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Soil contamination by toxic metals threatens global public health, highlighting the need for cost-effective and ecologically sound site remediation. In this study, we assessed phytoremediation of Hg-contaminated soils by Emilia fosbergii Nicolson (Asteraceae). Pot experiment was conducted using a substrate of sand and vermiculite (1:1 volume ratio), treatments consisted of five Hg concentrations (0, 1, 3, 5, and 7 mg kg−1). Metal transfer rates were calculated, including accumulation (BAF), translocation (TF) and bioconcentration (BCF) factors. E. fosbergii roots exhibited greater Hg accumulation than other tissues, but biomass production and plant health were not significantly affected at the concentrations tested, as indicated by elongation factors and tolerance index. The results revealed BAF values between 2.18 and 7.14, TF values ranged between 0.15 and 0.52, and the BCF index varied between 8.97 and 26.58. Treatments with Hg content of 5 mg kg−1 and 7 mg kg−1 recorded the highest total Hg concentrations of 66 mg kg−1 and 65.53 mg kg−1 (roots), and 9.18 mg kg−1 and 33.88 mg kg−1 (aerial), respectively. E. fosbergii demonstrated promise for Hg phytoremediation due to its high accumulation capacity, indicated by regular TF and high BCF and BAF indexes, thus classifying it as a high Hg accumulator. Phytoextractor and phytostabilizer plant, high accumulator of Hg. Weed with great capacity for proliferation and adaptability. E. fosbergii showed tolerance to Hg in the substrate. Promising plant for phytoremediation of soils contaminated by Hg. Novel species for recovery of soils degraded by Hg exposure. [ABSTRACT FROM AUTHOR]

Weedy rice, a pervasive and troublesome weed found across the globe, has often evolved through fertilization of rice cultivars with little importance of crop‐weed gene flow. In Argentina, weedy rice has been reported as an important constraint since the early 1970s, and, in the last few years, strains with herbicide‐resistance are suspected to evolve. Despite their importance, the origin and genetic composition of Argentinian weedy rice as well its adaptation to agricultural environments has not been explored so far. To study this, we conducted genotyping‐by‐sequencing on samples of Argentinian weedy and cultivated rice and compared them with published data from weedy, cultivated and wild rice accessions distributed worldwide. In addition, we conducted a phenotypic characterization for weedy‐related traits, a herbicide resistance screening and genotyped accessions for known mutations in the acetolactate synthase (ALS) gene, which confers herbicide resistance. Our results revealed large phenotypic variability in Argentinian weedy rice. Most strains were resistant to ALS‐inhibiting herbicides with a high frequency of the ALS mutation (A122T) present in Argentinian rice cultivars. Argentinian cultivars belonged to the three major genetic groups of rice: japonica, indica and aus while weeds were mostly aus or aus‐indica admixed, resembling weedy rice strains from the Southern Cone region. Phylogenetic analysis supports a single origin for aus‐like South American weeds, likely as seed contaminants from the United States, and then admixture with local indica cultivars. Our findings demonstrate that crop to weed introgression can facilitate rapid adaptation to agriculture environments. [ABSTRACT FROM AUTHOR]

Planting density (PD) is an important management practice that plays a crucial role in crop growth and weeds infestation. Weeds control methods also play an indispensable role to control the weeds infestation. Therefore, present study was conducted to determine the effect of different weed control methods and PD on growth, yield and quality of maize grown under semi-arid conditions. The study was comprised of weedy season, weed free, S-metalachlor @ 1920 g a.i. ha−1, S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1, mesotrione + atrazine @ 687.5 g a.i. ha−1, S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1 + mesotrione and atrazine @ 687.5 g and different PD; 12 and 20 cm. The results indicated that taller plants with maximum rows/cob, cob length, grains/cob, 1000 grain weight (GW), grain yield, biological yield and harvest index (HI) during both years was recorded in 20 cm apart plants with application of S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1 + mesotrione and atrazine @ 687.5 g ha−1 and lowest yield and yield traits were observed in 12 cm spaces plants with fully weeds. However, lowest weed density and weeds biomass was recorded in 12 cm apart plants with l weed free followed by application of S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1 + mesotrione and atrazine @ 687.5 g ha−1 and maximum weed density and weed biomass broad PD (12 cm) with weedy check. Additionally, maximum concentration of carbohydrate, protein and starch was also recorded in narrow PD (12 cm)) with application of S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1 + mesotrione and atrazine @ 687.5 g and lowest concentration of carbohydrate, protein and starch was recorded in 12 cm spaced plants with weedy check. Therefore, combination of 20 cm spaced plants and application of S-metolachlor + atrazine @ 740 g a.i. ha−1 + 550 g a.i. ha−1 + mesotrione and atrazine @ 687 could be an promising approach to get better maize productivity in semi-arid regions. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is the fourth major crop grown as a staple food worldwide, following rice, wheat, and maize. It is highly susceptible to diseases, nematodes, insect pests, and weeds. Potato yield loss due to weeds varies from 10 to 80% depending on the environment, weed diversity, density, and period of the weed-crop competition. High weed interference may decrease 65% of marketable tuber yield by reducing the number and size of marketable tubers. Weeds not only decrease potato tuber yield but also negatively influence the antioxidant enzymatic activity and primary metabolites of the potato plant. Estimates have shown that the starch content of potato tuber decreases by 10% and protein content by 36% in potato-weed competition. These findings suggest that weed competition can substantially impact potato growth and development and that effective weed management strategies are critical for optimizing potato yields and quality. This review summarizes the recent progress on how potato plants initially respond to weed interference at morphological, biochemical, and physiological levels. [ABSTRACT FROM AUTHOR]

Weed control is one of the major challenges in rice cultivation, and the use of agrochemicals for this crop is severely restricted under the new European agricultural policy. Therefore, new effective non‐chemical weed control techniques are the key to sustain European rice production. We investigated four non‐chemical weed management strategies in the Ebro Delta in north‐eastern Spain, two in dry‐seeded rice fields and two in water‐seeded rice fields. In addition, two controls per sowing condition were included: a positive control consisting of chemical herbicides treatment and a negative control consisting of no weeding and no seeding. Mechanical weeding using a rotary harrow placed in front of the seeder was the best weeding technique for dry seeding, while 'stale seed bed' and transplanting was the best performing technique for wet seeding. Both techniques were as effective as the chemical weeding control, reducing the density of weeds and the supplementary manual weeding time needed for those weed species more abundant in Ebro Delta rice fields (i.e., Echinochloa oryzoides, Echinochloa crus‐galli, Bolboschoenus maritimus and Heteranthera reniformis). Thus, non‐chemical weeding alternatives have been proven effective for both, transplanting and dry seeding field management strategies. [ABSTRACT FROM AUTHOR]

Cover cropping plays an important role in Integrated Weed Management (IWM). Weed suppression of cover crops occurs by competition, physical barrier on the soil and allelopathy. Under favourable growing conditions, cover crops can provide similar weed suppression in the autumn‐to‐spring period as repeated stubble tillage and non‐selective herbicides. The objective of this study was to test if cover crop species with higher allelopathic potential can suppress weeds in the field with less shoot biomass than cover crop species with lower allelopathic effects. Data of cover crop shoot biomass, percentage of weed suppression in the field and reduction of weed seed germination in petri‐dish bioassays treated with cover crop extracts were analysed from 11 experiments. Weed suppression in relation to cover crop biomass was better predicted by a Weibul three‐parameter model than with the Cousens model. Raphanus sativus var. oleiferus, Sinapis alba, Fagopyrum esculentum and Phacelia tanacetifolia needed at least three‐fold more biomass than Avena strigosa for 80% weed suppression. Vicia sativa had the lowest weed reduction of only 62%. Aqueous extracts of A. strigosa had the highest inhibiting effect on weed seed germination followed by R. sativus. The lowest effect was observed for P. tanacetifolia. It is assumed that for A. strigosa allelopathy strongly contributes to weed suppression whereas for P. tanacetifolia and other cover crops, competition plays the major role for weed suppression. The model can help growers and consultants to mix cover crop species for the autumn‐to‐spring period. Under dry conditions, species such as A. strigosa can provide high weed suppression with low biomass. Under moist conditions, rapidly growing cover crops such as S. alba suppress most weeds and deliver high biomass. [ABSTRACT FROM AUTHOR]

Management of perennial weeds has become increasingly complex with the reduction of herbicide use and tillage. Their capacity to store nutrients into vegetative organs and to regenerate to establish new individuals makes them very persistent and hard to control. A key aspect for managing perennial weeds is to minimise storage reserves to reduce vegetative regeneration. For that prospect, better knowledge of the regrowth capacities from storage organs is needed. Our work focused on the mechanistic understanding of belowground regrowth dynamics from fragments of Elymus repens rhizomes by analysing the effect of source and sink factors. The effect of rhizome fragment weight (i.e., source) and the number of regrowing buds and belowground shoots (i.e., sinks) was assessed for four mechanisms: sprouting, belowground shoot elongation, belowground shoot biomass to length conversion and biomass allocation to belowground shoots versus roots. Heavier fragments contributed to faster sprouting, faster belowground shoot elongation and increased the proportion of remobilised biomass allocated to belowground shoots. Higher belowground shoot density increased the proportion of remobilised biomass allocated to belowground shoots but decreased individual elongation rate. In other words, larger reserves resulted in a better regeneration capacity and a higher number of growing belowground shoots increased the competition for reserves among them. The belowground shoot that sprouted first on a fragment grew faster and dominated the other shoots on the same fragment. Dominant belowground shoots were located toward the apical end of the fragment. These findings support the fact that tillage should aim at cutting storage organs into the smallest fragments possible to reduce regeneration capacity. This study also emphasised that belowground regrowth mechanisms are complex, and further studies should investigate other species with different types of storage organs. [ABSTRACT FROM AUTHOR]

The above‐ground community dynamics of weeds represent the soil weed seedbank in an agro‐ecosystem. Hence, understanding the seedbank will offer an idea for future weed management tactics. We aimed to determine the density of weed seedbank and emergence of major weeds in direct seeded rice (DSR) (Oryza sativa L.)—mustard (Brassica campestris L. var. yellow sarson) cropping sequence under varied tillage and herbicide combinations. The present study on weed seedbank was conducted using seedling emergence method after collecting the soils at the harvest of mustard at the completion of 2 years field experimentation. The experiment was conducted in split‐plot design with two tillage practices [zero tillage (ZT) and conventional tillage (CT)] in main plot and eight weed management practices in DSR [oxadiargyl followed by (fb) bispyribac‐sodium, penoxsulam + cyhalofop‐butyl, oxadiargyl fb penoxsulam + cyhalofop‐butyl, fenoxaprop‐p‐ethyl + ethoxysulfuron, oxadiargyl fb fenoxaprop‐p‐ethyl + ethoxysulfuron, pendimethalin fb bispyribac‐sodium, unweeded control, and weed free check] as subplot. The carry‐over effect of tillage and weed management practices were recorded in mustard crop. Seed emergence study revealed that ZT reduced the emergence of grassy weeds (by 13.7%) and total weed emergence (19.5%) in comparison to the CT (p < 0.05). However, emergence of broadleaf weeds was 24.5% higher in ZT than in CT. The higher infestation was recorded for Ludwigia parviflora (Jacq.) Raven under penoxsulam + cyhalofop‐butyl, fenoxaprop‐p‐ethyl + ethoxysulfuron, Cyperus iria (L.) under fenoxaprop‐p‐ethyl + ethoxysulfuron, and Eleusine indica (L.) Gaertn. under pendimethalin fb bispyribac‐sodium, oxadiargyl fb bispyribac‐sodium. Sole application of post‐emergence (POE) herbicide decreased the total weed emergence by 22.2%–28.1% than unweeded control (p < 0.05). Whereas, sequential application of PRE + POE herbicides decreased the total weed emergence by 32.8%–36.9% than unweeded control (p < 0.05). Notably, sedge weeds such as Cyperus iria (L.) and Fimbristylis miliacea (L.) Vahl were lower in ZT than in CT under herbicide treated plots (by 66.6%–84.3%) than unweeded control. Thus, ZT with oxadiargyl 90 g a.i. ha−1fb fenoxaprop‐p‐ethyl + ethoxysulfuron (90 + 15 g a.i. ha−1) as tank‐mix can be effectively used to lower the weed seedbank density vis‐à‐vis managing complex weed flora in DSR and rice‐mustard cropping sequence. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the efficacy of herbicides in association to control Rottboellia exaltata and Ipomoea quamoclit during pre-emergence while also to evaluate the potential impact on the sugarcane. The experimental design employed a randomized block with seven treatments and four replications. The treatments were: 1 – no herbicide application; 2 – indaziflam + sulfentrazone; 3 – indaziflam + diclosulam; 4 – indaziflam + tebuthiuron; 5 – flumioxazin + diclosulam, 6 – flumioxazin + pyroxasulfone and 7 – clomazone + sulfentrazone. The evaluated parameters were: percentage of weeds control, green coverage percentage (Canopeo® system), weed biomass (g m−2), itchgrass height, and sugarcane tiller. Several herbicide associations have been proven effective alternatives for managing itchgrass and cypressvine morningglory. The most successful treatments for itchgrass control were indaziflam + tebuthiuron (100%) and indaziflam + diclosulam (97%), whereas for cypressvine morningglory, the betters were indaziflam + sulfentrazone (97%), indaziflam + diclosulam (98%), indaziflam + tebuthiuron (97%), flumioxazin + diclosulam (94%), and clomazone + sulfentrazone (96%). All treatments reduced the weed biomass, with indaziflam + tebuthiuron being the safest option for protecting sugarcane. [ABSTRACT FROM AUTHOR]

This study describes a novel spray-on mulch material as an alternative to currently used weed control methods. The mulch material is based on renewable raw materials, mainly rapeseed oil, starch and sodium alginate. Laboratory tests were conducted to obtain a mulch material with the best possible properties. Formulations with different ingredients were prepared and tested for their material properties. The formulations were investigated for potential shrinkage tendency and heat resistance as well as water resistance. Further tests such as resistance to mould infestation and aerobic degradability according to DIN EN ISO 17556 were carried out with the formulation that performed best in the previous tests. Mould resistance was enhanced by adding sodium benzoate. In the laboratory experiment, the CO2 decomposition rate was about 30% after seven weeks. With the favouritised variant, which was found step by step through the experiments, an outdoor field test was carried out to investigate the durability under natural conditions over the vegetation period. In the field, the mulch material maintained its function for six months. In the greenhouse, the effect of the mulch material on weeds was studied. It was found that the mulch material showed a high efficiency in controlling above-ground biomass of Elymus repens, Amaranthus retroflexus, and Setaria viridis. In addition, the biomass of the roots of Amaranthus retroflexus and Elymus repens was reduced. Further studies are on the way to elucidate field suitability and the weed suppressive effect under different environmental conditions. [ABSTRACT FROM AUTHOR]

Weed communities influence the dynamics of ecosystems, particularly in disturbed environments where anthropogenic activities often result in higher pollution. Understanding the dynamics existing between native weed communities and invasive species in disturbed environments is crucial for effective management and normal ecosystem functioning. Recognising the potential resistance of native weed communities to invasion in disturbed environments can help identify suitable native plants for restoration operations. This review aims to investigate the adaptations exhibited by native and non‐native weeds that may affect invasions within disturbed environments. Factors such as ecological characteristics, altered soil conditions, and adaptations of native weed communities that potentially confer a competitive advantage relative to non‐native or invasive weeds in disturbed environments are analysed. Moreover, the roles of biotic interactions such as competition, mutualistic relationships, and allelopathy in shaping the invasion resistance of native weed communities are described. Emphasis is given to the consideration of the resistance of native weeds as a key factor in invasion dynamics that provides insights for conservation and restoration efforts in disturbed environments. Additionally, this review underscores the need for further research to unravel the underlying mechanisms and to devise targeted management strategies. These strategies aim to promote the resistance of native weed communities and mitigate the negative effects of invasive weed species in disturbed environments. By delving deeper into these insights, we can gain an understanding of the ecological dynamics within disturbed ecosystems and develop valuable insights for the management of invasive species, and to restore long‐term ecosystem sustainability. [ABSTRACT FROM AUTHOR]

Salt excretory halophytes are the major sources of phytoremediation of salt-affected soils. Cressa cretica is a widely distributed halophyte in hypersaline lands in the Cholistan Desert. Therefore, identification of key physio-anatomical traits related to phytoremediation in differently adapted C. cretica populations was focused on. Four naturally adapted ecotypes of non-succulent halophyte Cressa cretica L. form hyper-arid and saline desert Cholistan. The selected ecotypes were: Derawar Fort (DWF, ECe 20.8 dS m−1) from least saline site, Traway Wala Toba (TWT, ECe 33.2 dS m−1) and Bailah Wala Dahar (BWD, ECe 45.4 dS m−1) ecotypes were from moderately saline sites, and Pati Sir (PAS, ECe 52.4 dS m−1) was collected from the highly saline site. The natural population of this species was collected and carefully brought to the laboratory for different structural and functional traits. As a result of high salinity, Na+, Cl–, K+, and Ca2+ content significantly increased at root and shoot level. At root level, some distinctive modifications such as increased sclerification in vascular bundles, enlarged vascular bundles, metaxylem vessels, phloem region, and storage parenchyma (cortex) are pivotal for water storage under extreme arid and osmotic condition. At the stem level, enhanced sclerification in outer cortex and vascular bundles, stem cellular area, cortical proportion, metaxylem and phloem area, and at the leaf level, very prominent structural adaptations were thicker and smaller leaves with increased density of salt glands and trichomes at surface, few and large stomata, reduced cortical and mesophyll parenchyma, and narrow xylem vessels and phloem area represent their non-succulent nature. The ecotype collected from hypersaline environments was better adapted regarding growth traits, ion uptake and excretion, succulence, and phytoremediation traits. More importantly, structural and functional traits such as root length and biomass, accumulation of toxic ions along with K+ in root and shoot, accumulation of Ca2+ in shoot and Mg2+ in root, excretion of toxic ions were the highest in this ecotype. In conclusion, all these alterations strongly favor water conservation, which certainly contributes to ecotypes survival under salt-induced physiological drought. Naturally adapted salt tolerant plants provide exceptional material for exploring adaptive mechanisms they use to confront high salt concentrations. Cressa cretica is a hypersaline hyperarid desert colonizer, which was previously underexplored. In the present study, we focused on the new insight on relationship among anatomical modifications, salt accumulation and excretion and phytoremediation potential of this rare species. [ABSTRACT FROM AUTHOR]

Endophytic bacteria, recognized as eco-friendly biofertilizers, have demonstrated the potential to enhance crop growth and yield. While the plant growth-promoting effects of endophytic bacteria have been extensively studied, the impact of weed endophytes remains less explored. In this study, we aimed to isolate endophytic bacteria from native weeds and assess their plant growth-promoting abilities in rice under varying chemical fertilization. The evaluation encompassed measurements of mineral phosphate and potash solubilization, as well as indole-3-acetic acid (IAA) production activity by the selected isolates. Two promising strains, tentatively identified as Alcaligenes faecalis (BTCP01) from Eleusine indica (Goose grass) and Metabacillus indicus (BTDR03) from Cynodon dactylon (Bermuda grass) based on 16S rRNA gene phylogeny, exhibited noteworthy phosphate and potassium solubilization activity, respectively. BTCP01 demonstrated superior phosphate solubilizing activity, while BTDR03 exhibited the highest potassium (K) solubilizing activity. Both isolates synthesized IAA in the presence of L-tryptophan, with the detection of nifH and ipdC genes in their genomes. Application of isolates BTCP01 and BTDR03 through root dipping and spraying at the flowering stage significantly enhanced the agronomic performance of rice variety CV. BRRI dhan29. Notably, combining both strains with 50% of recommended N, P, and K fertilizer doses led to a substantial increase in rice grain yields compared to control plants receiving 100% of recommended doses. Taken together, our results indicate that weed endophytic bacterial strains BTCP01 and BTDR03 hold promise as biofertilizers, potentially reducing the dependency on chemical fertilizers by up to 50%, thereby fostering sustainable rice production. [ABSTRACT FROM AUTHOR]

Soybean is grown worldwide for its high protein and oil content. Weeds compete fiercely for resources, which affects soybean yields. Because of the progressive enhancement of weed resistance to herbicides and the quickly increasing cost of manual weeding, mechanical weed control is becoming the preferred method of weed control. Mechanical weed control finds it difficult to remove intra-row weeds due to the lack of rapid and precise weed/soybean detection and location technology. Rhodamine B (Rh-B) is a systemic crop compound that can be absorbed by soybeans which fluoresces under a specific excitation light. The purpose of this study is to combine systemic crop compounds and computer vision technology for the identification and localization of soybeans in the field. The fluorescence distribution properties of systemic crop compounds in soybeans and their effects on plant growth were explored. The fluorescence was mainly concentrated in soybean cotyledons treated with Rh-B. After a comparison of soybean seedlings treated with nine groups of rhodamine B solutions at different concentrations ranging from 0 to 1440 ppm, the soybeans treated with 180 ppm Rh-B for 24 h received the recommended dosage, resulting in significant fluorescence that did not affect crop growth. Increasing the Rh-B solutions reduced crop biomass, while prolonged treatment times reduced seed germination. The fluorescence produced lasted for 20 days, ensuring a stable signal in the early stages of growth. Additionally, a precise inter-row soybean plant location system based on a fluorescence imaging system with a 96.7% identification accuracy, determined on 300 datasets, was proposed. This article further confirms the potential of crop signaling technology to assist machines in achieving crop identification and localization in the field. [ABSTRACT FROM AUTHOR]

The influence of spatial resolution on classification accuracy strongly depends on the research object. With regard to unmanned aerial vehicle (UAV)-based weed mapping, contradictory results on the influence of spatial resolution have been attained so far. Thus, this study evaluates the effect of spatial resolution on the classification accuracy of weeds in a soybean field located in Belm, Lower Saxony, Germany. RGB imagery of four spatial resolutions (0.27, 0.55, 1.10, and 2.19 cm ground sampling distance) corresponding to flight altitudes of 10, 20, 40, and 80 m were assessed. Multinomial logistic regression was used to classify the study area, using both pixel- and object-based approaches. Additionally, the flight and processing times were monitored. For the purpose of an accuracy assessment, the producer's, user's, and overall accuracies as well as the F1 scores were computed and analyzed for statistical significance. Furthermore, McNemar's test was conducted to ascertain whether statistically significant differences existed between the classifications. A linear relationship between resolution and accuracy was found, with a diminishing accuracy as the resolution decreased. Pixel-based classification outperformed object-based classification across all the resolutions examined, with statistical significance (p < 0.05) for 10 and 20 m. The overall accuracies of the pixel-based approach ranged from 80 to 93 percent, while the accuracies of the object-based approach ranged from 75 to 87 percent. The most substantial drops in the weed-detection accuracy with regard to altitude occurred between 20 and 40 m for the pixel-based approach and between 10 and 20 m for the object-based approach. While the decline in accuracy was roughly linear as the flight altitude increased, the decrease in the total time required was exponential, providing guidance for the planning of future UAV-based weed-mapping missions. [ABSTRACT FROM AUTHOR]

Background and aims: The escalating issue of soil saline-alkalization poses a growing global challenge. Leymus chinensis is a perennial grass species commonly used in the establishment and renewal of artificial grasslands that is relatively tolerant of saline, alkaline, and drought conditions. Nonetheless, reduced seed setting rates limit its propagation, especially on alkali-degraded grassland. Inter-annual variations have an important effect on seed yield and germination under abiotic stress, and we therefore examined the effect of planting year on seed yield components of L. chinensis. Methods: We grew transplanted L. chinensis seedlings in pots for two (Y2), three (Y3), or four (Y4) years and collected spikes for measurement of seed yield components, including spike length, seed setting rate, grain number per spike, and thousand seed weight. We then collected seeds produced by plants from different planting years and subjected them to alkaline stress (25 mM Na2CO3) for measurement of germination percentage and seedling growth. Results: The seed setting rate of L. chinensis decreased with an increasing number of years in pot cultivation, but seed weight increased. Y2 plants had a higher seed setting rate and more grains per spike, whereas Y4 plants had a higher thousand seed weight. The effects of alkaline stress (25 mM Na2CO3) on seed germination were less pronounced for the heavier seeds produced by Y4 plants. Na2CO3 caused a 9.2% reduction in shoot length for seedlings derived from Y4 seeds but a 22.3% increase in shoot length for seedlings derived from Y3 seeds. Conclusions: Our findings demonstrate significant differences in seed yield components among three planting years of L. chinensis under pot cultivation in a finite space. Inter-annual variation in seed set may provide advantages to plants. Increased alkalinity tolerance of seed germination was observed for seeds produced in successive planting years. [ABSTRACT FROM AUTHOR]

Rice paddies are wetland ecosystems recognized as important habitats for many organisms; however, the hybridization‐related extinction risk of native plant species has not been investigated in this system so far. Eclipta L. (Compositae) is a common paddy weed in Japan; however, its genetic composition might be altered due to the hybridization between the native E. thermalis and the closely related exotic E. alba. We examined Eclipta's genetic composition using 12 microsatellite markers (612 samples collected from 109 populations) and found (i) widespread geographical distribution of E. alba in Japan, (ii) hybridization with E. thermalis, and a large number of later‐generation hybrids, and (iii) widely varying situations among regions and populations. Eclipta alba appears to have invaded an open niche in northern Japan but has not yet reached southern Japan. Both E. alba and E. thermalis were found in central Japan; however, the latter had become rare due to hybridization‐mediated processes such as competition, and demographic and genetic swamping. Notably, endogenous and exogenous selection plays an important role in the invasion of E. alba, but to varying degrees among different areas. In summary, considering the genetic variability in E. thermalis, the genetic cluster of mainland Japan is in a highly critical situation due to the invasion of E. alba. [ABSTRACT FROM AUTHOR]

Context: Seasonal variations between the rain and dry seasons are the main obstacle to agricultural productivity in tropical regions, making it essential to conserve surplus for periods of scarcity. One of the limiting factors in ensiling grasses is moisture, requiring the use of additives or withering. Using a mixture of grasses and legumes can be an alternative to balance the advantages and disadvantages of both in the ensiling process, and mata-pasto hay (MPH) can be an option. Aims: This study evaluated different forms of Tanzania grass (Megathyrsus maximum) and MPH silages, as well as silages with increasing levels of MPH. Methods: Silages of Tanzania grass and MPH in their natural form, as well as silages with increasing doses of MPH, were evaluated for nutritional value, degradability in situ. The microbiology was also evaluated. Key results: Among the types of silages, natural MPH and wilted MPH were superior to natural Tanzania grass silage. The use of MPH in Tanzania grass silages improves fermentation processes, the population of beneficial microorganisms, resulting in better nutritional value of these silages. Conclusions: Natural and wilted MPH hay silages are qualitatively better compared to natural Tanzania grass silage. Increasing doses of MPH improve the quality of the silage. A recommended dose is 30% of MPH hay. Implications: Adding MPH to silages is a way to reduce the negative impacts of this weed on pastures. However, further studies with the use of complementary additives are needed. The seasonality between the rainy and dry seasons is a challenge for tropical agriculture. This study evaluated different forms of ensiling Tanzania grass (Megathyrsus maximum) and forest pasture hay (FPH) aiming to improve the conservation and nutritional value of silages. Results showed that the use of 30% FPH improved the fermentative processes and the nutritional value of the silages. This strategy can reduce the negative impacts of weeds on pastures, although further research is needed for complementary additives. [ABSTRACT FROM AUTHOR]

Background: Regular cannabis is known to impact higher-order cognitive processes such as attention, but far less is known regarding cognitive flexibility, a component of executive function. Moreover, whether such changes are related to aberrations in the neural oscillatory dynamics serving flexibility remains poorly understood. Aims: Quantify the neural oscillatory dynamics serving cognitive flexibility by having participants complete a task-switching paradigm during magnetoencephalography (MEG). Probe whole-brain maps to identify alterations in chronic cannabis users relative to nonusers and determine how these alterations relate to the degree of cannabis use involvement. Methods: In all, 25 chronic cannabis users and 30 demographically matched nonuser controls completed neuropsychological testing, an interview regarding their substance use, a urinalysis, and a task switch paradigm during MEG. Time-frequency windows of interest were identified using a data-driven statistical approach and these were imaged using a beamformer. Whole-brain neural switch cost maps were computed by subtracting the oscillatory maps of the no-switch condition from the switch condition per participant. These were examined for group differences. Results: Cannabis users had weaker theta switch cost responses in the dorsolateral and dorsomedial prefrontal cortices, while nonusers showed the typical pattern of greater recruitment during switch relative to no switch trials. In addition, theta activity in the dorsomedial prefrontal cortex was significantly correlated with cannabis use involvement. Conclusions: Cannabis users exhibited altered theta switch cost activity compared to nonusers in prefrontal cortical regions, which are critical for cognitive flexibility. This activity scaled with cannabis use involvement, indicating a link between cannabis use and aberrant oscillatory activity underlying cognitive flexibility. [ABSTRACT FROM AUTHOR]

A key challenge in the management of populations is to quantify the impact of interventions in the face of environmental and phenotypic variability. However, accurate estimation of the effects of management and environment, in large‐scale ecological research is often limited by the expense of data collection, the inherent trade‐off between quality and quantity, and missing data.In this paper we develop a novel modelling framework, and demographically informed imputation scheme, to comprehensively account for the uncertainty generated by missing population, management, and herbicide resistance data. Using this framework and a large dataset (178 sites over 3 years) on the densities of a destructive arable weed (Alopecurus myosuroides) we investigate the effects of environment, management, and evolved herbicide resistance, on weed population dynamics.In this study we quantify the marginal effects of a suite of common management practices, including cropping, cultivation, and herbicide pressure, and evolved herbicide resistance, on weed population dynamics.Using this framework, we provide the first empirically backed demonstration that herbicide resistance is a key driver of population dynamics in arable weeds at regional scales. Whilst cultivation type had minimal impact on weed density, crop rotation, and earlier cultivation and drill dates consistently reduced infestation severity.Synthesis and applications: As we demonstrate that high herbicide resistance levels can produce extremely severe weed infestations, monitoring herbicide resistance is a priority for farmers across Western Europe. Furthermore, developing non‐chemical control methods is essential to control current weed populations, and prevent further resistance evolution. We recommend that planning interventions that centre on crop rotation and incorporate spring sewing and cultivation to provide the best reductions in weed densities. More generally, by directly accounting for missing data our framework permits the analysis of management practices with data that would otherwise be severely compromised. [ABSTRACT FROM AUTHOR]

A growing number of industrial disturbances are reclaimed with native grass species, although use of many native forbs in reclamation is limited due to low availability, high expense, poor germination, and lack of information on how to successfully establish them. Therefore, a study was conducted to assess the performance (establishment, growth, and survival) of native forbs (10 species by seeding and 12 species by transplanting) on disturbed sites planted in different seasons (spring and fall) and subjected to different types of vegetation management (mowed and unmowed). All seeded forb species established successfully, although density of most of the native forbs was very low (<20 stems/plot). Transplanted forb species established well, with 65% of seedlings surviving two growing seasons. Establishment and survival of seeded and transplanted native forbs were associated with plant competition, where forbs established well with annual weeds and less successfully with perennial weeds. Both spring seeding and transplanting increased forb establishment; and seeding and transplanting in fall versus spring produced more seed. Mowing generally had limited effects on forbs. Of the seeded species, Vicia americana, Achillea millefolium, and Ratibida columnifera consistently had the highest densities across treatments, whereas spring transplanting increased establishment of Anemone cylindrica, Gaillardia aristata, Geum triflorum, Monarda fistulosa, and Dalea purpurea. Spring‐transplanted forbs spread over a larger area than fall‐transplanted forbs. In most cases, seeding and transplanting native forbs in the spring can be more effective than in fall to reclaim disturbed sites if land management practices are used to control perennial weeds. [ABSTRACT FROM AUTHOR]

Riparian areas can be highly biodiverse and provide critical ecosystem services. However, they are frequently subject to anthropogenic impacts such as land clearing, agricultural use, and urban development. Restoration of riparian areas via revegetation commonly improves the health of waterways and surrounding areas, but vegetation outcomes are rarely assessed. Our study compared 10 to 14‐year‐old revegetation to remnant vegetation in riparian areas of south‐eastern Australia to determine if species composition, vegetation structure, and ecosystem function (plant recruitment) differed. We also assessed if the amount of surrounding native vegetation, browsers (including deer, rabbits, and macropods), or soil characteristics influenced native woody plant recruitment at revegetated sites. While native and exotic woody species richness did not differ, native woody plants were less abundant and exotic woody plants twice as abundant at revegetated sites. The ground layer of revegetated sites was dominated by weeds, whereas remnant sites largely comprised native herbaceous plants and leaf litter. Tree heights and tree canopy cover were similar in revegetated and remnant areas, although shrubs and ferns were lacking in revegetation. Native woody plant recruitment was lower at revegetated sites and was negatively associated with browser presence. Our results suggest that while revegetation may have similar species richness and tree cover as remnant areas, weeds often dominate and important structural components such as shrubs and ferns, and ecological processes such as plant recruitment, are lacking. Better consideration of all vegetation strata, reduced browsing pressure and weed control are likely to achieve better revegetation outcomes. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms by which wild bees survive in modified landscapes is important for their conservation and management as pollinators. Pollen is a critical resource for the completion of bee life cycles, so we investigated how the pollen loads carried by native bee communities change between natural forests and farms dominated by exotic crops and weeds in an agricultural region of south‐east Australia.We found that individual bees tended to carry higher proportions of exotic pollen on farms compared with forests (after accounting for whether they were captured on exotic or native flowers), and the diversity of pollen carried by bees did not differ significantly between native forest and farm sites or along native forest cover gradients. This suggests that the native bees found on farms, which are predominantly different species compared with those found in native forests, are not disadvantaged by the dominance of exotic plants in these habitats (though impacts on larval nutrition were not investigated).While some native bees carried crop pollen, others almost exclusively carried the pollen of agricultural weeds (e.g., Arctotheca and Brassica species), such that some native bee species may pollinate and benefit from crops, whereas others may only persist on farms if agricultural weeds are tolerated. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the allelopathic potential of Crotalaria spp. to control guinea grass (Panicum maximum Jacq.). Experiments were done on germination and development of P. maximum in Petri-plate Lab Bioassays with the seed exudates of germinating seeds germination water of seed and leaf extract of C. juncea and also in Pot Culture coexistence by sowing and transplantation of two test species. Among the species studied, C. juncea gave the best result to inhibit the germination of target plant, hence, it was selected for further studies. The germination results showed that the highest densities (5, 10 and 20) of C. juncea affect different stages of P. maximum. The higher the concentration of bioextract from C. juncea, the lower was development of P. maximum was decreased with doses from 25 to 100 % for its control. The greater was the density and concentration of C. juncea extracts, the greater was the decrease in germination speed, germination (%), root length, plant height and dry mass weight of P. maximum. [ABSTRACT FROM AUTHOR]

The cause of recent population declines in some farmland/hedgerow breeding bird species in the UK is related to a lack of cover and food resources in winter. In improved grassland areas some of those declines have been particularly acute and some have been shown to be related to the availability of grass and weed seed in winter. The provision of seed‐bearing crops as part of AES options has been shown to benefit some of these birds. Game crop plots sown on shooting estates for holding and driving gamebirds in autumn and winter have been shown to hold relatively high densities of farmland and wood‐edge birds during the winter. We studied breeding songbirds in hedges in a primarily improved grassland area in the SW of England where there are some large shooting estates that sow relatively large game crop plots (1–5 ha) in the landscape. In this study we found that otherwise similar hedges in terms of size and density near to those winter game crop plots, had between 1.5 and 2 times as many breeding resident songbirds per unit length the following spring compared to hedges further away from game crop plots. This was despite game management in these plots being wound down during February and in many cases, the crops themselves being removed by mid‐March. Hedges within approximately 350 m from game crop plots had more breeding birds. We discuss possible mechanisms and suggest that some passerines preferentially establish breeding territories in hedges near to game crops in late winter. We suggest how to distribute game crop plots to maximise any benefit in an improved grassland landscape. [ABSTRACT FROM AUTHOR]

In light of the environmental pollution resulting from the excessive use of chemical fertilizers, several methods, including the analysis of morphological and cultural characteristics as well as ITS rDNA sequencing, were utilized to identify the strain and evaluate its phosphate solubilizing capacity. A controlled greenhouse pot experiment was then conducted to assess the effects of the phosphate solubilizing bacteria strain Y-5 on crop growth and soil fertility. The identification results revealed that the phosphate solubilizing strain, Y-5, belongs to Pseudomonas donghuensis. Under liquid culture for 5 days, the ratio of the phosphate solubilizing ring's diameter to the colony's diameter (D/d) was 3.51. Notably, strain Y-5 exhibited exceptional phosphate solubilization efficiency, with a maximum phosphate solubilizing amount of calcium phosphate reaching 432.25 mg/L. Furthermore, the highest phosphate soluble content of lecithin was 116.37 mg/L, highlighting its robust phosphate solubilizing capacity. The pot experiment results revealed that the modified biochar of strain Y-5 effectively enhances the content of available phosphate and organic matter in soil. Additionally, the modified biochar of the Y-5 strain exerted a significant growth-promoting effect on corn seedlings. Based on the indices of maize seedling growth and soil property changes, it was determined that the optimal application ratio of Pseudomonas donghuensis modified biochar was approximately 10 g/kg. This research result significantly reduced the cost of popularizing and applying phosphate solubilizing bacteria modified biochar and served as a new agricultural material with good prospects for popularization and application, potentially contributing to the green and sustainable development of agriculture in the future. [ABSTRACT FROM AUTHOR]

Ethnoveterinary medicine is crucial in many rural areas of Pakistan, as residents in remote and marginal areas rely heavily on traditional herbal medicines to cure their domestic animals. Reactive oxygen species (ROS) formed spontaneously as by products of reactions with O2 molecules, chemically damage the organic elements of the cell such as nucleic acids, proteins, and lipids. In the current research work, the anatomical, phytochemical and antioxidant of some ethnoveterinary grasses were studied. A total of four species were collected from different villages of Hafizabad during the months of April and May 2021. The collected species were identified as Cenchrus setigerus Vahl, Diplachne fusca (L.) P. Beauv., Imperata cylinderica (L.) Raeuschel and Sporobolus coromandelianus Kunth. For the anatomical studies, stems and leaves were cut into thin sections with a microtome. The anatomical characteristics observed were a compact epidermal layer, large cortical cells, thickened sclerenchyma, central and scattered vascular bundles, a large metaxylem, a small protoxylem, a pitted phloem, and a centrally located pith. To investigate the phytochemical and antioxidant potential, the crude methanol extract was prepared by maceration and subjected to fractionation with n-hexane, petroleum ether, chloroform, methanol, and water. D. fusca showed strong scavenging activity i.e. 75.87±0.14 of DPPH at 250 µL concentration. The total antioxidant activity evaluated by phosphomolybdenum activity showed the best results in the methanol fraction of D. fusca. At a concentration of 125 µL, the methanol extracts showed maximum reducing potential of 1.20±0.06. The methanol extracts of all grasses showed maximum ferric-reducing antioxidant potential except I. cylinderica, which showed a maximum potential of 1.77±0.054 TE µM/mL in chloroform extracts. The methanol extract of I. cylinderica had the highest TPC value of 118.32±1.27 (GAE) mg/mL. This study provides experimental confirmation that grasses, when consumed, can be used as natural antioxidants and can be used to combat various diseases caused by reactive oxygen species. [ABSTRACT FROM AUTHOR]

This comprehensive review addresses the multifaceted applications and prospects of Portulaca oleracea, commonly known as purslane. While primarily considered a weed, purslane has garnered increasing interest due to its remarkable nutritional and medicinal properties. Bibliometric analysis was applied to investigate the current research regarding this plant and its effects, identifying predominant research areas. Furthermore, emerging trends and outlines of potential directions for future research were discussed. The various forms of application of purslane were presented, encompassing its use in food, medicine, agriculture, and environmental control practices. The chemical composition, highlighting biologically significant compounds and the methods employed for their extraction, identification, and separation were addressed. These compounds of interest are being incorporated into agricultural practices, food development, and health promotion. In conclusion, our analysis underscores the increasing importance of purslane as a valuable resource with diversified applications and emphasizes its growing role in the academic landscape. [ABSTRACT FROM AUTHOR]

Cannabis sativa L., previously concealed by prohibition, is now a versatile and promising plant, thanks to recent legalization, opening doors for medical research and industry growth. However, years of prohibition have left the Cannabis research community lagging behind in understanding Cannabis genetics and trait inheritance compared to other major crops. To address this gap, we conducted a comprehensive genome-wide association study (GWAS) of nine key agronomic and morphological traits, using a panel of 176 drug-type Cannabis accessions from the Canadian legal market. Utilizing high-density genotyping-by-sequencing (HD-GBS), we successfully generated dense genotyping data in Cannabis, resulting in a catalog of 800 K genetic variants, of which 282 K common variants were retained for GWAS analysis. Through GWAS analysis, we identified 18 markers significantly associated with agronomic and morphological traits. Several identified markers exert a substantial phenotypic impact, guided us to putative candidate genes that reside in high linkage-disequilibrium (LD) with the markers. These findings lay a solid foundation for an innovative cannabis research, leveraging genetic markers to inform breeding programs aimed at meeting diverse needs in the industry. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTRelative efficacy of five common weeds—of the kind that are either rooted in soil or which freely float over water—was assessed in rapid, effective and sustainable treatment of sewage at pilot plant scale in the recently developed and patented SHEFROL® bioreactors. The plants were utilized in a unit of capacity 12,000 liters/day (LPD) which, after two years of use, was enlarged to handle 40,000 LPD of sewage. It was then further expanded after an year to treat 57,000 LPD. All the five weeds, of which none has previously been tested in a pilot-scale SHEFROL, were able to foster highly efficient primary treatment (in terms of suspended and total solids) and secondary treatment (in terms of BOD and COD) to levels exceeding 85% in most cases. Additionally, the weeds also helped in achieving significant tertiary treatment. At different hydraulic retention times, and at steady state, the five weeds achieved treatment of BOD, COD, suspended solids, nitrogen, phosphorous, copper, nickel, zinc, and manganese in the ranges, 80–95, 79–91, 82–95, 61–71, 51–73, 37–43, 30–38, 39–47, and 27–35%, respectively. It all occurred in a single process step and without the use of any machine or chemical. This made the system not only simple and inexpensive to install but also to maintain. Over continuous long-term operation for four years, the system was seen to be very robust as it was able to handle wide variations in the volumes and characteristics of sewage, as well as absorb shock loads without compromising the reactor performance. The sustainability of the system can be further enhanced by upgrading it to a circular biorefinery. Energy sources in the form of volatile fatty acids (VFAs) can be extracted from the weeds removed from SHEFROL and then the weeds can be converted into organic fertilizer using high-rate vermireactors recently developed by the authors.A novel and inexpensive, yet very efficient sewage treatment system is presented.The versatility and robustness of the system has been assessed at pilot plant scale for several years.The long-term continuous studies establish the efficacy of five common weeds—not hitherto explored at pilot plant level—which can serve as the main bioagent(s) in the sewage treatment system.The system has the potential of being transformed in to a closed-loop-no-waste biorefineryA novel and inexpensive, yet very efficient sewage treatment system is presented.The versatility and robustness of the system has been assessed at pilot plant scale for several years.The long-term continuous studies establish the efficacy of five common weeds—not hitherto explored at pilot plant level—which can serve as the main bioagent(s) in the sewage treatment system.The system has the potential of being transformed in to a closed-loop-no-waste biorefinery [ABSTRACT FROM AUTHOR]

See also the Commentary on this article by Zhang et al., 242: 327–330. [ABSTRACT FROM AUTHOR]

This article is a Commentary on Hu et al. (2023), 242: 333–343. [ABSTRACT FROM AUTHOR]

Aiming at the problems such as long growth cycle of Brassia campestris L., high cost of artificial weeding, and lack of effective weeds control technology, the main local winter rape with strong resistance to cold(Tianyou No. 4) was selected as the experimental materials. Common pre-seedling herbicides and post-seedling herbicides were selected as the experimental materials, and 3 different treatment gradients were set respectively. Using clean water as control, a total of 16 different combinations were set. Field trials were conducted in 2017 and 2018 to explore the effects of pre- and post-emergence herbicides on weeds control efficiency and yield of winter rapeseed. The results showed that, the total plant control effect and the total fresh weight control effect of single pre-seedling herbicide application was 40. 63% and 51. 64%. The total plant control effect and the total fresh weight control effect of single post-seedling herbicide was 60. 94% and 50. 75%. The total plant control effect and the total fresh weight control effect of combined application was 62. 33% and 57. 23%. Compared with the pre-seedling herbicide application alone, the total plant control effect and fresh weight control effect of co-application were increased by 21. 70 and 5. 59 percentage points, respectively. Compared with the post-seedling herbicide application alone, the total plant control effect and fresh weight control effect of co-application were increased by 1. 39 and 6. 48 percentage points, respectively. In terms of yield, the average grain yield of sole pre-herbicide increased by 61. 91% with 642. 32 kg/hm² higher than the control. Similarly, average yield of sole post-herbicide increased by 59. 41% with 616. 42 kg/hm² higher than the control, and co-application increased by 35. 52% which was 368. 52 kg/hm² higher than the control. The highest yield of sole and co-application treatments were R3O0 and R3O2 which significantly increased by 108. 22% with 1 122. 78 kg/hm² added and increased by 86. 43% with 896. 78 kg/hm² higher than the control, respectively. Therefore, according to weed density in the field of winter rape, the application of pre-seedling herbicide R3 alone or R3 combined with post-seedling herbicide O2 could be selected to achieve the most efficient weed control effect and the most significant increase in rapeseed yield. [ABSTRACT FROM AUTHOR]

Transitioning to low‐input agricultural systems such as organic farming has been acknowledged as a way to mitigate negative effects of agriculture on biodiversity. However, the speed, magnitude and context dependence of biodiversity recovery after converting to organic farming remain uncertain. In this study, we explored the response of plant communities to time since transition to organic farming in a variety of production contexts. Using a spatially replicated space‐for‐time substitution design, we surveyed plant communities in small‐grain cereal and ley fields in conventional and organic farms, distributed along independent gradients of time since transition to organic farming and proportion of seminatural grasslands in the landscapes. We selected a set of response traits to explore the mechanism of potential time lag in that response to conversion. These traits were selected to characterize the sensitivity of plant species to agricultural inputs and their ability to respond swiftly to environmental changes. We found an increase in plant species richness and evenness in cereal fields with increasing time since transition to organic farming, and a similar but less pronounced pattern in leys. After 30 years of continuous organic farming, organic cereal fields harboured more than twice the number of plant species than newly converted fields. Importantly, we found that the dependence on insect pollination, sensitivity to herbicides and dispersal capacity of plants modulated the effects of time since transition on plant communities in cereal fields. This suggests that both management and biotic interactions shape plant community structure in response to organic practices over time. Policy implications. Our study highlights that benefits of organic farming for plant diversity are likely to take decades to become substantial after conversion. We found this slow recovery of plant communities to be driven by both the gradual improvement of habitat quality after conversion and species' dispersal limitation. Assessments of biodiversity benefits of organic farming should therefore consider this time delay to avoid underestimating its environmental performance. Farmers should also be supported during this ecological transitional phase during which yield‐enhancing ecosystem services reliant on plant diversity might build up. [ABSTRACT FROM AUTHOR]

The holo-parasitic weed Orobanche crenata Forrsk. is a threat to economically important legumes and vegetables in Mediterranean countries, including Egypt. The crenate broomrape attacks several wild and cultivated plant species, and documentation of new hosts of the parasite is always required. To the best of our knowledge, this study is the first report of parasitism of the crenate broomrape on two ornamental species, Arctotis fastuosa Jacq. and Callistephus chinensis (L.) Nees. (Asteraceae). We also recorded for the first time its parasitism on the wild weeds (Ammi majus L., Lactuca serriola L., and Melilotus indicus (L.) All.) and the cultivated plant species (Carthamus tinctorius L. and Tropaeolum majus L.) from Egypt. The occurrence of O. crenata parasitism was confirmed by the attachment of its haustoria to the roots of host plants. The incidence of crenate broomrape disease was estimated for the seven species. The study also provides a morphological description of the polymorphic O. crenata on the samples from Egypt and determines the most useful characteristics for its easier identification in the field. [ABSTRACT FROM AUTHOR]

The fungus, Fusarium lateritium Nees ex Fr. (FL), has shown potential as a bioherbicide for velvetleaf (Abutilon theophrasti Medik.) control. However, to achieve optimal infection and weed mortality, bioherbicide applications must be applied to weeds that are in the cotyledonary growth stage, followed by a dew treatment of at least 16 h. Greenhouse and field experiments were established to discover possible synergistic disease interactions with a phenoxy herbicide to improve the bioherbicidal potential of this fungus, and to mitigate some of the physical and environmental restrictions that limit the utility of this fungus as a bioherbicide. In greenhouse experiments, mortalities of 94% and 94% were recorded from sequential applications of 2,4-DB [4-(2,4-dichlorophenoxy)butyric acid] (0.02 kg ae ha−1) followed by FL (1.5 × 106 spores ml−1) at 5 min or 7 days after herbicide treatment. Velvetleaf plants in the fifth-to-seventh leaf growth stage were infected and killed with < 8 hrs. of dew. Similar results occurred under field conditions. Infection and weed control were inhibited by tank mixtures of 2,4-DB and FL, and by sequential applications of FL followed by 2,4-DB. These results suggest that timely applications of 2,4-DB followed by F. lateritium may provide effective control of velvetleaf. [ABSTRACT FROM AUTHOR]

Background: The field experiment was conducted at the Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirappalli, Tamil Nadu during rabi, 2022-2023 to study the influence of spacing and weed management practices on growth characters, nutrient removal by weeds and nutrient uptake of direct seeded rice (DSR). Methods: The field experiment was laid out in split plot design with three replications. The main plots were spacing of 20 15 cm, 20 × 20 cm and 25 × 25 cm. Sub plots were assigned with weed management practices viz., pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Cono weeding on 20 DAS + hand weeding (HW) on 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Cono weeding on 20 DAS and 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS, Pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Hand weeding on 40 DAS, Hand weeding at 20 and 40 DAS and unweeded control. Result: The results indicated that the highest growth attributes, higher nutrient uptake of nitrogen, phosphorous and potassium under DSR and were significantly improved by spacing 20 × 20 cm along with pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS. This was on par with pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Hand weeding on 40 DAS and hand weeding on 20 and 40 DAS. Similarly lower nutrient removal by weeds were registered under 20 × 15 cm spacing along with pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + cono weeding on 40 DAS. The interaction of spacing 20 × 20 cm and pyrazosulfuron ethyl 10% WP at 20 g a.i ha-1 on 3 DAS as PE + Bispyribac sodium 10% SC at 25 g a.i ha-1 on 20 DAS as PoE + Cono weeding on 40 DAS significantly increased the growth attributes such as plant height, dry matter production and total numbers of tillers and significantly lowered the nutrient removal by weeds. [ABSTRACT FROM AUTHOR]

Background: Weeds are the key pest, which reduce crop productivity. Direct-seeded rice is very prone to early-stage weed infestation during initial crop development. Cultural and mechanical methods are difficult due to unavailability of labour and poor work efficiency. Hence, use of herbicides is an effective method for timely weed control. However, the efficacy of agrochemicals depends on the efficiency of spraying equipment. Conventional knapsack sprayers are used most often to spray herbicides but they are highly time-consuming, labour intensive and labour drudgery practices. Hence, the current experiment was aimed to study the efficiency of unmanned aerial vehicles (UAVs) on weed management. Methods: A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore during summer, 2022 to evaluate the efficacy of UAV-based herbicide application in direct-seeded rice. The study comprised of five weed management treatments such as pre emergence application of pretilachlor with safener and pyrazosulfuron through both UAV and knapsack sprayer and unweeded check as control. The experimental plot was laid out in a randomized block design with four replications. Result: The experimental findings showed that the application of pre-emergence pretilachlor significantly reduced the density and dry weight of grasses, sedges and broad leaved weeds in knapsack application. Moreover, it was found on par with UAV application of same herbicide without any phytotoxicity to rice seedlings. From the experiment, the application of pre-emergence pretilachlor through UAV is found to be more effective for timely weed control during early stages in direct-seeded rice, which reduce the labour intensity and drudgery than knapsack application. [ABSTRACT FROM AUTHOR]

Till a few decades ago, chemical pesticides proved to be a boon in reviving our country from the food crisis, but we soon came to know that these chemicals also have side effects, which is causing great harm to the living being and environment. To avoid these side effects the best substitutes are biopesticides, but the use of biopesticides is much less as compared to chemical pesticides. There are many reason for this, one of the main reason is the lack of their resources, so it is necessary that new resources of the biopesticides should be discovered. For this review article we have collected research papers from 2010 to 2022. All these research papers collected are based on antimicrobial activities, chemical analysis etc. of weed plants extracts. We have tabulated some important information related to the weed plants used in these research articles. All research papers gathered from the authentic sources. Through this review article, we want to highlight "Weed Plants" as a resource for biopesticides formulation. After reviewing all the selected research articles, it comes to the fore that weed plants have the potential to be a good source for biopesticides formulation in future. [ABSTRACT FROM AUTHOR]

The increasing prevalence of herbicide-resistant weeds has led to a search for new herbicides that target plant growth processes differing from those targeted by current herbicides. In recent years, some studies have explored the use of natural compounds from microorganisms as potential new herbicides. We previously demonstrated that tenuazonic acid (TeA) from the phytopathogenic fungus Stemphylium loti inhibits the plant plasma membrane (PM) H+-ATPase, representing a new target for herbicides. In this study, we further investigated the mechanism by which TeA inhibits PM H+-ATPase and the effect of the toxin on plant growth using Arabidopsis thaliana. We also studied the biochemical effects of TeA on the PM H+-ATPases from spinach (Spinacia oleracea) and A. thaliana (AHA2) by examining PM H+-ATPase activity under different conditions and in different mutants. Treatment with 200 μM TeA-induced cell necrosis in larger plants and treatment with 10 μM TeA almost completely inhibited cell elongation and root growth in seedlings. We show that the isoleucine backbone of TeA is essential for inhibiting the ATPase activity of the PM H+-ATPase. Additionally, this inhibition depends on the C-terminal domain of AHA2, and TeA binding to PM H+-ATPase requires the Regulatory Region I of the C-terminal domain in AHA2. TeA likely has a higher binding affinity toward PM H+-ATPase than the phytotoxin fusicoccin. Finally, our findings show that TeA retains the H+-ATPase in an inhibited state, suggesting that it could act as a lead compound for creating new herbicides targeting the PM H+-ATPase. [ABSTRACT FROM AUTHOR]

Weed detection plays a crucial role in enhancing cotton agricultural productivity. However, the detection process is subject to challenges such as target scale diversity and loss of leaf symmetry due to leaf shading. Hence, this research presents an enhanced model, EY8-MFEM, for detecting weeds in cotton fields. Firstly, the ALGA module is proposed, which combines the local and global information of feature maps through weighting operations to better focus on the spatial information of feature maps. Following this, the C2F-ALGA module was developed to augment the feature extraction capability of the underlying backbone network. Secondly, the MDPM module is proposed to generate attention matrices by capturing the horizontal and vertical information of feature maps, reducing duplicate information in the feature maps. Finally, we will replace the upsampling module of YOLOv8 with the CARAFE module to provide better upsampling performance. Extensive experiments on two publicly available datasets showed that the F1, mAP50 and mAP75 metrics improved by 1.2%, 5.1%, 2.9% and 3.8%, 1.3%, 2.2%, respectively, compared to the baseline model. This study showcases the algorithm's potential for practical applications in weed detection within cotton fields, promoting the significant development of artificial intelligence in the field of agriculture. [ABSTRACT FROM AUTHOR]

Parthenium hysterophorus L. (Asteraceae), commonly known as famine weed in South Africa, is one of the most invasive weeds worldwide, accountable for losses to biodiversity, agriculture, the economy, and the health of livestock and human beings. The spread of this weed is not easy to manage or reverse. With globalization, trade, and human movement, it will continue to spread, allowing its range to expand into new areas. This weed has serious adverse effects on rangeland and agricultural crop production. Because of its unique characteristics, its invasiveness and competitive success rates are attributed to its high reproductive ability, fast growth rate, tolerance to environmental stresses, climate change adaptability, allelopathic potential, and unpalatability to animals. Parthenium hysterophorus dominates diverse habitats by spreading quickly as a contaminant of grain and other crop products and through farm machinery. It is widely distributed and has become problematic in various countries, including South Africa. It has successfully invaded several provinces in the country since its introduction in 1880. Since plant invasions are not universal, this study aimed to review research that has been conducted on the aggressive weed P. hysterophorus to understand the ecological characteristics that enable its successful establishment, the economic costs associated with its detrimental impacts, and to briefly assess knowledge gaps to improve its management strategies. [ABSTRACT FROM AUTHOR]

Soy is Brazil's main commodity, and due to its importance, farmers have adopted several technological innovations, such as light supplementation, to increase grain productivity and quality. However, the use of artificial light can interfere with weed dynamics and herbicide efficiency. The objective of this work was to evaluate the effect of herbicides on weed control and qualitative and quantitative attributes of soybeans grown under light supplementation. A field experiment was set up in the city of Monte Carmelo, MG, Brazil. The treatments were distributed in plots mounted under a central pivot in two environments: with light supplementation (LED panels) and without light supplementation. The treatments were distributed across four blocks, and plots were subdivided in space. The herbicides used were glyphosate, diclosulam and glyphosate, s-metolachlor and glyphosate, fomesafen + clethodim, flumioxazin + clethodim. The variables analyzed were the number of weeds, biomass, and control; chlorophyll levels; initial fluorescence; ratio of variable fluorescence to maximum fluorescence; and soybean electron transport rate—indicators of soybean yield. Light supplementation increases the density and biomass of weeds and impairs the effectiveness of herbicides. However, light supplementation with LED panels installed on the central irrigation pivot promotes increased productivity and improvements in the quantitative and qualitative parameters of soybeans. Due to these benefits, light supplementation can be considered advantageous for irrigated soybean production. [ABSTRACT FROM AUTHOR]

This paper focuses on the weed species Echinochloa crus-galli, commonly known as barnyardgrass, which is a persistent threat to crop yield and quality, especially in maize (Zea mays) cultivation. It is one of the most problematic weeds in agricultural fields due to its aggressive growth, adaptability to different environmental conditions and prolific seed production. The incidence of Echinochloa crus-galli in maize fields has increased in recent years. This study aims to provide a comprehensive understanding of the characteristics and behavior of Echinochloa crus-galli, and to suggest effective measures to control it. This research on sweetcorn was conducted from 1992 to 2019 at the Research and Education Center Gorzyń, Złotniki branch, which belongs to the Poznań University of Life Sciences. The evaluation of weed infestation was carried out in experiments focusing on chemical weed control in maize. The experiments were designed as a one-factor randomised block design with four field replications. The condition and the degree of weed infestation (number of weeds and fresh weight of weeds) in the control plots was assessed on an annual basis at the end of June and in July. The aim of the study was to evaluate the dynamic changes in the status and extent of barnyardgrass (Echinochloa crus-galli) infestation in maize grown after various other crops in the Wielkopolska region, with a focus on the weather conditions. The study found that barnyardgrass was most likely to occur when maize was sown after winter wheat in a dry and warm year, and least likely when maize was grown in rotation after winter wheat in a cold year with average rainfall. The proportion of barnyardgrass weed mass in the total weed mass was significantly lower after winter rye than after winter wheat, winter oilseed rape and winter triticale. Further research into the biology and ecology of barnyardgrass is key to effectively controlling this weed and safeguarding sweetcorn yields. [ABSTRACT FROM AUTHOR]

Environmental benefits can be achieved by organic farming systems; however, weed pressure and timely crop nutrition remain important drawbacks for many field crops. Agroecological practices, such as double cropping (e.g., intercropping and relay cropping), using forage legume species can provide nitrogen (N) to the companion crop through biological N fixation and tackle weed issues by competing for light, water and land. The present study investigated the effect of intercropping (IC) and relay-cropping (RC) systems of durum wheat (Triticum turgidum subsp. durum (Desf.) Husn) and forage legumes (Trifolium subterraneum L., Medicago polymorpha L., and Lotus corniculatus L.) by varying organic N fertilization with the aim to reduce N-requirement and weed pressure and increase wheat grain yield and grain protein content in Mediterranean organic farming systems. N fertilizer significantly improved wheat grain yield and grain protein, while a null effect on legume and weed biomass yields was found. Double cropping (T. durum-M. polymorpha, and T. durum-L. corniculatus) enhanced wheat grain yield as compared to the control and the T. durum-T. subterraneum. IC significantly improved legume yield, grain protein and the land equivalent ratio (LER) and reduced weed dry biomass as compared with the RC and the control. Among legume species, T. subterraneum outperformed the others and was less affected by the wheat's competitive performance. Nonetheless, M. polymorpha was as effective as T. subterraneum in controlling weeds. Weed dry biomass was linearly reduced by increasing legume yield; the relationship improved by cumulating wheat grain yield to legume yield. Overall, this study indicated that double cropping, especially IC, can be a suitable agroecological practice to tackle weed issues and reduce N-requirement in Mediterranean organic cereal-based systems. [ABSTRACT FROM AUTHOR]

Navua sedge (Cyperus aromaticus), a perennial plant native to Africa, poses a significant weed concern due to its capacity for seed and rhizome fragment dissemination. Infestations can diminish pasture carrying capacity, displacing desirable species. Despite the burgeoning interest in integrated weed management strategies, information regarding the efficacy of competitive interactions with other pasture species for Navua sedge management remains limited. A pot trial investigated the competitive abilities of 14 diverse broadleaf and grass pasture species. The results indicated a range of the reduction in Navua sedge dry biomass from 6% to 98% across these species. Subsequently, three broadleaf species—burgundy bean (Macroptilium bracteatum), cowpea (Vigna unguiculata), and lablab (Lablab purpureus), and three grass species—Gatton panic (Megathyrsus maximus), Rhodes grass (Chloris gayana), and signal grass (Urochloa decumbens) were chosen for a follow-up pot trial based on their superior dry biomass performance. These six species were planted at three varying densities (44, 88, and 176 plants/m2) surrounding a Navua sedge plant. Among the grass pasture species, Gatton panic and Rhodes grass exhibited high competitiveness, resulting in a minimum decrease of 86% and 99%, respectively, in Navua sedge dry biomass. Regarding the broadleaf species, lablab displayed the highest competitiveness, causing a minimum decrease of 99% in Navua sedge dry biomass. This study highlights the increasing efficacy of crop competition in suppressing weed growth and seed production, with the most significant suppression observed at a density of 176 plants/m2. [ABSTRACT FROM AUTHOR]

Weed infestation has seriously affected the yield and quality of rapeseed, which is a globally significant oil crop. While the application of chemical herbicides in agriculture has greatly boosted agricultural efficiency and crop yield, it has also unfortunately led to escalating environmental pollution and the emergence of herbicide-resistant weeds. The ptxD gene, originating from bacteria, encodes the phosphite dehydrogenase enzyme that is responsible for converting phosphite (Phi) into orthophosphate (Pi). Phi remains unusable by plants and most microorganisms, but upon its conversion into Pi, it becomes a viable nutrient source for plants. This unique function of the ptxD gene offers promising avenues for the development of innovative weed control technologies. We tested the Phi tolerance of weeds and ptxD-expressing rapeseed (Brassica napus) through greenhouse experiments in rapeseed fields. The results revealed that a Phi concentration of 200 mg·kg of soil−1 inhibited the growth of all weeds in the rapeseed fields, while the ptxD-expressing rapeseed exhibited robust tolerance to this concentration of Phi. In field experiments, the application of 60 g·m−2 of Phi allowed the ptxD-expressing rapeseed to grow normally, while the weeds grew slowly due to phosphorus deficiency, resulting in the rapeseed having a strong competitive advantage over the weeds. The leaves of the transgenic rapeseed plants covered gaps in the field as they grew, further inhibiting weed growth and completely eliminating their harm due to shading effects. The combination of ptxD-expressing rapeseed and the application of phosphite offers a sustainable alternative to herbicides for weed management in rapeseed fields. [ABSTRACT FROM AUTHOR]

The plant growth regulator gibberellic acid (GA) and the herbicide glyphosate were examined for their possible interactions with growth and phenolic metabolism in soybean [Glycine max (L.) Merr. Cv. Hill] seedlings. GA caused increases in phenylalanine ammonia-lyase activity (PAL) (per axis basis) above those of the control seedling levels 48 h after treatment in light-grown seedlings. This effect increased to two-fold greater than control levels by 72 and 96 h after treatment. In dark-grown plants, GA had no effect on PAL levels at 24 h, reduced levels at 48 and 72 h, and increased PAL at 96 h. Early studies in our lab reported that glyphosate increased PAL levels, and also reduced hydroxyphenolic compound accumulation in both light- and dark-grown soybean seedlings. Treatments of GA plus glyphosate caused additive increases in PAL activity in light-grown seedlings, but GA lowered glyphosate's increase in PAL levels at 48–96 h after treatment in dark-grown seedlings. GA had little effect on hydroxyphenolic compound levels in either light- or dark-grown seedlings. GA treatment alone did not significantly affect root elongation, but stimulated hypocotyl and epicotyl elongation and caused marginal reversal of glyphosate inhibition of elongation in roots, hypocotyls, and epicotyls in light-grown plants. These results show some differential effects of GA and glyphosate on growth and phenolic metabolism, and their interactions that are dependent on plants grown in light or darkness. [ABSTRACT FROM AUTHOR]