The present study offers new insights into its organ-specific phytochemical profiles using state-of-the-art metabolomic technology and explores the effects of a methanol extract of S. halepense rhizomes (ShER) and its major bioactive compounds (p-hydroxybenzoic acid and chlorogenic acid) on three noxious weed species. The phytotoxic effects of ShER are reflected through the inhibition of seed germination and reduced seedling growth, which are accompanied by changes in the antioxidant system of seedlings. Phytotoxicity is species specific and concentration dependent, and it is more pronounced against Chenopodiastrum murale (L.) S. Fuentes, Uotila & Borsch and Datura stramonium L. than highly tolerant Amaranthus retroflexus L. Catalase (CAT) is most likely the major mediator in the removal of reactive oxygen species, which are generated during germination and early seedling growth of Ch. murale exposed to ShER. The results of the present study imply the high potential of ShER in the management of amaranthaceous and solanaceous weeds, such as Ch. murale and D. stramonium, respectively. The present study offers an environmentally friendly solution for the biological control of weeds belonging to the families Amaranthaceae and Solanaceae. Also, the results of this research highlight the possibility of effective management of S. halepense by using it as a feedstock for bioherbicide production. Full article

Biopesticides represent a safe and sustainable strategy for biological pest management, applicable to weed and fungal control. Biotechnological processing offers a promising approach to enhance the bioactivity of natural products for agricultural use. In this study, guishe juice, an agroindustrial residue derived from Agave lechuguilla, was bioprocessed via inoculation with Fusarium chlamydosporum, and its fungicidal and herbicidal potentials were evaluated. The fungal biotransformation led to the accumulation of phytochemicals, including flavonoids and polyphenols, significantly enhancing antioxidant activity to 76% and 96% as measured by DPPH and ABTS assays, respectively. The resulting bioprocessed guishe extract (BGE), particularly at 10% concentration (BGE-10), exhibited strong fungicidal activity, achieving 100% control of phytopathogenic fungi Fusarium spp. and Penicillium spp. Additionally, BGE-10 demonstrated a bioherbicidal effect, with a 77% weed control rate against Verbesina encelioides. These findings emphasize the potential of bioprocessed agave residues as dual-action bioagents, supporting the development of novel, eco-friendly agricultural solutions. Full article

Xinjiang larch (Larix sibirica Ledeb.) is a keystone species in the Altay Mountains, playing a vital role in maintaining ecosystem stability. This study investigates how different soil preparation techniques (ring, strip, and burrow) influence seed germination and seedling establishment by mitigating apomictic allelopathy. Experimental plots were established using artificial seeding and natural seed dispersal at soil depths of 5 cm, 10 cm, and 15 cm. Seedling survival and development were monitored in June, July, and August 2023. The results demonstrated that sod removal significantly enhanced seed germination by reducing allelopathic inhibition, improving seed–soil contact, and increasing moisture retention. Among the techniques, the ring method yielded the highest rates of seedling establishment, particularly when artificial seeding was combined with natural seed dispersal. Although seedling numbers tended to increase with soil depth, the differences were not statistically significant. Temporal dynamics revealed a peak in seedling survival in July, followed by a subsequent decline. These findings highlight the critical role of optimized soil preparation techniques in promoting successful seedling development. The study offers practical guidance for ecological restoration and sustainable forest management in degraded larch ecosystems of the Altay Mountains. Full article

Lolium perenne (Poaceae), a perennial forage, has high economic and nutritional value. It is often used as a replacement control for some invasive plants, as it has achieved good ecological and economic effects. However, its control effects, allelochemicals, allelopathic effects, release pathways, and contents are still unclear in the process of L. perenne replacement control of an invasive plant, Ageratina adenophora (Asteraceae). Therefore, it is necessary to reveal the mechanism of L. perenne replacement control of A. adenophora from the perspective of allelopathy. In this study, L. perenne could effectively inhibit the growth of A. adenophora in the competition assay. In addition, seven norsesquiterpenes (1–7) were isolated and identified from the whole plant of L. perenne, and most of the compounds exhibited potent allelopathic effects on the growth of A. adenophora and one model plant (Lactuca sativa, Asteraceae). Moreover, some active compounds were released into the environment through root secretion and rainwater leaching, and their contents were determined by UPLC-MS/MS (Ultra Performance Liquid Chromatography Tandem Mass Spectrometry). Our results elucidated the allelopathic mechanism of L. perenne’s replacement control, A. adenophora, and provided a theoretical basis for the development of norsesquiterpenes from L. perenne. Full article

Hakea decurrens subsp. physocarpa is an invasive species from Australia, with morphological, physiological and ecological features that help it colonize and settle outside of its natural habitats. One of these characteristics is allelopathy, which is an interaction that grants a clear competitive advantage to invasive species that has not been studied in H. decurrens subsp. physocarpa. With the aim of understanding the ecological relationships that take place in habitats invaded by this species, it is especially important to know the allelopathic potential of H. decurrens subsp. physocarpa and the compounds that would be involved in this interaction. To this end, the present study quantified the allelopathic activity of the aqueous extract of leaves gathered on four different occasions in the year, as well as of the compounds present in these extracts. The obtained results show a negative effect of H. decurrens subsp. physocarpa samples collected in March, June, September, and December on the germination and growth of Lactuca sativa. Although the negative effect was observed with all extracts, the extract of leaves gathered in September showing the greatest effect on germination (I₅₀ = 0.08 g/mL), and that of leaves collected in June presented the greatest effect on root size (I₅₀ = 0.05 g/mL). As for the composition of these extracts, nine compounds were identified and quantified through HPLC: arbutin, mesaconic acid, isotachioside, 1-O-vanilloyl-beta-D-glucose, syringic acid-4-beta-D-glucopyranoside, quercetin 3-robinobioside-7-glucoside, quercetin 3-rhamninoside, rutin, and isorhamnetin-3-O-rutinoside. There is a correlation between the quantified parameters and the quantity of these compounds in the extracts, but it is difficult to attribute the allelopathic activity of H. decurrens subsp. physocarpa to a particular compound, since this activity may depend on the combination of these compounds. In conclusion, this work demonstrates that the leaves of the invasive species H. decurrens subsp. physocarpa have allelopathic potential, and their toxicity could be due to the combined action of these compounds, which should be analyzed in future studies. Full article

Plant allelochemicals can affect the germination and growth of other plant species. Petri and pot experiments were conducted to detect the interaction of Amaranthus palmeri with cereals (barley, oat, wheat, and triticale). Aqueous extracts of different tissues of A. palmeri and cereals at several concentrations were used to measure the inhibitory effects on the germination of other plants in the Petri experiments. A. palmeri plants and cereals grown at two different densities were incorporated into a potting mix at two different growing stages to determine the inhibitory effects on the germination and growth of other plants in pot experiments. The relative germination inhibition of A. palmeri was present in the following order: barley > oat > triticale > wheat. The relative germination inhibition of cereals was present in the following order: oat > triticale > barley > wheat. The above-ground parts of the plants were more effective than the roots. The germination of A. palmeri was only affected by wheat, while barley was better at reducing the dry weight in pot experiments. Wheat was found to be the only cereal affected by A. palmeri. Despite the prevailing hypothesis that these plants do not affect each other’s germination and development in nature, it was concluded that using wheat and barley as a cover crop can support A. palmeri management, and delaying wheat planting in the presence of A. palmeri can protect cereals from allelopathic interference. Full article

Epiphytic lichens are integral to boreal forest ecosystems, yet their allelopathic interactions with host trees, particularly in cryolithozone regions, remain poorly understood. This study elucidates the physiological and biochemical impacts of the epiphytic lichen Physcia alnophila on Larix gmelinii (Gmelin larch), a keystone species in Siberian permafrost forests. By combining dendrochronology, GC–MS metabolomic analysis, and HPLC–ESI–MS/MS analysis, we demonstrate that the lichen’s primary metabolite, atranorin (ATR), systemically migrates from thalli into the host’s cambium, roots, and needles, with root accumulation reaching 36.3 µg g⁻¹ DW. Lichen-colonized trees exhibited severe radial growth inhibition (27%–51% reduction over five years) and suppressed apical growth, despite comparable heights to controls, indicating chronic phytotoxicity. Metabolomic profiling revealed lichen-specific polyols (e.g., arabitol, mannitol) in larch tissues, alongside elevated stress biomarkers (terpenes, sterols, phenolic acids), and significant disruptions to the tricarboxylic acid cycle and oxidative phosphorylation. These metabolic perturbations correlate with reduced monosaccharide availability and impaired energy production, directly linking ATR translocation to growth suppression. L. gmelinii exhibited compensatory responses, including increased fatty acids and arabinogalactan synthesis, suggesting adaptive mechanisms to mitigate lichen-induced stress. Our findings suggest P. alnophila as a biotic stressor that affects tree physiology in extreme climates, with implications for boreal forest resilience. This work provides an insight to the rarely pointed out species interactions, which, when combined with climate change, may alter carbon cycling and forest dynamics in permafrost ecosystems. Full article

Allelopathy plays a major role in agricultural production, influencing plant protection, crop yield, and crop rotation systems. This study investigated the effects of root exudates on 3105c alfalfa (Medicago sativa) seeds and seedlings to identify crops with strong and weak allelopathic potential. The results revealed that corn (Zea mays L.) (T1) exhibited the strongest allelopathic effects, whereas soybean (Glycine max (Linn.) Merr.) (T10) exhibited the weakest effects. T1 promoted seed germination by increasing radicle length and the simple vitality index. Both T1 and T10 promoted 3105c seedling growth and enhanced antioxidant capacity, albeit through different mechanisms. T1 primarily increased antioxidant capacity by elevating ascorbate and dehydroascorbate levels while reducing malondialdehyde content. In contrast, T10 enhanced antioxidant capacity by increasing soluble sugar and protein levels via hydroxyl free radical inhibition. These findings demonstrate that the allelopathic properties of corn effectively promote alfalfa growth by enhancing seed germination and improving physiological stress resistance. Full article

(4Z,8Z)-Matricaria lactone (MAT) and (4Z)-lachnophyllum lactone (LAC) are natural acetylenic furanones with bioherbicidal potential. This study evaluates their possibilities and ecotoxicological impact on aquatic (Aliivibrio fischeri, Raphidocelis subcapitata, and Daphnia magna) and terrestrial (Caenorhabditis elegans, Lepidum sativum) model organisms. MAT exhibited rapid degradation, with 90% decomposition within 24 h and over 98% by day 16, while LAC was more stable, degrading by only 8.5% in 24 h and 67% by day 16. Despite its rapid breakdown, MAT exhibited higher acute toxicity to A. fischeri (EC₁₀ = 0.063 mg L⁻¹; EC₅₀ = 0.642 mg L⁻¹) compared to LAC (EC₁₀ = 0.524 mg L⁻¹; EC₅₀ = 8.078 mg L⁻¹). Toxicity patterns in R. subcapitata differed, with MAT promoting slightly higher growth compared to the control, suggesting hormetic effects (EC₁₀ = 3.417 mg L⁻¹; EC₅₀ = 4.520 mg L⁻¹), while LAC inhibited growth concentration (EC₁₀ = 0.304 mg L⁻¹; EC₅₀ = 9.880 mg L⁻¹). Both compounds immobilized D. magna, with LAC showing greater delayed toxicity (EC₅₀ = 1.728 mg L⁻¹ vs. MAT EC₅₀ = 2.239 mg L⁻¹). Furthermore, for L. sativum, there were no effects on the germination, but effects were observed in the lengths of the shoots (LAC EC₅₀ = 85.89 mg L⁻¹ vs. MAT EC₅₀ = 82.30 mg L⁻¹). In contrast, C. elegans showed no mortality, suggesting lower terrestrial toxicity. These findings suggest that MAT and LAC may pose risks to aquatic ecosystems through runoff or leaching, necessitating further studies on their degradation products, soil microbiota, and non-target terrestrial organisms. Comparative analyses with conventional herbicides highlight MAT and LAC as selective, lower-impact alternatives. Future research should focus on their effects on terrestrial organisms, the ecological safety of degradation products, and large-scale bioassays to ensure their sustainability in agriculture. Full article

Root exudates, compounds secreted by plant roots, play a crucial role in plant–soil interactions and have significant agricultural implications. These substances influence nutrient availability, plant growth, and the surrounding rhizosphere. This review examines the composition, mechanisms, and importance of root exudates, categorizing them as diffusates, secretions, and excretions, each with specific release methods and functions. It highlights the allelopathic effects of root exudates, showing how plants use them to inhibit competitors through chemical signals and nutrient changes. Case studies on crops such as wheat and rice demonstrate the practical relevance of root exudates in agriculture. This review emphasizes the need to understand root exudates to improve sustainable farming and weed control strategies. Full article

Utilizing nanotechnology for weed management offers a sustainable alternative to synthetic herbicides. This study evaluated the effectiveness of sunn hemp extract (SH), Fe₃O₄ nanoparticles (NPs), and Fe₃O₄/sunn hemp NPs in inhibiting the germination of redroot pigweed (Amaranthus retroflexus L.), wild mustard (Sinapis arvensis L.), and lamb’s quarters (Chenopodium album L.) weeds. The structural characteristics of the NPs were analyzed using Scanning electron microscopy (SEM), Scanning X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Vibrating sample magnetometer (VSM), Brunner–Emmet–Teller (BET), and Fourier-transform infrared spectroscopy (FTIR). The optimal Fe₃O₄ NP concentration for reducing seed germination ranged from 3000 to 3100 mg L⁻¹. Higher concentrations of SH extract (100, 150, and 200 g L⁻¹) effectively inhibited weed seed germination with A. retroflexus displaying the highest sensitivity. The maximal effective concentration (NOEC_max) for Fe₃O₄/sunn hemp NPs was 10 g L⁻¹ for S. arvensis, 150 g L⁻¹ for A. retroflexus, and 200 g L⁻¹ for C. album. Fe₃O₄/sunn hemp NPs led to a reduction in 1/D₅₀ and an increase in EEC₅₀, indicating a rise in sensitivity to Fe₃O₄ NPs, particularly in S. arvensis. Variations in species responses to SH, Fe₃O₄ NPs, and Fe₃O₄/sunn hemp NPs are likely influenced by genetic, physiological, and ecological factors. Overall, the findings suggest that utilizing Fe₃O₄/sunn hemp NPs offers an effective strategy for sustainable weed management. Full article