Tool For Weed Management Research Articles

New Approaches to Herbicide and Bioherbicide Discovery

Abstract During the past 30 yr an impasse has developed in the discovery and commercialization of synthetic herbicides with new molecular targets and novel chemistries. Similarly, there has been little success with bioherbicides, both microbial and chemical. These bioherbicides are needed to combat fast-growing herbicide resistance and to fulfill the need for more environmentally and toxicologically safe herbicides. In response to this substantial and growing opportunity, numerous start-up companies are utilizing novel approaches to provide new tools for weed management. These diverse new tools broaden the scope of discovery, encompassing advanced computational, bioinformatic, and imaging platforms; plant genome–editing and targeted protein degradation technologies; and machine learning and artificial intelligence (AI)-based strategies. This review contains summaries of the presentations of 10 such companies that took part in a symposium held at the WSSA annual meeting in 2024. Four of the companies are developing microbial bioherbicides or natural product–based herbicides, and the other six are using advanced technologies, such as AI, to accelerate the discovery of herbicides with novel molecular target sites or to develop non-GMO, herbicide-resistant crops.

Germination characteristics associated with nicosulfuron resistance in Amaranthus retroflexus L.

Nicosulfuron-resistant biotype (R) and -sensitive biotype (S) Amaranthus retroflexus L. seeds were subjected to different temperature, light, salt, osmotic potential, pH value and burial depth treatments. The difference in germination response of two populations to the above abiotic environmental factors was used to study the fitness cost of nicosulfuron-resistance evolution in A. retroflexus. The aim is to find a powerful tool for weed control in the presence of evolutionary resistance selection. The results of this experiment showed that the germination rate and germination index in S population were generally higher than that in R population. When the salt stress was 80 mM, the water potential was -0.1 Mpa ~ -0.4 Mpa, and under strong acid and alkali conditions, the germination index in S population was prominently higher than that in R population (p<0.05). The delayed seed germination in R population indicated that its nicosulfuron resistance may be linked to seed biochemical compositions that altered seed germination dynamics. The resistant and sensitive biotype of A. retroflexus had differently favourable adaptability in diverse environments. Salt, osmotic potential and pH value are not the major constraints for A. retroflexus germination, however, A. retroflexus are strongly responsive to temperature, light and burial depth. Considering that seeds of A. retroflexus are unable to reach the soil surface beyond the depth of 6 cm, deep inversion tillage before sowing may be an effective and economical weed management tool for the control of nicosulfuron resistant A. retroflexus.

Mapping of flumioxazin tolerance in a snap bean diversity panel leads to the discovery of a master genomic region controlling multiple stress resistance genes.

Effective weed management tools are crucial for maintaining the profitable production of snap bean (Phaseolus vulgaris L.). Preemergence herbicides help the crop to gain a size advantage over the weeds, but the few preemergence herbicides registered in snap bean have poor waterhemp (Amaranthus tuberculatus) control, a major pest in snap bean production. Waterhemp and other difficult-to-control weeds can be managed by flumioxazin, an herbicide that inhibits protoporphyrinogen oxidase (PPO). However, there is limited knowledge about crop tolerance to this herbicide. We aimed to quantify the degree of snap bean tolerance to flumioxazin and explore the underlying mechanisms. We investigated the genetic basis of herbicide tolerance using genome-wide association mapping approach utilizing field-collected data from a snap bean diversity panel, combined with gene expression data of cultivars with contrasting response. The response to a preemergence application of flumioxazin was measured by assessing plant population density and shoot biomass variables. Snap bean tolerance to flumioxazin is associated with a single genomic location in chromosome 02. Tolerance is influenced by several factors, including those that are indirectly affected by seed size/weight and those that directly impact the herbicide's metabolism and protect the cell from reactive oxygen species-induced damage. Transcriptional profiling and co-expression network analysis identified biological pathways likely involved in flumioxazin tolerance, including oxidoreductase processes and programmed cell death. Transcriptional regulation of genes involved in those processes is possibly orchestrated by a transcription factor located in the region identified in the GWAS analysis. Several entries belonging to the Romano class, including Bush Romano 350, Roma II, and Romano Purpiat presented high levels of tolerance in this study. The alleles identified in the diversity panel that condition snap bean tolerance to flumioxazin shed light on a novel mechanism of herbicide tolerance and can be used in crop improvement.

Enhancing productivity and profitability of quinoa through optimization of plant spacing and weeding regimes

ContextWeeds are a major constraint to quinoa production since no herbicide tolerant variety is available worldwide. This raises the importance of cultural practices for controlling weeds. Optimizing plant spacing and implementing effective weeding practices may help to enhance quinoa productivity and profitability. ObjectiveThe objective of current study was to utilize the plant spacing as an alternate option for ensuring effective weed management and profitable quinoa production for the irrigated plains. MethodsThe effect of planting spacing on weed flora in quinoa was evaluated for two consecutive years (2021–22 and 2022–23). Two weeding regimes (weedy and weed-free) along with three plant spacings viz., 10, 20, and 30 cm were tested using a randomized complete block design in split-plot arrangement with three replications. In the weedy plots, no weeding was done, while in the weed-free plots, manual weeding was performed to keep them weed-free throughout the growing season. Results and conclusionsDifferent plant spacing significantly influenced weed biomass and density in quinoa. Narrow spaced plants (10 cm) gave maximum weed suppression as against widely spaced plants (30 cm) and a concomitant yield increase. Medium plant spacing (20 cm) gave maximum grain yield by attaining the optimum plant population under weed-free conditions during both years. Economic analysis also revealed that medium plant spacing with weed-free conditions was beneficial compared to other treatments regarding gross returns, net returns, and benefit-cost ratio. SignificanceThis study highlights that quinoa spacing primarily determined quinoa-weed competition and can be a tool for weed management in this crop.

Three new strategies for improving biosecurity and invasive species management to build resilience in Pacific Islands

The inaugural Pacific Ecological Security Conference (PESC) was held in October 2022, bringing together over 100 island leaders, policy-makers, natural resource managers and global and regional invasive species experts to prioritise the critical issue of invasive species in the Pacific Islands Region. Participants confirmed that invasive species are a major threat to building and maintaining climate resilience and adaptability of Pacific Island ecosystems, as well as food security, biodiversity, sustainable livelihoods and the protection of cultural resources and way of life. Three region-wide strategic action plans were developed to guide interventions focused on the topics of invasive ants, coconut rhinoceros beetle and the use of biological control as a pest and weed management tool. These plans were the major outcome of the PESC and, when implemented, will result in coordinated activities that take a “whole-of-Pacific” approach to invasive species biosecurity and management. Here, we briefly describe the background, planning and engagement process for the three plans, summarise any country- and territory-level data obtained through the process and detail what is planned to occur over the next few years. In addition to the adoption and implementation of the strategies as a result of this inaugural PESC, we anticipate that the PESC will become the premier regional conference aimed at reducing the entry and impacts of invasive species to improve sustainability of environments and peoples of the Pacific.

Soil solarization as a non-chemical weed control method in tree nursery production systems of the Pacific Northwest, USA

IntroductionHerbicide application in tree nurseries is limited because of the potential for chemical injury to the large diversity of trees species grown, the lack of registered products, and increasing restrictions on herbicide use, necessitating the costly practice of hand weeding. Soil solarization can reduce the weed seedbank by trapping solar energy under clear plastic film, resulting in high soil temperatures lethal to imbibed weed seeds and seedlings. The objective of this study was to determine if soil solarization would be an effective weed management strategy in Pacific Northwest, USA, tree production systems.MethodsField studies were conducted at three commercial tree nurseries in Oregon and Washington over two years to test soil solarization in reducing the naturally occurring weed seedbank and the time required to hand weed fields. Further field and laboratory tests were conducted with five weed species: Poa annua, Polygonum pensylvanicum, Amaranthus retroflexus, Portulaca oleracea, and Cyperus esculentus. Weed seeds and tubers were buried in packets at 5 and 10 cm to determine their viability after 6 weeks of solarization. A laboratory study was conducted with all but C. esculentus to quantify the exposure time at 45, 50, and 55°C required for 90% death (T90).ResultsSoil solarization was particularly effective in reducing the emergence of naturally occurring weeds in the fall and winter, when weed emergence was reduced by 94-96%. Emergence was reduced 67-81% during the subsequent spring and early summer. Nine to ten months after solarization, solarized areas had a 52 – 69% reduction in hand weeding time compared to non-solarized areas. In field trials with buried seed and tuber packets, mortality differed by location and depth, with P. annua and P. pensylvanicum having the greatest percent seed mortality followed by A. retroflexus and variable results for P. oleracea and C. esculentus. In lab studies, seed mortality differed depending on species and temperature; however, at 55°C, there was a relatively rapid drop in seed viability for all species, and T90 values ranged from 1.2 to 41 h whereas at 45°C the range was 47 to &amp;gt; 3000 h. Similar to the field studies, P. annua and P. pensylvancium were more sensitive to heat, followed by A. retroflexus and P. oleracea.ConclusionSoil solarization can be an effective weed management tool in reducing the weed seedbank in Pacific Northwest tree nurseries and other fall-sown crops but may not work for certain, thermotolerant weed species such as C. esculentus.

Effect of Herbicides Mixture on Productivity and Profitability of Wheat (Triticum aestivum L.) Cultivation in Rainfed Subtropics

Wheat (Triticum aestivum L.) is a vital cereal crop contributing significantly to global food security. The cultivation of wheat in rainfed subtropical regions faces multifaceted challenges, with weed infestation being a primary concern. Herbicides are crucial tools for weed management, and the synergistic or antagonistic effects of herbicide mixtures have gained attention as potential strategies to enhance their efficacy. This review synthesizes existing literature on the effects of herbicides mixtures on the productivity and profitability of rainfed wheat cultivation in subtropical climates. The review systematically analyzes studies conducted globally, focusing on various herbicides combinations and their application methodologies. It encompasses investigations into the ecological impact, weed control efficiency, and effects on wheat yield when utilizing herbicides mixtures. Special emphasis is placed on understanding the interactions between herbicides, considering factors such as climate, soil characteristics, and cropping practices unique to rainfed subtropics. In addition to agronomic outcomes, this review critically examines the economic aspects associated with the use of herbicides mixtures. Cost-benefit analyses, return on investment, and considerations of long-term sustainability are explored to provide a comprehensive understanding of the profitability implications for farmers engaged in rainfed wheat cultivation. The synthesis of this information aims to guide future research directions, inform agricultural practices, and aid policymakers in formulating sustainable strategies for weed management in rainfed subtropical wheat cultivation. By consolidating the current state of knowledge, this review contributes to the development of evidence-based recommendations for optimizing productivity and profitability while ensuring environmental stewardship in rainfed subtropical wheat production systems.

Mulching as a weed management tool in container plant production - review

Weed management in container plant production is a serious problem and remains one of the most expensive and time-consuming aspects of the industry. Weeds cause severe reductions in crop growth due to the limited growing environment characteristic of container plant production. The container nursery industry relies heavily on a limited number of preemergence herbicide options. The use of herbicides as the primary means to manage weeds has resulted in some negative consequences such as high chemical costs, leaching, runoff, and concerns with recycling irrigation water. Additionally, nursery growers are shifting their focus toward different nonchemical weed management strategies because many ornamental plants are very sensitive to preemergence herbicides. One such method is using organic mulch to control weeds in container plant production. Mulching is the foundation of a nonchemical weed management protocol and acts as the first line of defense against weeds. Organic mulches used in container plant production include rice hulls, pine bark, wood chips, wood shavings, coconut coir, nut (peanut, pecan) shells, oyster shells, cacao bean hulls, pelletized newspaper, recycled newspaper, pine straw, and other materials; material selection often depends on the availability of the product. The objective of this manuscript is to provide a comprehensive review of existing research on the utilization of various mulch materials as a weed management tool in container plant production. Additionally, it aims to highlight any critical knowledge gaps and provide suggestions for possible future research.

Using Glyphosate on Guarana Seedlings in the Amazon.

The seed yield of guarana (Paullinia cupana H.B.K. var. sorbilis) is affected by weeds. Management is difficult for Amazon farmers and ranchers, owing to the hot and humid climate prevailing in the region, which makes mechanical control inefficient and leads farmers to the decision to use herbicides. Herbicide damage to this species is unknown. The objective of this study was to evaluate glyphosate damage to the development and quality of guarana seedlings. The treatments consisted of glyphosate doses at concentrations of 0, 126, 252, 540, 1080, 2160 and 3240 g a.e. ha-1 and were evaluated for 60 days, in two applications. Analyses were performed for biometrics, seedling development, anthracnose and Injury characteristics. Glyphosate caused symptoms of Injury in all doses applied, but lower doses did not interfere with seedling growth and development. There was a correlation between anthracnose severity and increased glyphosate dose. When applied correctly, glyphosate can be an integrated weed management tool for use in guarana crops.

Views of RNAi approaches for weed management in turfgrass systems

AbstractPublic concern regarding the use of herbicides in urban areas (e.g., golf courses, parks, lawns) is increasing. Thus, there is a need for alternative methods for weed control that are safe for the public, effective against weeds, and yet selective to turfgrass and other desirable species. New molecular tools such as ribonucleic acid interference (RNAi) have the potential to meet all those requirements, but before these technologies can be implemented, it is critical to understand the perceptions of key stakeholders to facilitate adoption as well as regulatory processes. With this in mind, turfgrass system managers, such as golf course superintendents and lawn care providers, were surveyed to gain insight into the perception and potential adoption of RNAi technology for weed management. Based on survey results, turfgrass managers believe that cost of weed management and time spent managing weeds are the main challenges faced in their fields. When considering new weed management tools, survey respondents were most concerned about cost, efficacy, and efficiency of a new product. Survey respondents were also optimistic toward RNAi for weed management and would either use this technology in their own fields or be willing to conduct research to develop RNAi herbicides. Although respondents believed that the general public would have some concerns about this technology, they did not believe this to be the most important factor for them when choosing new weed management tools. The need for new herbicides to balance weed control challenges and public demands is a central factor for turfgrass managers’ willingness to use RNAi-based weed control in turfgrass systems. They believe their clientele will be accepting of RNAi tools, although further research is needed to investigate how a wider range of stakeholders perceive RNAi tools for turfgrass management more broadly.

Weed species composition of different peat areas under pineapple plantation in Muar, Johor.

Weeds is the biggest challenge for pineapple production as competing for natural properties such as nutrient, water, sunlight, shelter and others which provided for the pineapple and also act as a host for pest attack. Improper weed management could cause severe weed infestation and reduce pineapple yield specifically in peat soils compared to mineral soils. Peat soils has excellent moisture holding, aeration and physical characteristics for weed germination. Since weed germination was influenced by agronomic changes, this study was conducted to examine weed species composition infested peat soils due to very limited study pertaining this issue. Study was carried out at three different peat areas of pineapple fields in Mukim Ayer Hitam, Muar, Johor. Experiment was done according to the quantitative survey method by using standardized quadrat. Surveying was done several weeks upon herbicides spraying. Broadleaves dominated peat areas compared to grasses, sedges and ferns at all sampling locations. Asystasia gangetica was found as most dominant weed species recorded more than 40% in peat soil regardless the surveyed locations. Asystasia gangetica adapted well in peat soil due to creeping root that remain robust. Proper documentation of dominant weed species infested pineapple plantation particularly in peat soil will be the key tool for sustainable weed management.

Herbicide Physiology and Environmental Fate

Herbicides are crucial tools for weed management in agriculture [...]

Incorporated cover crop residue suppresses weed seed germination

AbstractCover crops have been shown to be important integrated weed management tools. In addition to directly competing with weeds, cover crops can provide weed suppressive effects following incorporation through release of allelopathic compounds and/or changes to nutrient availability. Incorporation of a cover crop mixture may provide a synergistic or antagonistic effect on weed suppression by further altering nutrient dynamics. To investigate this phenomenon, we evaluated the suppressive effects following incorporation of annual ryegrass, buckwheat, brown mustard, and phacelia sown with and without field pea on germination and growth of several pernicious weed species. Further, we used the additive partitioning model to determine if pea synergistically improved biomass production and weed suppression of cover crops. Our results demonstrate that following incorporation, cover crop residues suppress weed germination and weed biomass production. According to the additive partitioning model, the addition of pea had an antagonistic effect on buckwheat and brown mustard biomass production and decreased buckwheat weed suppression by 8%. In contrast, the addition of field pea greatly enhanced biomass production of phacelia at a reduced seeding rate suggesting a positive biodiversity effect. Limited evidence was found for changes to nutrient availability following cover crop incorporation, however, a dose‐dependent effect of cover crop residue on weed suppression suggests allelopathy and/or nutrient availability may have a role on weed seed germination success. Together, our results support the use of incorporated cover crop residues as an integrated weed management tool.

Herbicidal ionic liquids containing double or triple anions as a new potential tool for weed control including herbicide-resistant biotypes

Herbicides are commonly used in modern agriculture for the control of unwanted plants. Contemporary expectations regarding agrochemicals emphasize the need to ensure high effectiveness and reduce side effects. Multicomponent herbicidal ionic liquids possess these features. In planning the syntheses of herbicidal ionic liquids (HILs), we took into account ensuring high activity against weeds using reduced doses of active substances and the problem of controlling herbicide-resistant weeds.Eight new double-anion and eight new triple-anion HILs were synthesized. All obtained HILs contained methyl dodecylbetainate cation and herbicidal anions belonging to both sulfonylurea and auxin-like groups of active substances in a single compound. The new HILs were tested under greenhouse and field conditions and they showed excellent efficacy against target dicotyledonous weeds. Some compounds showed very good surface properties, which are desirable for foliar application to plants. Moreover, HILs with three herbicidal anions (iodosulfuron or metsulfuron + 2,4-D + clopyralid) were very effective against cornflower biotype resistant to acetolactate synthase inhibitors.Our research indicate that herbicidal ionic liquids containing a cation of natural origin and herbicidal anions characterized by a different mode of action in a single compound are a potential new tool for weed management. The use of multicomponent herbicidal ionic liquids enables effective weed control with lower doses of the active ingredient.

Biochemical analysis, photosynthetic gene (psbA) down-regulation, and in silico receptor prediction in weeds in response to exogenous application of phenolic acids and their analogs.

Chemical herbicides are the primary weed management tool, although several incidences of herbicide resistance have emerged, causing serious threat to agricultural sustainability. Plant derived phenolic acids with herbicidal potential provide organic and eco-friendly substitute to such harmful chemicals. In present study, phytotoxicity of two phenolic compounds, ferulic acid (FA) and gallic acid (GA), was evaluated in vitro and in vivo against three prevalent herbicide-resistant weed species (Sinapis arvensis, Lolium multiflorum and Parthenium hysterophorus). FA and GA not only suppressed the weed germination (80 to 60% respectively), but also negatively affected biochemical and photosynthetic pathway of weeds. In addition to significantly lowering the total protein and chlorophyll contents of the targeted weed species, the application of FA and GA treatments increased levels of antioxidant enzymes and lipid peroxidation. Photosynthetic gene (psbA) expression was downregulated (10 to 30 folds) post 48 h of phenolic application. In silico analysis for receptor identification of FA and GA in psbA protein (D1) showed histidine (his-198) and threonine (thr-286) as novel receptors of FA and GA. These two receptors differ from the D1 amino acid receptors which have previously been identified (serine-264 and histidine-215) in response to PSII inhibitor herbicides. Based on its toxicity responses, structural analogs of FA were also designed. Four out of twelve analogs (0.25 mM) significantly inhibited weed germination (30 to 40%) while enhancing their oxidative stress. These results are unique which provide fundamental evidence of phytotoxicity of FA and GA and their analogs to develop cutting-edge plant based bio-herbicides formulation in future.

The Potential of Cover Crops for Weed Management: A Sole Tool or Component of an Integrated Weed Management System?

Cover crops are an important component of integrated weed management programs in annual and perennial cropping systems because of their weed suppressive abilities. They influence weed populations using different mechanisms of plant interaction which can be facilitative or suppressive. However, the question often arises if cover crops can be solely relied upon for weed management or not. In this review we have tried to provide examples to answer this question. The most common methods of weed suppression by an actively growing cover crop include competition for limited plant growth resources that result in reduced weed biomass, seed production, and hence reductions in the addition of seeds to the soil seedbank. Cover crop mulches suppress weeds by reducing weed seedling emergence through allelopathic effects or physical effects of shading. However, there is a great degree of variability in the success or failure of cover crops in suppressing weeds that are influenced by the cover crop species, time of planting, cover crop densities and biomass, time of cover crop termination, the cash crop following in the rotation, and the season associated with several climatic variables. Several studies demonstrated that planting date was important to achieve maximum cover crop biomass, and a mixture of cover crop species was better than single cover crop species to achieve good weed suppression. Most of the studies that have demonstrated success in weed suppression have only shown partial success and not total success in weed suppression. Therefore, cover crops as a sole tool may not be sufficient to reduce weeds and need to be supplemented with other weed management tools. Nevertheless, cover crops are an important component of the toolbox for integrated weed management.

A LuALS Mutation with High Sulfonylurea Herbicide Resistance in Linum usitatissimum L.

The cultivation of herbicide-resistant crops is an effective tool for weed management in agriculture. Weed control in flax (Linum usitatissimum L.) remains challenging due to the lack of available herbicide-resistant cultivars. In this study, a mutant resistant to acetolactate synthase (ALS)-inhibiting herbicides was obtained by ethyl methanesulphonate (EMS) mutagenesis using an elite cultivar, Longya10. Whole-plant dose-response assays revealed that, compared to Longya10, the mutant was 11.57-fold more resistant to tribenuron-methyl (TBM) and slightly resistant to imazethapyr (resistance index (mutant/Longya10) < 3). In vitro acetolactate synthase assays showed that the relative resistance of the mutant was 12.63 times more than that of Longya10. A biochemical analysis indicated that there was a Pro197Ser (relative to the Arabidopsis thaliana ALS sequence) substitution within the LuALS1, conferring high resistance to sulfonylurea herbicides in the mutant. Additionally, two cleaved amplified polymorphic sequence (CAPS) markers, BsaI-LuALS1 and EcoO109I-LuALS1, were developed based on the mutation site for marker assistant selection in breeding. Moreover, the mutant did not cause losses in natural field conditions. We find a mutant with ALS-inhibiting herbicide resistance chemically induced by EMS mutagenesis, providing a valuable germplasm for breeding herbicide-resistant flax varieties.

Tine weeding as a weed management tool for wild blueberry (Vaccinium augustifolium) growers in Maine

Tine weeding as a weed management tool for wild blueberry (<i>Vaccinium augustifolium</i>) growers in Maine

TIA-YOLOv5: An improved YOLOv5 network for real-time detection of crop and weed in the field.

Development of weed and crop detection algorithms provides theoretical support for weed control and becomes an effective tool for the site-specific weed management. For weed and crop object detection tasks in the field, there is often a large difference between the number of weed and crop, resulting in an unbalanced distribution of samples and further posing difficulties for the detection task. In addition, most developed models tend to miss the small weed objects, leading to unsatisfied detection results. To overcome these issues, we proposed a pixel-level synthesization data augmentation method and a TIA-YOLOv5 network for weed and crop detection in the complex field environment. The pixel-level synthesization data augmentation method generated synthetic images by pasting weed pixels into original images. In the TIA-YOLOv5, a transformer encoder block was added to the backbone to improve the sensitivity of the model to weeds, a channel feature fusion with involution (CFFI) strategy was proposed for channel feature fusion while reducing information loss, and adaptive spatial feature fusion (ASFF) was introduced for feature fusion of different scales in the prediction head. Test results with a publicly available sugarbeet dataset showed that the proposed TIA-YOLOv5 network yielded an F1-scoreweed, APweed and mAP@0.5 of 70.0%, 80.8% and 90.0%, respectively, which was 11.8%, 11.3% and 5.9% higher than the baseline YOLOv5 model. And the detection speed reached 20.8 FPS. In this paper, a fast and accurate workflow including a pixel-level synthesization data augmentation method and a TIA-YOLOv5 network was proposed for real-time weed and crop detection in the field. The proposed method improved the detection accuracy and speed, providing very promising detection results.

Allelopathic potential in rice - a biochemical tool for plant defence against weeds.

Rice is a key crop for meeting the global food demand and ensuring food security. However, the crop has been facing great problems to combat the weed problem. Synthetic herbicides pose a severe threat to the long-term viability of agricultural output, agroecosystems, and human health. Allelochemicals, secondary metabolites of allelopathic plants, are a powerful tool for biological and eco-friendly weed management. The dynamics of weed species in various situations are determined by crop allelopathy. Phenolics and momilactones are the most common allelochemicals responsible for herbicidal effects in rice. The dispersion of allelochemicals is influenced not only by crop variety but also by climatic conditions. The most volatile chemicals, such as terpenoids, are usually emitted by crop plants in drought-stricken areas whereas the plants in humid zones release phytotoxins that are hydrophilic in nature, including phenolics, flavonoids, and alkaloids. The allelochemicals can disrupt the biochemical and physiological processes in weeds causing them to die finally. This study insight into the concepts of allelopathy and allelochemicals, types of allelochemicals, techniques of investigating allelopathic potential in rice, modes of action of allelochemicals, pathways of allelochemical production in plants, biosynthesis of allelochemicals in rice, factors influencing the production of allelochemicals in plants, genetical manipulation through breeding to develop allelopathic traits in rice, the significance of rice allelopathy in sustainable agriculture, etc. Understanding these biological phenomena may thus aid in the development of new and novel weed-control tactics while allowing farmers to manage weeds in an environmentally friendly manner.