The potential of plant allelochemicals to control Parthenium hysterophorus weed

Introduction: Parthenium hysterophorus has become a huge problem throughout the world and is menacingly threatening the agriculture and environment. The existing methods for controlling or eradicating P. hysterophorus weed have their own limitations, that is, physical methods are very laborious, costly and ineffective in long term; chemical methods are costly and less environmental friendly and biological methods are not appropriate on large scale. The compost from Parthenium weed can be prepared to recycle the nutrients that are sucked by undesired weed from the soil. Presently, the available methods take a long time in preparing Parthenium compost, while the shorter methods are mostly less ecofriendly. In the present work, a method and recipe have been developed for preparing compost of Parthenium weed in comparatively less time (60 days only) and that too, in an ecofriendly manner; and it has been named as Vishishta composting. The term ‘Vishishta’ is a Hindi word, which means ‘something special’. Materials and Methods: In the present experiment, Parthenium weed was composted using rock phosphate, Trichoderma viride fungi culture powder and different organic wastes such as cow dung, sawdust, cow dung ash, dried fallen leaves and wheat straw in a duration of 60 days using the method of Vishishta composting. Results: The P. hysterophorus compost contains more nitrogen, phosphorus and potassium and other nutrients than farmyard manure. Overall status of the nutrients as-prepared compost is appreciable. Conclusion: In the present experiment, a method and recipe have been developed for composting Parthenium weed in shortest duration as compared to earlier methods available till date.

The alarming use of fossil fuel based plastics causing hazardous environmental impact has drawn attention towards alternative sources. Therefore, the present study aims to utilize Parthenium hysterophorus for the production of bioplastic films and illustrates its biodegradability. A rapid biodegradable bioplastic films were synthesized using cellulose acetate (CA) prepared from Parthenium hysterophorus weed by incorporating different concentrations of polyethylene glycol 600 (PEG600) ranging from 0 to 50% w/v (BP00, BP10, BP20, BP30, BP40 and BP50) as plasticizer. The films were evaluated based on their physicochemical and mechanical properties. The highest tensile strength and Young's modulus of 11.5 ± 0.23 MPa and 170 ± 0.89 MPa, respectively have been observed for the BP10. The highest elongation at break of 9.13 ± 0.12% was exhibited by BP40. The functional groups of the plasticized and unplasticized films were characterized using Fourier transform infrared spectroscopy (FTIR). The bioplastic film BP50 exhibits highest relative crystallinity of 21.27% determined by X-ray diffraction analysis (XRD). All the bioplastic films exhibit a good thermal stability and shows three degradation stages in Thermogravimetric analysis (TGA). The bioplastic films are 69.29% biodegradable in natural conditions in 45 days, while 70.29% and 83.57% degradation are observed under composting and laboratory condition, respectively. Hence, the bioplastic films prepared from Parthenium hysterophorus by incorporating PEG600 can be a potential substitute for petroleum based plastics.

The Asteraceae family of plants, which has 16,000-17,000 genera and 24,000-30000 species, is diverse and widely spread, notably in the tropics and subtropics. Asteraceae has capitula head bracket traits that are unique to this genus of plants. This study's goal was to identify the micro-morphological makeup of the trichomes in Parthenium hysterophorus L. Invasive weed Parthenium hysterophorus L. is erect, short-lived fast-growing plant is found in hot areas and is known for its luxuriant growth. As the stem attains maturity, becomes harder. Mature stems are greenish and coated in tiny, soft hairs called hirustles. Later leaves are simple and deeply pinnatifid, while early leaves create a rosette habitat. Hundreds of tiny flower heads, or capitulum, are arranged in clusters at the apex of the branches. Trichomes are epidermal appendages that are frequently seen on the leaves, stems, and fruits of plants. There are two types of trichomes: glandular and non-glandular. The immature leaves and stem of Parthenium hysterophorus L. were cut into slices, the layers were removed, and the specimen was examined at X4, X10, X40, and X100 magnifications under light microscope. The sample was taken from the stem, which was located one to three centimeters from the tip. 14 different types of trichomes, including cylindrical, moniliform, simple uniseriate, non-glandular sessile, and palate types of glandular trichomes, are observed on the leaves, petiole, and stem of Parthenium hysterophorus L. These trichomes are primarily identified based on their structural differences. Trichomes are an important taxonomic tool for differentiating between species and genera. In respect to aridity, the study presents several new features that give future taxonomists a basic understanding of trichome diversity.

ABSTRACTParthenium weed (Parthenium hysterophorus L.) is an emerging weed species in direct-seeded aerobic systems of rice production. This two-year field study was conducted to evaluate the effect of five different densities (0, 5, 10, 15 and 20 plants m−2) of parthenium weed on rice yield and yield-related attributes. Parthenium weed produced ca. 38 to 178% higher biomass at its densities of 10 to 20 plants m−2 as compared to the lowest density of 5 plants m−2. The paddy yield and yield-related attributes were negatively affected with an increase in the parthenium weed density. In both years, the highest reductions in number of rice panicles (14 to 17%), panicle length (10 to 11%), number of grains per panicle (11 to 18%), 1000-grain weight (8 to 21%) and paddy yield (30 to 35%) were recorded at the highest parthenium weed density (20 plants m−2) tested. However, the lower densities of 5 to 15 parthenium weed plants m−2 also caused 11 to 24% and 12 to 26% losses in paddy yield during the years 2016 and 2017, respectively. Therefore, this weed species should be controlled below the density of 5 plants m−2 to avoid the substantial yield losses (over 15%) in direct-seeded rice.

Discharging volumes of leather tanneries’ wastewater into the environment without proper treatment is causing severe environmental and public health problems. Therefore, this research aimed to remove chromium ion from tannery wastewater through the adsorption of activated carbon produced from the weed Parthenium hysterophorus. The activated carbon was characterized using proximate analysis, scanning electron microscope, Fourier transforms infrared spectroscopy and an iodine test. Full factorial experimental design of 24 was employed with four factors at two levels pH (2 and 6), contact time (45 and 90 min), initial chromium concentration (40 and 100 mg/L) and adsorbent dosage (9 g/L and 90 g/L), which resulted in 16 experimental runs. The average tannery effluent characteristics were described in terms of Five days biochemical oxygen demand: 1472.00 ± 9.300 mg/L; chemical oxygen demand: 1800.00 ± 50.00 mg/L; total solids: 29,000.00 ± 1000.00; temperature: 21.50 ± 2.01 °C; electrical conductivity (EC): 29.20 ± 1.60 mS/cm and pH: 4.30 ± 0.71. The mechanism of adsorption was tested by the Langmuir and Freundlich isothermal models. Maximum chromium removal of 90% was recorded at the optimum point of pH 2, contact time 90 min and adsorbent dose 90 g/L at initial chromium concentration 100 mg/L. Similarly, the treatment of the real tannery wastewater treatment was performed at the optimum point, which resulted in 89% chromium removal. Experimental data were best fitted with the Freundlich model at the adsorptive capacity 24.8 mg/g. This indicates that the application of this activated carbon for tannery wastewater treatment may be scaled up to mitigate industrial effluent pollution challenges, but detailed investigations of the adsorbent properties remain to be studied.

Parthenium hysterophorus L. (Asteraceae) is an aggressive annual herbaceous weed which causes severe yield losses on a global scale. However, the precise impact of this weed in several countries is not yet known. To assess the impact of P. hysterophorus on maize crop losses in Pakistan, a 2 year field experiment was carried out at the CABI Rawalpindi campus in 2019 and 2020. Yield was measured on maize plants planted along with different densities (0, 1, 2, 4, 8, and 16 plants per m2) of P. hysterophorus. The trial was laid in a randomized complete block design with five replicates per density each year. The highest maize seed yield was obtained in weed-free plots (4256.5 ± 118 kg ha−1), while maize yield at weed infestation levels of 1, 2, 4, 8 and 16 plants m−2 was reduced by 14, 22, 29, 38 and 46%, respectively, compared to weed free plots. In the light of these findings, to reduce yield losses to non-significant levels it is proposed to reduce P. hysterophorus densities below 2 plants per m2 in maize fields.

Polyketides are a vital group of secondary metabolites comprising of antifungal, antibacterial as well as anticancer agents. The multifunctional enzymes responsible for the biosynthesis of these secondary metabolites are polyketide synthases (PKS) in which polyketide synthases type I (PKS-I) is mainly responsible for highly assorted group of metabolites with substantial medical importance. In this study molecular screening was done using six sets of degenerate primers to determine the presence of PKS-I gene cluster in endophytic Streptomyces isolated from the weed Parthenium hysterophorus L. A total of 40 endophytes were isolated and identified by morphological, biochemical and physiological characterization as belonging to the genus Streptomyces. The 16S rRNAgene sequencing of the selected isolates exhibited maximum similarity with different species of Streptomyces such as Streptomyces rochei (99%), Streptomyces litmocidini (99%), Streptomyces enissocaesili (99%), Streptomyces djakartensis (99%), Streptomyces olivaceus (99%), Streptomyces spp. (99%), Streptomyces plicatus (99%), Streptomyces geysiriensis (99%) and Streptomyces vinaceusdrappus (99%). The molecular screening revealed the presence of PKS-I gene with a PCR amplification products of size ∼300 bps, ∼320 bps and ∼700 bps in the isolates RT-13, RT-43, RT-47, RT-49, RT-54, RT-56, RT-57, RT-58, RT-59, RT-61 and RT-65 through all the six sets of primers used. To the best of our understanding no previous study has been carried out reporting the molecular screening of PKS-I genes in endophytic Streptomyces from Parthenium hysterophorus L. The results provide an insight into an unexplored environment containing endophytic Streptomyces harboring the polyketide synthases gene which if further investigated may lead to a new source of antimicrobial agents.

Two sets of field experiments were conducted at two sites (lowland and intermediate altitude) for 2 years in eastern Ethiopia to determine the influence of parthenium weed ( Parthenium hysterophorus ) density and duration of competition on grain yield of sorghum. In the first set of experiments, target weed densities of 0, 3, 7, 13, 27, 53 and 100 plants m -2 were used. Yield loss was severely affected by parthenium weed density, peaking at 97% at the lowland site in 2000. At this site, even very low density (e.g. three plants m -2 ) resulted in a high yield loss (69%). Owing to differences between sites and years, however, it was not possible to specify meaningfully the threshold densities for weeding. In the critical weed-free period experiments, four parthenium weed-infested and four weed-free periods from emergence to harvesting of sorghum were maintained by hand hoeing. The critical periods for weed control, i.e. the period over which weeding had the greatest benefit on yield, were 19 - 69 and 40 - 57 days from emergence of sorghum in 1999 and 2000, respectively, at the intermediate altitude (assuming an acceptable loss of 10%). In the lowland, however, it ranged directly from emergence to 61 and 66 days, indicating more severe competition at this site. The substantial variation in yield and yield loss between sites and years illustrates the problems of attempting to give well-established, accurate recommendations for threshold densities and critical periods in small-scale, rain-fed agriculture.

The weed Parthenium hysterophorus is an invasive, ubiquitous and significantly threatens agricultural productivity and biodiversity. This study explored the potential of allelopathy for its impact by investigating the effects of aqueous extracts from 31 plant species on seed germination of parthenium. The study revealed that all the 31 plant species adversely affected the germination of Parthenium seed. Leaf extract of Azadirachta indica, Cassia tora, Mentha arvensis, and Xanthium strumarium caused 100% inhibition of seed germination within7 days and did not allow further seed germination. Inhibitory effect of some plant species were persistent on germination of parthenium seed upto 15 days. Minimum inhibition in seed germination was recorded in extract of Achyranthes aspera i.e. 24.13%.

Parthenium hysterophorus weeds are one of the major problems in almost all types of agricultural lands, forest lands, pastures, farmlands and disturbed land including roadsides. It is also responsible for health problems in human and animals besides loss to agriculture and ecosystems. It causes allergic respiratory problems, contact dermatitis and mutagenicity. The main strategy of Parthenium control is the use of chemical herbicides. The increasing side effects of chemical herbicide and growing resistance against them in weeds have attracted the attention of researchers to search for some novel herbicidal compounds from natural sources. A significant barrier in the mycoherbicide metabolites production is the development of an economically viable fermentation process. The production of these compounds is largely affected by certain parameters like pH, temperature, incubation days and media constituents etc. Adjustment of these parameters up to optimum level leads to maximum production of mycoherbicidal compounds. Therefore, the purpose of this study was to standardize physiochemical conditions (Nutrient media, pH, Temperature, and Incubation periods) for maximum production of mycoherbicidal metabolites from phytopathogenic fungi Fusarium sp. FGCCW#16 isolated from Parthenium hysterophorus weed. Fusarium sp FGCCW#16 grew well and produced optimum mycoherbicidal metabolites in Richard’s broth medium at 25 to 28°C on the 21 studay of the incubation. The optimal growth, however, was obtained at pH 6. The results of this investigation indicated that cultural conditions like culture media as well as physical factors such as temperature, pH and incubation period greatly affected the growth and production of mycoherbicidal metabolites by Fusarium sp FGCCW#16.

This study was undertaken to investigate the herbicidal activity of mango (Mangifera indica L.) leaves against parthenium weed (Parthenium hysterophorus L.). The aqueous leaf extract at 15% concentration (on fresh weight basis) significantly reduced germination, shoot length and the shoot and root biomasses of parthenium seedlings. In a leaf residue incorporation pot trial, 2% residue incorporation treatment significantly suppressed the root and shoot biomasses of parthenium, while a 5% residue treatment completely stopped the growth of the weed. Five flavonoids, namely (−)-epicatechin-3-O-β-glucopyranoside (1), 5-hydroxy-3-(4-hydroxyphenyl)pyrano[3,2-g]chromene-4(8H)-one (2), 6-(p-hydroxybenzyl)taxifolin-7-O-β-D-glucoside (tricuspid) (3), quercetin-3-O-α-glucopyranosyl-(1 → 2)-β-D-glucopyranoside (4) and (−)-epicatechin(2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H chromene-3,5,7-triol (5) were isolated from mango leaves. In a laboratory bioassay, 50 ppm solution of compounds 3 and 4 caused yellowing of the parthenium seedlings. A 250 ppm solution of compound 4 also significantly reduced germination and the root and shoot lengths of parthenium seedlings. This study concludes that compound 4 exhibits herbicidal activity against parthenium weed.

Warburgia ugandensis, which is one of the indigenous species of Ethiopia, is known for its wide range of biological activities. A series of drimane sesquiterpenoids have been isolated from the stem bark of the plant. However, there is no report on the herbicidal potential of the plant against invasive weeds like Parthenium hysterophorus. In this study, the herbicidal potential of W. ugandensis against the P. hysterophorus weed was investigated. Following the bioassay protocol, muzigadial as powerful phytotoxic compound together with other eight compounds were isolated from the EtOAc soluble portion of the ethanol extract of the bark of the plant. These compounds were identified using different physical and spectroscopic methods. The isolated compounds are albicanyl acetate (35), caseamemin (36), β-sitosterol (37), muzigadial (38), cinnamolide-3β-acetate (39), ugandensidial (40), 11α-hydroxy muzigadiolide (41), polygodial (42) and 9-deoxymuzigadial (43). The first three compounds are new to the species W. ugandensis. Furthermore, two other compounds namely heptacosanol (44) and hentriacontane (45) were also isolated from this species. In summary, the purpose of this study, to the best of my knowledge, is to provide the three initially identified compounds from the plant material and provide information on the plant's potential utility in agricultural applications.

The “Allelopathic effects of plant parts of two invasive weeds on seed germination and seedling growth of maize varieties” was investigated at the Agriculture Graduate laboratory, The Bacha khan University Charsadda Pakistan during summer, 2018. The experiment was carried out in CRD design and factorial arrangements repeated thrice.Five maize varieties namely Azam, Babar, Pahari, Iqbal, and Jalal comprised factor A while Factor B consisted of water extracts from root, stem and leaf of invasive weeds; Parthenium hysterophorus and Xanthium strumarium. Distilled water was used as control for comparison. Data were recorded for percent germination (%), seedlings length (cm), shoot weight (g) and root weight (g). It was evident from the results that maximum germination (100 %), Seedling length (7.6 cm), shoot weight (164.88 g) and root weight (163.8 g) was recorded for control (water) treatments. However, among the tested extracts the minimum germination (80.9 %) of maize varieties were achieved under P. hysterophorus stem extract. Maize variety “Pharri” revealed highest sensitivity towards allelopathic potential of different extract, giving minimum (80.95 %) germination. On the other hand, the maize variety “Babar” showed strong resistance against all applied extracts (treatments) and showed 100% seed germination. In the light of the current results it is recommended that the farmer should discourage the growth of P. hysterophorus weed in their filed as it has strong allelopathic effects on maize crop. Moreover, the farmers should grow maize variety Babar instead of others as this variety showed strong resistant to the allelopathic effects of both the invasive weeds studied.

Valorization of Parthenium hysterophorus weed for cellulose extraction and its application for bioplastic preparation

Identifying optimal waveband positions for discriminating Parthenium hysterophorus using hyperspectral data