Search Results (141)

The need to investigate ecological and sustainable approaches to weed management, as well as to reduce the negative environmental impact of chemical herbicides, is becoming increasingly important in modern agriculture and land management. Among alternative strategies, allelopathy is a natural mechanism by which particular plant species release bioactive compounds that can influence the germination, growth, and development of neighboring plants. Harnessing allelopathic interactions offers an opportunity to develop environmentally friendly alternatives to synthetic herbicides and helps preserve ecological balance within agroecosystems. This review examines the potential of allelopathic plant-derived substances for weed control in agricultural systems, with particular emphasis on managing weed populations in vegetable crops and gardens in urban and peri-urban areas. This study introduces the concept of allelopathy with definitions and general information. Subsequently, the paper analyzes the phenomenon’s presence at the plant level, its interactions, and the extracts obtained from allelopathic plants. The paper focuses on essential oils and fatty acid-derived compounds, such as pelargonic acid, which have demonstrated significant inhibitory effects on weed germination and biomass accumulation. Overall, the presented results establish a scientific basis for developing bioherbicides and support implementing sustainable, environmentally responsible horticultural practices. Full article

The effect of sunflower extract on the germination and development of weeds is investigated. However, knowledge about the effects of extracts on target plants is equally important. Investigations into the allelopathic relationship between sunflowers and cereals, which often make up 50–70% of crop rotations, still have many unanswered questions. This experiment aimed to investigate the allelopathic impact of sunflower (Helianthus annuus L.) as a donor plant for spring barley (Hordeum vulgare L.) and spring wheat (Triticum aestivum L.) through their germination and morphological parameters. The following three factors were studied: factor A—two growth stages of the donor plant; factor B—three parts of the donor plant; factor C—five concentrations (0%, 25%, 50%, 75% and 100%) of aqueous extracts of the plant donor. The extract concentration was the strongest factor influencing the germination of spring barley and spring wheat compared to the other two factors. The flowering sunflower extract inhibited the germination of the spring barley and spring wheat by 33–44% and 33–41%, respectively, more strongly than the ripe sunflower extract. According to the SE values, the allelopathic impact of extracts of sunflower parts on spring barley and spring wheat was as follows: L + S < R ˂ H and L + S < H ˂ R, respectively. The inhibitory effect of increasing concentration was determined on the SG, root/shoot length ratio, and SPAD values of both receptor plants. Full article

The invasive weed Malachra capitata is unsuitable for human or animal consumption but has recently attracted attention for potential alternative uses. In this study, the allelopathic potential of M. capitata for weed control was investigated, as were its allelopathic effects on selected crops. The influence of plant developmental stage on its phytotoxic activity was also assessed. In addition, the physiological effects of the extract on seed germination were investigated. Aqueous leaf extracts were obtained across a range of growth stages and evaluated using seed germination and seedling growth bioassays, followed by bioassay-guided fractionation and GC-MS analysis. Leaves extracts collected at 35 days after planting exhibited the strongest inhibitory activity. Dicot plant species (Phaseolus lathyroides, Cucumis sativus, Brassica oleracea, and B. chinensis) were more susceptible to M. capitata extracts than grassy species (Echinochloa crus-galli, Zea mays, and Oryza sativa), indicating selective phytotoxicity. In pot experiments, application of leaf residues as surface mulch at rates of 100, 200, and 400 g/m² significantly reduced P. lathyroides emergence by 11.25%, 35.00%, and 71.25%, respectively. Bioassay-guided fractionation indicated the ethyl acetate-soluble acidic fraction to contain the active allelochemicals. This inhibition was associated with reduced water uptake and suppression of α-amylase activity during seed germination. The most abundant GC-MS detectable components of the acidic fraction were octadecane (12.45%), eicosane (9.74%), and hexadecane (9.60%). Overall, these findings highlight the allelopathic potential of M. capitata, providing a foundation for further applied research and supporting its valorization for sustainable weed management. Full article

Stormwater and greywater are increasingly recognized as freshwater resources, and the effective separation and reutilization of nitrogen (N) and phosphorus (P) from these streams is vital for water quality improvement and urbanization sustainability. In this study, we constructed a pilot-scale hydroponic green roof wetland system planted with two economically important Chinese herbal plant species (Mentha spicata L. (ML) and Basella alba L. (BL)) to separate and reutilize N and P from synthetic stormwater/greywater. The results reveal that the highest plant biomass was obtained at an ML:BL ratio of 1:3, indicating their superior adaptation to rooftop hydroponics with synthetic stormwater/greywater. This configuration also achieved the strongest water purification, with substantial separation and reutilization efficiency of N (82.09%) and P (81.90%). Furthermore, the lowest microbial richness in the ML roots at this specific plant ratio suggested that increasing BL may enhance ML’s allelopathic effects. An increase in the BL proportion was further associated with a gradual shift in the dominant ML root-associated microorganisms toward microeukaryotic taxa. The green vegetation of the two plant species also effectively suppressed algal blooms (especially diatoms) in the hydroponic rooftop system. This study demonstrates that a Chinese herb-based green roof wetland system can effectively separate and reuse N and P from stormwater/greywater while concurrently purifying water and producing economic crops. Full article

Cashew (Anacardium occidentale L.), a vital tropical cash crop, may face yield declines in old plantations due to unexplored risks of autotoxicity. This study investigated the allelopathic and autotoxic potential of cashew plant under laboratory and greenhouse conditions. The laboratory bioassays with leaf and stem bark (10–200 mg) demonstrated a strong allelopathic effect, reducing lettuce radicle elongation to 7–46.0% and 9–79% of the control, respectively. Aqueous leaf extract (50 mg/mL) completely inhibited (0%) lettuce seed germination and reduced pepper germination to 42%. However, the root exudate of cashew seedlings did not have any inhibitory effect on the test plants. Greenhouse experiments simulating field litter fall revealed significant autotoxicity in cashew. Cashew seedlings grown in growth media amended with 10% cashew leaf powder exhibited severe growth suppression after 13 weeks, including a reduction in plant height by 58.2% compared to controls. Chlorophyll content, stem girth, and leaf number were also significantly reduced. This study concludes that cashew possesses significant allelopathic properties and a clear potential for autotoxicity, as directly evidenced by the suppressed growth of its own seedlings following the incorporation of leaf powder. These findings identify autotoxicity, mediated through leaf litter decomposition, as a critical risk factor for the replanting success and long-term sustainability of cashew orchards, necessitating further investigation into management strategies. Full article

Goldenrod (Solidago gigantea Aiton) is a highly invasive species in Europe (e.g., Poland, Germany, and the Czech Republic) whose secondary metabolites can serve as potential sources of bioactive compounds. This study evaluated the phytochemical profile of S. gigantea extracts and evaluated their antibacterial, insecticidal, and phytotoxic activities. The extracts were found to be rich in flavonoids (TFC = 101 mg QE/g) and phenolics (TPC = 175 mg GAE/g), with chlorogenic acid and rutin as dominant constituents. Strong antibacterial activity was observed against Gram-positive bacteria, particularly Staphylococcus spp. (MIC₉₀ = 2.3 mg/mL; MBC = 5 mg/mL), while Gram-negative bacteria were less sensitive, with moderate susceptibility in Rhizobium radiobacter and Pseudomonas syringae. The extract exhibited fungistatic activity against all tested filamentous fungi, with Fusarium species being the most sensitive (49–56% growth inhibition at 10 mg/mL). Insecticidal assays demonstrated significant mortality of Tribolium confusum adults at 2.5–7.0 mg/mL and feeding inhibition at concentrations as low as 0.5 mg/mL. Seedling growth tests showed dose-dependent effects—from mild suppression to moderate stimulation, varying by plant species. Foliar application revealed both stimulatory and inhibitory effects, with the strongest biomass reduction in cress at 10 mg/mL (−45%). These findings indicate that S. gigantea extracts possess potent antibacterial, antifungal, insecticidal, and allelopathic activities. Their concentration-dependent effects on pathogens and plants highlight potential applications in sustainable agriculture, including natural crop protection and integrated pest management. Full article

Sesame (Sesamum indicum L.) is one of the most important oilseed crops globally, valued for its high content of unsaturated fatty acids, proteins, and essential nutrients. However, weed infestation represents a major constraint on sesame productivity, competing for resources and releasing allelopathic compounds that can significantly reduce both yield and quality without timely control. To address the challenge of low detection accuracy in complex agricultural environments with dense weed distributions, this study proposes YOLOv12-BDA, a dynamic multi-scale architecture for small weed detection in sesame fields. The proposed architecture incorporates three key dynamic innovations: (1) an Adaptive Feature Selection (AFS) dual-backbone network with a Dynamic Learning Unit (DLU) module that enhances cross-branch feature extraction while reducing computational redundancy; (2) a Dynamic Grouped Convolution and Channel Mixing Transformer (DGCS) module that replaces the C3K2 component to enhance real-time detection of small weeds against complex farmland backgrounds; and (3) a Dynamic Adaptive Scale-aware Interactive (DASI) module integrated into the neck network to strengthen multi-scale feature fusion and detection accuracy. Experimental validation on high-resolution sesame field datasets demonstrates that YOLOv12-BDA significantly outperforms baseline models. The proposed method achieves mAP@50 improvements of 6.43%, 11.72%, 7.15%, 5.33%, and 4.67% over YOLOv5n, YOLOv8n, YOLOv10n, YOLOv11n, and YOLOv12n, respectively. The results confirm that the proposed dynamic architecture effectively improves small-target weed detection accuracy at the cost of increased computational requirements (4.51 M parameters, 10.7 GFLOPs). Despite these increases, the model maintains real-time capability (113 FPS), demonstrating its suitability for precision agriculture applications prioritizing detection quality. Future work will focus on expanding dataset diversity to include multiple crop types and optimizing the architecture for broader agricultural applications. Full article

Cenchrus setaceus is an alien invasive species with significant ecological impact on both natural ecosystems and agricultural areas across the Canary Islands. In this study, we evaluated the allelopathic effects of foliar lixiviates from two endemic species, Artemisia thuscula and Plocama pendula, on Cenchrus setaceus and a group of crop species to assess (i) germination inhibition of the invasive species and (ii) selectivity towards non-target crops. A preliminary trial tested undiluted and diluted forms (1%, 10%) of concentrated lixiviates prepared at a 1:3 (w:v) leaf-to-water ratio, using C. setaceus and Lactuca sativa under growth chamber conditions. In the validation trial, lixiviates prepared at a 1:6 (w:v) ratio were applied directly to C. setaceus and seven crops (Zea mays, Allium cepa, Hordeum vulgare, L. sativa, Solanum lycopersicum, Brassica oleracea, and Raphanus sativus) under both growth chamber and greenhouse conditions. Germination indices were calculated across assays, and plumule and radicle lengths were measured in growth chamber assays. In both trials, C. setaceus germination was inhibited by up to 60% by both ratios of lixiviates (Dunn p < 0.05), with reduced speed and seedling growth (plumule: −37.5%; radicle: −85%). Crop sensitivity varied: A. cepa and H. vulgare showed no significant inhibition; B. oleracea and R. sativus were affected by P. pendula (germination reduced 2.5–2.7×); and Z. mays, L. sativa, and S. lycopersicum exhibited delayed germination and reduced seedling growth under both treatments. These results support the selective use of native plant lixiviates for integrated management of Cenchrus setaceus in sensitive agroecosystems. Full article

Challenges significantly hinder the sustainable cultivation of tea chrysanthemum, leading to imbalances in soil nutrients, the accumulation of allelopathic phenolic acids, reduced enzymatic activity, and disruptions in rhizosphere microbial communities. To explore potential mitigation strategies, this study systematically evaluated the integrative effects of exogenous methyl jasmonate (MeJA, 0–400 (μmol L⁻¹)) on both soil environmental parameters and plant growth performance under continuous cropping conditions. The results revealed that treatment with 100 (μmol L⁻¹) MeJA significantly enhanced plant height, canopy width, flower number, and fresh flower weight. Concurrently, it improved soil organic matter content, the available nitrogen levels, and redox stability while increasing the activity of key enzymes, including polyphenol oxidase, urease, and catalase. Notably, this treatment markedly reduced the accumulation of allelopathic phenolic acids, such as p-hydroxybenzoic acid and vanillic acid. High-throughput sequencing further demonstrated that 100 (μmol L⁻¹) MeJA optimized the composition of soil microbial communities, increasing the abundance of beneficial taxa, such as nitrogen-fixing and phosphate-solubilizing bacteria, while suppressing pathogenic fungi. Metabolomic analysis showed that this concentration of MeJA activated stress-resistance metabolic pathways involving flavonoids and terpenoids while downregulating degradation-related processes, thereby supporting enhanced plant resilience at the metabolic level. Collectively, these findings demonstrate that an appropriate concentration of exogenous MeJA can effectively alleviate continuous cropping obstacles in Chrysanthemum morifolium, providing both theoretical insights and practical guidance for its eco-friendly and efficient cultivation. Full article

Tolprocarb (TPC), a fungicide primarily used for controlling rice blast, was recently shown to stimulate disease resistance in rice. To elucidate the molecular basis of this immunostimulatory effect, we conducted transcriptomic, metabolic, and field-based analyses focusing on diterpenoid phytoalexins, key antimicrobial and allelopathic compounds in rice. Microarray analysis revealed that TPC treatment induced a broad transcriptional activation of genes involved in phytoalexin biosynthesis, including DPF, a master regulator of diterpenoid metabolism. Consistent with this, LC-MS/MS analyses confirmed the accumulation of momilactones A and B, as well as phytocassanes B, C, and E, in rice leaves after TPC application, a response not observed with conventional resistance inducers such as probenazole or carpropamid. In root tissues under controlled conditions, phytoalexin accumulation was limited, and exudation into the rhizosphere was minimal. However, field experiments showed that TPC treatment led to a transient increase in leaf momilactones around 14 days post-transplanting, followed by increased exudation into the rhizosphere at 21 days. Notably, this increase in root exudation coincided with a reduction in total weed biomass, although weed species composition remained unchanged. These findings suggest that TPC not only enhances rice immunity through phytoalexin induction but may also contribute to weed suppression via allelopathic root exudates in field settings. Our study highlights a dual role for TPC in rice cultivation, boosting disease resistance and suppressing weed growth, and underscores the potential of phytoalexin-focused strategies for integrated crop protection. Full article

Cover crops provide soil cover benefits but can impose allelopathic risks on cotton. We evaluated the functional trade-offs of rye and wheat residues versus purified 2-benzoxazolinone (BOA) under greenhouse conditions. Four experiments applied graded residue or BOA inputs in Pullman clay loam; cotton germination, height, chlorophyll (SPAD), and biomass were measured, and soil BOA, DIBOA, and DIMBOA were quantified by HPLC at designated sampling dates. Responses were dose dependent: BOA reduced germination linearly (−16.5% at 1000 nmol g⁻¹ versus control) and shortened plants, and biomass and SPAD were directionally lower, most evident at 500 nmol g⁻¹, but not statistically significant. Rye showed hormesis at 6400 kg ha⁻¹ (+7.3% germination) and strong inhibition at 12,800 kg ha⁻¹ (−31% germination; biomass up to −45%). Wheat produced intermediate inhibition (biomass −23.7%) and did not affect germination. In soil, benzoxazinoids exhibited significant rate effects at specific sampling dates followed by rapid decline. After storage, BOA showed no residual effects, whereas prior rye still reduced height, SPAD, and biomass. Framed at the agroecosystem scale, maintaining residue biomass below inhibitory thresholds and adjusting termination-to-planting intervals to avoid the early post-termination period, together with species or cultivar choice, can reconcile soil cover services with reliable cotton establishment. 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

Salvia pratensis L. is a valuable medicinal plant rich in bioactive compounds, yet its allelopathic potential remains underexplored. This study evaluated allelopathic effects and total phenolic (TPC) and flavonoid (TFC) contents of water extracts from the dry aboveground biomass of S. pratensis. To assess their selectivity and potential application in sustainable weed management, extracts at five different concentrations were tested on the germination and early growth of lettuce, radish, tomato, and carrot. The results demonstrated that the phytotoxic effects of S. pratensis extracts were both concentration- and species-dependent. Higher extract concentrations significantly inhibited germination and seedling growth, while lower concentrations of extracts stimulated shoot elongation by up to 30% compared to the control. Phytochemical analysis revealed that S. pratensis extracts contain notable TPC and TFC contents, with their concentrations increasing consistently with the extract concentration. Correlation analysis showed that higher TPC and TFC contents were strongly negatively correlated with germination and seedling growth parameters. Radish exhibited the highest sensitivity to the extracts, while lettuce was the most tolerant. Further research under field conditions is needed to assess the efficacy, selectivity, and practical potential of S. pratensis extracts in sustainable crop production systems. Full article

Nitrogen (N) cycling in agroecosystems is a complex process regulated by both biological and agronomic factors, with ammonia-oxidizing archaea (AOA) and bacteria (AOB) playing pivotal roles in nitrification. Despite extensive fertilizer applications to achieve maximum crop yields, nitrogen use efficiency (NUE) remains less than ideal, with substantial losses contributing to environmental degradation. This review synthesizes current knowledge on plant-mediated and fertilization-induced shifts in ammonia-oxidizer communities and their implications on nitrogen cycling. We highlight the differential ecological niches of AOA and AOB, emphasizing their responses to plant community composition, root exudates, and allelopathic compounds. Fertilization regimes of inorganic nitrogen inputs and biological nitrification inhibition (BNI) are examined in the context of microbial adaptation and ammonia tolerance. Our review highlights the need for integrated nitrogen management strategies comprising optimized fertilization timing, nitrification inhibitors, and plant–microbe interactions in order to optimize NUE and mitigate nitrogen losses. Future research directions must involve applications of metagenomic and isotopic tracing techniques to unravel the mechanistic AOA and AOB pathways that are involved in regulating these dynamics. An improved understanding of these microbial interactions will inform the creation of more sustainable agricultural systems that aim to optimize nitrogen retention and reduce environmental footprint. Full article

This study investigates the allelopathic potential of two invasive plants from the Asteraceae family, Erigeron canadensis L. and Erigeron annuus (L.) Desf., which are prevalent in Heilongjiang Province, China. We systematically examined the effects of water extracts from these plants at various concentrations (25, 50, 75, and 100 g·L⁻¹) on the germination and seedling growth of three major food crops: wheat (Triticum aestivum L.), rice (Oryza sativa L.), and corn (Zea mays L.). Using the Petri dish method and two-way ANOVA with SPSS27 software, we assessed the interaction effects of species and concentration on these crops. The results revealed differential chemosensory effects between E. canadensis and E. annuus extracts. Specifically, the aqueous extract of E. canadensis at 25 g·L⁻¹ promoted wheat root length, while all other growth indicators showed inhibitory effects. The inhibitory effects on wheat, rice, and maize increased with the concentration of the leaching solution. At 100 g·L⁻¹, E. annuus extract completely inhibited the germination of wheat and rice, with an integrated sensitization effect index of −1. The inhibitory effects of the extracts on seed growth indices were in the order of shoot length > root length > biomass. Wheat was the most affected among the three crops, followed by rice, and maize was the least affected. The allelopathic potential of E. annuus was more substantial than that of E. canadensis. Full article