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Herbicide activity of volatile oils from Eucalypus citriodora against Parthenium hysterophorus
Abstract
The herbicidal effect of volatile oils from leaves of Eucalyptus citriodora against the noxious weed Parthenium hysterophorus was tested. In a laboratory bioassay, seed germination and seedling length, chlorophyll content and respiratory activity of Parthenium decreased with increased concentration of eucalypt oils from 0.2 to 5.0 nL mL-1. Germination was completely inhibited at 5.0 nL mL-1 eucalyptus oils. Further, for 4-week-old plants of Parthenium sprayed with different concentrations of volatile oils, visible damage increased and chlorophyll content and respiratory activity decreased with increased concentration from 0 to 100 μL mL-1, the week after spraying. At concentrations up to 50 μL mL-1, plants showed some recovery over time but plants sprayed with 75 and 100 μL mL-1 died 2 weeks after treatment. Plants sprayed with 50 μL mL-1 and higher concentrations of eucalypt oils were desiccated and wilted in appearance. At concentrations of 5–75 μL mL-1, eucalypt oils caused a rapid electrolyte leakage from the Parthenium plants thereby indicating an effect on membrane integrity. It is concluded that volatile oils from E. citriodora possess weed-suppressing ability and could be used as a potential bioherbicide for future weed management programmes.
... Finally, we will summarize the works about the herbicidal activity of EOs from different Eucalyptus species. The strong herbicidal potential of Eucalyptus EOs has been demonstrated [73][74][75]. One of the most studied EOs from Eucalyptus species is the EO from E. citriodora Hook (the accepted name of these species is Corymbia citriodora (Hook.) ...
... One of the most studied EOs from Eucalyptus species is the EO from E. citriodora Hook (the accepted name of these species is Corymbia citriodora (Hook.) K.D.Hill et L.A.S.Johnson), which has been tested against different weed species in many works [75][76][77] (Table 1), concluding that it can be an excellent candidate to be used as bioherbicide. However, Ibáñez and Blázquez [78] tested E. citriodora EO against P. oleracea, E. crus-galli and Lolium multiflorum Lam in vitro conditions finding no significant inhibitory effects on seed germination and hypocotyl length on the tested weeds at the concentrations assayed (0.125-1 μL/mL) ( Table 1). ...
... Phytotoxic effects of EOs that can be visible in treated plants, like growth reduction, chlorosis and burning of leaves, have been attributed to their interference with some processes in the plant cells, like inhibition of mitosis, decrease of cellular respiration and chlorophyll content, membrane depolarization and ion leakage, removal of the cuticular waxes, oxidative damages and microtubule polymerization [24]. EOs that alter the membrane integrity (e.g., E. citriodora EO), consequently increasing its permeability and enhancing the solute leakage [75], affect other physiological and biochemical processes linked to membrane functioning [64]. ...
Weeds are one of the major constraints in crop production affecting both yield and quality. The excessive and exclusive use of synthetic herbicides for their management is increasing the development of herbicide-resistant weeds and is provoking risks for the environment and human health. Therefore, the development of new herbicides with multitarget-site activity, new modes of action and low impact on the environment and health are badly needed. The study of plant-plant interactions through the release of secondary metabolites could be a starting point for the identification of new molecules with herbicidal activity. Essential oils (EOs) and their components, mainly terpenoids, as pure natural compounds or in mixtures, because of their structural diversity and strong phytotoxic activity, could be good candidates for the development of new bioherbicides or could serve as a basis for the development of new natural-like low impact synthetic herbicides. EOs and terpenoids have been largely studied for their phytotoxicity and several evidences on their modes of action have been highlighted in the last decades through the use of integrated approaches. The review is focused on the knowledge concerning the phytotoxicity of these molecules, their putative target, as well as their potential mode of action.
... Eucalyptus reported a combination of both positive and negative interactions on various crops and weed species (Schumann et al., 1995;Romagni et al., 2000;Sasikumar et al., 2001). Allelopathic potential of Eucalyptus has been reported by few studies on chlorophyll content, respiratory activity, seedling length, and germination (Kohli et al., 1998;Singh et al., 2005;Hegab et al., 2016;Wu et al., 2019) (Batish et al., 2004;Batish et al., 2007;Khan and Marwat et al., 2005;Babu and Kandasamy. 2008;Verdeguer et al., 2009;Wu et al., 2019). ...
... The exact mechanism, by which seedlings length is affected by Eucalyptus oil, could be due to the inhibition of mitosis in the growing cells, as essential oils are reported to inhibit sprout growth in potato by killing meristematic cells. The seedling length of parthenium was reduced by 56% due to Eucalyptus oil (Singh et al., 2005). Kohli et al., (1998) have mentioned that the oil present in the leaves coins with the leaf diffusibility, rate, and stomatal aperture and eventually leads to wilting of the plant species, thereby suppressed the growth. ...
Trees, especially fast-growing multipurpose species, are becoming an integral part of intensive commercial agroforestry models introduced in recent times. Yet, the major hindrance for their productivity and survival is weed infestation with its toxic effects. They eventually decline the biodiversity by smothering native plants and disturbing their ecological niche. Parthenium hysterophorus invasion is a worldwide threat and acts as a potential menace in the biological phenomenons of germination and growth, effecting plant biodiversity. Our study aimed to examine the outcome of aqueous leaf extract (ALE) and leaf oil (LO) of three exotic Eucalyptus species (E. citriodora, E. tereticornis, and E. camaldulensis) on germination and growth performance of Parthenium hysterophorus using two experiments. In the first experiment, we compared the inhibitory effect of aqueous leaf extract and leaf oil on seed germination of weed, while in the second experiment, we studied the different concentrations of aqueous leaf extract and leaf oil of promising Eucalyptus species from the first experiment on Parthenium hysterophorus. We measured the growth characteristics such as Germination percent, Speed of germination, Root length, Shoot length, Total seedling length, Seed vigor, and Phytotoxicity percent. The study highlights species E. citriodora found to be more promising for weed control and subsequently selected using different concentrations for the second experiment. Bioassay of E. citriodora oil at 5 ppm concentration was found to be more effective for weed suppression than aqueous extract concentrations. The study suggests an eco-friendly method to suppress the weed population and effective management in weed control.
... Eucalyptus reported a combination of both positive and negative interactions on various crops and weed species (Schumann et al., 1995;Romagni et al., 2000;Sasikumar et al., 2001). Allelopathic potential of Eucalyptus has been reported by few studies on chlorophyll content, respiratory activity, seedling length, and germination (Kohli et al., 1998;Singh et al., 2005;Hegab et al., 2016;Wu et al., 2019) (Batish et al., 2004;Batish et al., 2007;Khan and Marwat et al., 2005;Babu and Kandasamy. 2008;Verdeguer et al., 2009;Wu et al., 2019). ...
... The exact mechanism, by which seedlings length is affected by Eucalyptus oil, could be due to the inhibition of mitosis in the growing cells, as essential oils are reported to inhibit sprout growth in potato by killing meristematic cells. The seedling length of parthenium was reduced by 56% due to Eucalyptus oil (Singh et al., 2005). Kohli et al., (1998) have mentioned that the oil present in the leaves coins with the leaf diffusibility, rate, and stomatal aperture and eventually leads to wilting of the plant species, thereby suppressed the growth. ...
... Many studies have proved the herbicidal activity of Eucalyptus spp. EOs, for example, Eucalyptus camaldulensis EO, inhibited the germination and growth of Amaranthus hybridus and Portulaca oleracea [14], and the EO from E. citriodora was effective to control the invasive noxious weed Parthenium hysterophorus [15]. EOs from Lamiaceae and Asteraceae have also shown high potential for their use as natural herbicides [12,16,17]. ...
... Phytotoxicity level (mean ± standard deviation of main effects) and results of ANOVA on Erigeron bonariensis plantlets exposed to four EOs, applied by watering or spraying, at different doses and evaluated at1,5,10,15,20,25, and 30 days after treatment. ...
In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 µL/mL, with Fitoil used as emulsifier. In post-emergence, two ways of application were tested, irrigation and spraying. Several germination parameters (germination %, mean germination time, and synchrony of the germination process) were evaluated in pre-emergence tests, and the phytotoxicity level was assessed in post-emergence. In pre-emergence, all EOs significantly reduced seed germination as compared to the controls, ranking: T. capitata > E. camaldulensis > S. chamaecyparissus > M. piperita. The effectiveness of all EOs varied with the tested dose, always following the rank 2 μL < 4 μL < 8 μL, with T. capitata EO showing full effectiveness even at the lowest dose. In post-emergence, T. capitata was the most effective EO, inducing a rather complete inhibition of plantlet growth at the highest two doses. These EOs demonstrated to have good potential for the formulation of natural herbicides.
... Scientia Horticulturae 257 (2019) 108735 germination. The active, and yet destructive role of reactive oxygen species can result in lipid peroxidation and membrane disintegration (Kaur et al., 2010;Mutlu et al., 2011;Singh et al., 2005). Many studies have revealed that phenolic compounds and volatile monoterpenes can seriously interfere with metabolic processes during germination, seedling growth, and later stages of plant development Kaur et al., 2010;Nourimand et al., 2011;Poonpaiboonpipat et al., 2013;Scrivanti, 2010). ...
... There are some reports regarding the mode of action of allelochemicals in plants as they control or suppress the growth and development of the recipient plants. For example, their phytotoxicity could result from the impairment of photosynthesis and respiratory abilities by the constituents of monoterpenes and polyphenols (Singh et al., 2005). These results may either reflect the synergistic or additive effects of compounds in the allelochemical ingredients (Saharkhiz et al., 2010). ...
In the present study, variations were examined in the content and compositions of Vitex-pseudo-negundo leaf essential oil (EO). These evaluations were carried out at 2 different ontogenetic stages, i.e. before and during flowering. Fresh leaves of vitex were harvested and analyzed at these two stages. The EOs of air-dried samples were extracted by hydrodistillation. The yield of EOs (w/W%) significantly increased (P ≤ 0.05) in the leaves at the flowering stage (0.43%), compared to the stage before it (0.25%). The EOs were analyzed by gas chromatography (GC) and by GC–mass spectrometry (GC–MS). The main EO components in the leaves at these 2 stages were α-pinene (25.4–30.2%), limonene (11.9–12.5%), α-terpinyl acetate (22.6–29.5%) and (E)-caryophyllene (7.6–11.6%). Moreover, α-terpinyl acetate had its strongest presence at the flowering stage (29.5%), while α-pinene, limonene and (E)-caryophyllene showed their highest contents before the flowering stage (30.2, 12.5 and 11.6%, respectively). The phytotoxic activities of EOs were examined at the full flowering stage. These EOs were employed in concentrations of 0, 400, 800, 1200, 1600, 2000 and 2400 μL/L and were used on a crop, Lepidium sativum, and on two weeds, Amaranthus retroflexus and Taraxacum officinale. The EOs of vitex showed inhibitory effects on these species. The efficiency of inhibition depended on the type of species being treated with EO and on the concentration of EO being used.
... Parthenium hysterophorus L. is an aggressive weed having allelopathic effect and drastically retards the growth of many crop species. In India parthenium was found to invade the agriculture lands of sugarcane, rice (Singh et al., 2005) and inhibit the growth of pasture grasses, legumes, cereals, vegetables, forage crops, pulses, oil seeds other weeds and trees. Parthenium is considered as a noxious weed due to its allelopathic chemicals. ...
... The extract of Parthenium hysterophorus induced a variety of chromosomal aberrations in dividing cells, which increased significantly with increasing concentrations and durations of exposure. These similar experimental findings were observed in vigna radiata by Parthenium leaf extract(Rajendiran, 2005).Similar results on germination of seed were recorded in the Brassica species(Singh et al. 2005) by increase of parthenium concentration. ...
... The Eucalyptus species possess high allelopathic activity (Sasikumar et al. 2001 andSingh et al. 2005). Chromatographic analysis showed the presence of coumaric, gallic, gentisic, hydroxybenzoic, syringic and vanillic acids in Eucalyptus globulus leaf extract (Sasikumar et al. 2001 andEl-Rokiek et al. 2011). ...
... Likewise, Hanafy et al. (2012) reported that the highest values Sikandar et al. (2018) garlic extract treatment increased the growth parameters of pepper plant. The Eucalyptus species possess high allelopathic activity that might be inhibitors or stimulatory according to concentrations (Singh et al. 2005). These allelopathic extracts contained different phenolic acids which might be phytotoxic or promoters (Sasikumar et al. 2001). ...
Quinoa seeds contain highly nutritive compounds, so it acquired increasing interest during the last years A field experiment was conducted at the experimental station of Agricultural Production and Research Station, National Research Centre, El Nubaria Province, El Behaira Governorate, Egypt, during two successive winter seasons (2016/2017 and 2017/2018). In this experiment, quinoa plants were sprayed with clove extract of garlic or leaf extract of Eucalyptus globulus with concentrations 5, 10 and 15% in addition to the untreated control treatment. Quinoa plants were sprayed twice 86 and 93 DAS (days after sowing). The results of vegetative growth stages indicated increases in quinoa growth due to the treatments with different concentrations of the two mentioned extracts. The results also revealed increases in photosynthetic pigments constituents (chlorophyll a, chlorophyll b and carotenoids) of quinoa leaves. The results also indicated increases in yield and oil content as well as different studied metabolic activity. We can conclude from these results that spraying quinoa plants with natural clove extract of garlic or leaf extract of Eucalyptus for increasing growth and consequently yield.
... Essential oils are products of plant metabolism, of which terpenoids, especially monoterpenes and sesquiterpenes, are the major constituents of essential oils and can inhibit plant growth activity [64]. Singh et al. [65] found that volatile oils in eucalyptus had a complete inhibitory effect on the seed germination of Parthenium hysterophorus. The inhibition of plant seed germination by essential oils is universal; Ramezani et al. [66] extracted essential oils from Eucalyptus nicholii, Eucalyptus nicholii, Chamaecyparis lowsoniana and Chamaecyparis lowsoniana, which showed significant inhibition on the germination of weed seeds. ...
Germination inhibitors, which inhibit the germination of seeds, spores and other plant reproductive material, are abundant in the plant kingdom and include phenols, cyanides, alkaloids, essential oils, amino acids, etc. These inhibitors can be classified as germination destructors and germination retarders depending on whether they harm the morphology, structure and physiology of the seed. Germination retarders are closely related to seed dormancy, and exogenous retarders can be used to extend the “dormancy” period of non-dormant seeds or perishable seeds by applying the proper dosage. They have significant potential applications as preservatives for seed preservation following harvest or for the storage of long-term germplasm resources. Germination destructors, as a type of relatively high-efficiency, low-specificity “toxic chemicals”, are of significant benefit in the application of effective and environmentally benign herbicides. At present, the main problems related to the research methods of germination inhibitors include difficulty in determining the specific endogenous substances and the minimum inhibitory concentration to induce dormancy, as well as whether the application of exogenous inhibitors will cause physiological damage to seeds. In the future, we should strengthen the tracking of germination inhibitors, explore the mechanisms of action of specific substances and deeper molecular mechanisms and finally explore new developments and new applications of different inhibitors.
... Additionally, they provide donor plants with allelopathic properties and suppress seed germination and growth of other plants (Batish et al., 2008;Singh et al., 2006a). Essential oils from eucalypt (Eucalyptus spp.), clove (Eugenia caryophyllus), citronella and lemon grass (Cymbopogon spp.), peppermint (Mentha piperata), and red stem wormwood (Artemisia scoparia) have been found to possess herbicidal activity (Singh et al., 2005;Batish et al., 2007Batish et al., , 2008Dayan et al., 2009;Kaur et al., 2010). This property of essential oils bears a great sig-nifi cance in view of the environmental and health implications and herbicidal resistance of synthetic compounds. ...
Citronellol, an oxygenated monoterpene, is found naturally in the essential oils of several aromatic plants and has been reported to exhibit growth inhibitory and pesticidal activities. However, its mechanism of action is largely unexplored. We investigated the effect of citronellol, which is lipophilic in nature on membrane integrity in terms of lipid peroxidation, conjugated dienes content, membrane permeability, cell death, and activity of the enzyme lipoxygenase in roots of hydroponically grown wheat. Citronellol (50 - 250 μM) caused a significant inhibition of root and shoot growth. Furthermore, exposure to citronellol enhanced the solute leakage, increased the malondialdehyde content and lipoxygenase activity, and decreased the conjugated diene content. This indicates that citronellol induces generation of reactive oxygen species (ROS) resulting in lipid peroxidation and membrane damage. This was confirmed by in situ histochemical studies indicating cell death and disruption of membrane integrity. We conclude from this study that citronellol inhibits the root growth by ROS-mediated membrane disruption.
... In fact, the continued use of synthetic herbicides may threaten sustainable agricultural production and has resulted in serious ecological and environmental problems, such as the increased incidence of resistance in weeds to important herbicides and increased environmental pollution and health hazards (Narwall 1999;Heap 1999). Therefore, there has, recently, been growing interest in research concerning the possible use of plant extracts as an alternative to synthetic herbicides (Dudai et al., 1993;1999;Singh et al., 2005;Bozhuyuk, 2020;Karaman et al., 2021). Tursun et al. / Selcuk J Agr Food Sci, (2022) 36 (2): 275-281 Terpenoids, particularly monoterpenes and sesquiterpenes, are the main components of essential oils and are often responsible for their inhibitory activity. ...
The essential oils from oregano (Origanum syriacum L.) and laurel (Laurus nobilis L.), and their main components, namely, carvacrol, 1,8-cineole and α-pinene, were tested to determine their inhibitory effects on the seed germinations of three different weeds [redroot amaranth (Amaranthus retroflexus L.), wild licorice (Glycyrrhiza glabra L.), curled dock (Rumex crispus L.) and cutleaf ground-cherry (Physalis angulata L.)] and three crops [(wheat (Triticum aestivum L.), corn (Zea mays L.) and cotton (Gossypium hirsitum L.)]. Gas chromatography/mass spectroscopy (GC-MS) analysis showed that 1,8-cineole and carvacrol were the major components of laurel and oregano essential oils, respectively. An in-vitro bioassay seed germination test showed that oregano essential oil and carvacrol completely inhibited the germination of weeds at all the concentrations ranging from 1 to 5 µl/Petri dish, while seed germination of test weeds significantly decreased with increasing of the concentrations of laurel essential oil and its main components, 1,8-cineol and α-pinene ranging from 5 to 20 µl/Petri dish. Oregano essential oil and carvacrol were totally ineffective on cotton and corn germination (except for the concentration of 5 µl/Petri dish of cavracrol), whereas they had a strong inhibitory activity against wheat seeds. On the other hand, the laurel essential oil and its main component, 1,8-cineole, showed less selective action on test crop species. It could be concluded that volatile oil from O. syriacum and its main component, cavracrol, possessed a strong inhibitory effect on germination of the weeds and was totally selective action on some crops, and could be utilized as bioherbicide for future weed management programmes.
... This virus has shown high success at controlling Solanum viarum Dunal (tropical soda apple) in Florida (USA), as it can cause necrotic local lesions and hypersensitive response in the species, leading to plant death within 20 to 50 days [19,99,100]. It is also important to note that viral infectious material contains nucleic acid (DNA or RNA) and needs to be introduced into the living cells through macroscopic or microscopic injuries [98]. In this regard, TMGMV needs to be formulated with a carborundum and organosilicon adjuvant to help it penetrate the plant, and it should also be applied via (i) an abrade-and-spray application, (ii) high-pressure sprayers (>80 psi) or (iii) a wiper application [100,101]. ...
The intrusion of weeds into fertile areas has resulted in significant global economic and environmental impacts on agricultural production systems and native ecosystems, hence without ongoing and repeated management actions, the maintenance or restoration of these systems will become increasingly challenging. The establishment of herbicide resistance in many species and unwanted pollution caused by synthetic herbicides has ushered in the need for alternative, eco-friendly sustainable management strategies, such as the use of bioherbicides. Of the array of bioherbicides currently available, the most successful products appear to be sourced from fungi (mycoherbicides), with at least 16 products being developed for commercial use globally. Over the last few decades, bioherbicides sourced from bacteria and plant extracts (such as allelochemicals and essential oils), together with viruses, have also shown marked success in controlling various weeds. Despite this encouraging trend, ongoing research is still required for these compounds to be economically viable and successful in the long term. It is apparent that more focused research is required for (i) the improvement of the commercialisation processes, including the cost-effectiveness and scale of production of these materials; (ii) the discovery of new production sources, such as bacteria, fungi, plants or viruses and (iii) the understanding of the environmental influence on the efficacy of these compounds, such as atmospheric CO2, humidity, soil water stress, temperature and UV radiation.
... More than 50% of the agricultural land throughout the country is cultivated with wheat crop during its cropping season (Hussain et al., 2013;Matloob et al., 2020). However, impure seed, irrigation water, wind are the main factors of increasing unwanted weeds cause massive yield losses in wheat and other field crops (Singh et al., 2005;Akbar et al., 2011). On the one side, weed are the main source of animal feed, soil cover, biochar preparation and compost technology, but on the other hand increasing insect population, crop disease and minimize over crop production. ...
The aim of present study was to investigate the allelopathic impact of sunflower water extract integrated with affinity herbicide on weed management and production of wheat variety TD-1 under field condition. The trial was carried out in a three replicated and the average plot size was kept at 3x5m (15 m2). The obtained data showed that the all the treatments considerably (P<0.05) minimized weed density, weed fresh weight, weed dry weight and weed control up to 90.33, 89.31, 89.61, 90.33% with application of sunflower water extract (1:10) @ 20 L ha-1 (One spray at 25 DAS) + Affinity 50 WP @ 0.75 kg ha-1 (One spray at 25 DAS) than control treatment. The application of sunflower water extract (1:10) @ 20 L ha-1 (One spray at 25 DAS) + Affinity 50 WP @ 0.75 kg ha-1 (One spray at 25 DAS) significantly increased number of tillers (32.34%), plant height (14.59%), spike length (27.89%), grains spike-1 (16.80%), grain weight plant-1 (47%), seed index (19.60%) and grain yield (51%) of wheat as compared with control. Overall results indicated that the sunflower water extract integrated with herbicide can be successfully used to control the narrow and broad leaves in wheat crop.
... The data presented in Table (8) illustrated that the E. citriodora plants were irrigated every 8 days produced the highest percentage of essential oil giving values 1.21 and 1.34%, respectively, in the first and second seasons. Our results were in agreement with Gerami et al. [62] on Origanum vulgaris L. and Mazrou et al. [63] on lemongrass plant. ...
Abstract
The pot experiment was conducted in Horticulture Research Institute (HRI), Agricultural Research Center, Giza, Egypt during two successive seasons of 2020 and 2021 to study the effect of basil leaves extract (BLE) on growth, chemical composition and different properties for essential oil of Eucalyptus citriodora seedlings under different irrigation intervals. Results clarified that the vegetative growth parameters and photosynthetic pigments were increased in plants that were irrigated every 6 days but proline and MDA were decreased at the same treatment. While, leaf area showed high increment in plants irrigated every 4 days, whereas, all root traits, total sugars content in all organs and antioxidant enzymes activity (PPO, SOD, POD and CAT) were raised by irrigation intervals every 8 days. E. citriodora plants sprayed with BLE at rate 20% produced the highest value for all vegetative growth parameters and all chemical compositions except proline and MDA which showed the lowest value at the same rate. Irrigation every 6 or 8 days with spraying 20 or 40 % of BLE was the best treatments for production of essential oil fresh leaves. Main constituent of essential oil of Eucalyptus citriodora fresh leaves is citronellal which reached to 71.54% by irrigation every 8 days with spraying 40% of BLE, the oil was monoterpenoid 92.59- 97.93%. Oil and its major monoterpenes exhibited restrained to strong antioxidant activity.
... On the other hand, biological and natural herbicides such as oils from medicinal plants in low concentrations are effective and helpful in the control of Parthenium. [23] These oils have no or little effect on the current crops as much as on Parthenium. [24] Biological control Biological control has been proven to be the best method to control the spread of Parthenium. ...
Parthenium plant, in general, is known to be harmful, dangerous, and invasive in nature. It causes much economic
loss to farmers by affecting the cultivation of crops and considered to be a threat to primary production of crops and
biodiversity as well. Parthenium hysterophorus a weed belonging to the family Asteraceae, it is an erect short-lived
plant and is known for its fleshy growth along sides of abandoned places, roadsides, and uncultivated lands. This
weed is found in hot and humid climates around the globe. This invasive species is known with different names in
different countries such as carrot weed, star weed, congress grass, wild feverfew, ragweed, bitter weed, and white
top. The spread of P. hysterophorus has been found to cause enormous loss to biodiversity by replacing natural
ecosystems and sometimes known to cause total habit alternation. In this review article, we discuss P. hysterophorus
as a weed, its origin, reproductive bionomics, chemical composition, and its pharmaceutical potential as antibacterial,
anti-inflammatory, hypoglycemic, anti-HIV, and antitumor activity in detail.
... Allelopathy is one of these ways (Weston, 1996). Allelopathic compounds can reduce the use of synthetic herbicides and thus reduce environmental pollution and lead to more safe crops (Singh et al., 2002(Singh et al., , 2003(Singh et al., , 2005a. Among the natural plant products, essential oils constitute an important group of that provide a characteristic odor to the aromatic plants (Singh et al., 2002). ...
p class="042abstractstekst">In the present study the bioherbicidal activity of essential oils hydrodistilled from Nepeta glocephalata Rech.f and N . ispahanica Boiss were investigated on four weed species (barnyard grass ( Echinochloa crus-galli (L.) Beauv), redroot pigweed ( Amaranthus retroflexus L.), lambsquarters ( Chenopodium album L.) and canary grass ( Phalaris canariensis L.)). A total of 37 components were identified from the essential oils of N. glocephalata and N. ispahanica constituting approximately 98.61 % and 96.1 % of the oils, respectively. In laboratory bioassay different concentrations (0, 1, 2, 4 and 8 μl ml<sup>-1</sup>) of two Nepeta essential oils on germination, root and shoot length were studied. Results showed by increasing the concentration of oils, all studied traits of the weeds were decreased compared with control. In a glass house bioassay post-emergence application of Nepeta essential oils (1.25 %, 2.5 %, 5 % and 10 %, v/v) on 3-week-old weed plants caused visible injury (7-days after spray) ranging from chlorosis to necrosis of plant weeds. In foliar application under glasshouse conditions, both Nepeta essential oils reduced the seedling dry mass and concentrations of chlorophyll a chlorophyll b. The study concludes that Nepeta essential oils have phytotoxic effects and could be used as bioherbicides but the selectivity of these compounds should be considered also.</p
... Furthermore, the proper concentrations of minerals, vitamins, and -carotene found in moringa leaves may have influenced metabolic processes in a way that increased the internal phenolic content in black cumin leaves, either directly or indirectly 39 . Therefore, these aspects assist MLE to serve as growth enhancer and natural antioxidant 40 . Our results supported by the previous report of Nasir et al. 37 who revealed that the total phenolic content was enhanced as a result of MLE application at critical stages of plant growth. ...
The history of plants to be utilized as medicines is thousands of years old. Black cumin is one of the most widely examined plant possessing naturally occurring compounds with antimicrobial potential. Foliar application of growth stimulators is a successful strategy to enhance yield and quality in many crops. A field study was planned to apply growth stimulator like moringa leaf extract on black cumin crop grown under field conditions using RCB design with three replications. All other agronomic inputs and practices were uniform. The treatments were moringa leaf extract concentrations (10%, 20%), growth stages (40 days after sowing, 80 DAS, 120 DAS, 40 + 80 DAS, 40 + 120 DAS, 80 + 120 DAS, 40 + 80 + 120 days after sowing) and two controls unsprayed check (i.e. no moringa leaf extract, no water) and sprayed check (no moringa leaf extract + water). Application of 20% moringa leaf extract at stage-7 (40 + 80 + 120 days after sowing) had significantly increased plant height, branches plant ⁻¹ , essential oil content, fixed oil content, peroxidase value and iodine value of black cumin oil over unsprayed control. Application of moringa leaf extract showed maximum results and improves growth and yield of black cumin when applied at 40 + 80 + 120 days after sowing. As this study was only conducted using moringa leaf extract, it is advisable to conduct an experiment with various bio stimulants along with fertilizer combinations and growth regulators to check their synergistic effects for more reliable and acceptable recommendations in future.
... Several authors synthesized the herbicidal and phytotoxic properties of EOs (Blázquez, 2014;Raveau et al., 2020). Phytotoxic effects have been demonstrated for numerous EOs (Kordali et al., 2008;De Almeida et al., 2010;Kordali et al., 2009;Singh et al., 2005;Batish et al., 2007;Kaur et al., 2011;Palacios et al., 2010). However, some EOs were ineffective for weed control (De Almeida et al., 2010;Kordali et al., 2009). ...
Pest management in agriculture is badly needed because approximately one third of the world’s potential food supplies are lost to pests and diseases, and these losses would rise if crop protection were not implemented. In the last 40 years, the massive increase in the use of synthetic pesticides made it possible to increase food production. However, its excessive use is currently causing negative effects on health and the environment, as well as a rapid emergence of resistance in the pests. Growing social awareness about the impact of agricultural practices has also contributed to promoting the development of safer formulations for the advancement of sustainable agriculture. In recent years, there has been a greater interest in the use of alternative control strategies for the management of pests in crops, including the use of natural substances of plant origin such as essential oils, with the intention of introducing inputs eco-friendly farming. However, its application in agriculture usually faces some limitations. Essential oils present as limitations in their field application the stability and persistence of their effects over time. This chapter presents an overview of the use of essential oils to control phytopathogens and weeds in agricultural systems and different microencapsulation strategies that scientists implemented in order to avoid the disadvantages of applying pure oils. Therefore, the purpose of this review is to compile updated information on the innovative methods used for the development of formulations of the bio-pesticide based on essential oils reported in the scientific literature. The use of the formulations against phytopathogenic fungi, bacteria, insects, phytoparasitic nematodes and weeds are being investigated as alternatives to synthetic pesticides for the development of a more sustainable agriculture. Research trends are moving towards the development of greener agricultural formulations. The formulation of control agents using microencapsulation techniques improves their stability and biological activity, and therefore would allow their application on a larger scale, thus representing an innovative method for these products to be positioned on the market.
... Many plants, including weeds, have been investigated for their phytotoxic potential against different weeds [3]. These plants inhibit the germination and growth of different crops by releasing certain water-soluble phytotoxins into their adjacent environment [4,5]. Alien species chemicals are allelopathic to the native plant species that invade plants to establish in a new ecosystem and environment [6]. ...
Many phytochemicals can affect the growth and development of plants and insects which can be used as biological control agents. In this study, different concentrations of crude, hexane, chloroform, butanol, and aqueous extracts of Euphorbia nivulia Buch.-Ham., an endemic plant of the Cholistan desert in South Punjab of Pakistan, were analysed for their chemical constituents. Their various concentrations were also tested for their phytotoxic and insecticidal potential against duckweed, Lemna minor L., and the dusky cotton bug, Oxycarenus hyalinipennis Costa. various polyphenols, i.e., quercetin, gallic acid, caffeic acid, syringic acid, coumaric acid, ferulic acid, and cinnamic acid were detected in different concentrations with different solvents during the phytochemical screening of E. nivulia. In the phytotoxicity test, except for 100 μg/mL of the butanol extract gave 4.5% growth regulation, no phytotoxic lethality could be found at 10 and 100 μg/mL of all the extracts. The highest concentration, 1000 μg/mL, of the chloroform, crude, and butanol extracts showed 100, 63.1, and 27.1% of growth inhibition in duckweed, respectively. In the insecticidal bioassay, the highest O. hyalinipennis mortalities (87 and 75%) were recorded at 15% concentration of the chloroform and butanol extracts of E. nivulia. In contrast, the lower concentrations of the E. nivulia extracts caused the lower mortalities. Altogether, these findings revealed that E. nivulia chloroform extracts showed significant phytotoxicity while all the extracts showed insecticidal potential. This potential can be, further, refined to be developed for bio-control agents.
... leakage. High temperature damage cell membrane or membrane integrity hence increases membrane permeability which disturbs all other physiological and biochemical processes owing to shift in electrolyte proportions and the pH of the cell (Kaur et al., 2010;Singh et al., 2005;Ali et al., 2018) These results indicate that normal membrane permeability characteristics are seriously affected of sugarcane plant when heat stress is imposed. ...
... Inhibits cell division, abnormal root growth Zea mays [46] Caffiec acid Inhibits seed germination, plant growth, disruption of plant-water relationship, reduce chlorophyll contents Euporbia esula [47] 2-Benzoxazolinone (BOA) Inhibits plasma membrane bound H + -ATPase in roots Avena fatua [48] // Inhibits germination, seedling growth, induces oxidative stress Lactuca sativa [49] // Disruption of plant-water relationship, adverse effect on transpiration and photosynthesis Lactuca sativa [45] [50] Caffeic, p-coumaric, ferulic, salicylic acids Induces water stress Glycine max, Sorghum bicolor [51] Benzoic acid and cinnamic acid Disruption of membrane or alter membrane permeability, efflux of ions, reduce chlorophyll content by damage of thylakoid membrane [52] Ferulic and p-hydroxybenzoic acids Inhibition of photosynthesis, growth and carbon isotope discrimination Lactuca sativa [53] Benzoxazolin-2(3H)-one (BOA) and Inhibition of leaf water content, photosystem-II Dactylis [35] cinnamic acid efficiency, photon energy, photochemical quenching glomerata, Lolium perenne, Rumex acetosa ...
Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and eco-physiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including benzoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement.
... Inhibits cell division, abnormal root growth Zea mays [46] Caffiec acid Inhibits seed germination, plant growth, disruption of plant-water relationship, reduce chlorophyll contents Euporbia esula [47] 2-Benzoxazolinone (BOA) Inhibits plasma membrane bound H + -ATPase in roots Avena fatua [48] // Inhibits germination, seedling growth, induces oxidative stress Lactuca sativa [49] // Disruption of plant-water relationship, adverse effect on transpiration and photosynthesis Lactuca sativa [45] [50] Caffeic, p-coumaric, ferulic, salicylic acids Induces water stress Glycine max, Sorghum bicolor [51] Benzoic acid and cinnamic acid Disruption of membrane or alter membrane permeability, efflux of ions, reduce chlorophyll content by damage of thylakoid membrane [52] Ferulic and p-hydroxybenzoic acids Inhibition of photosynthesis, growth and carbon isotope discrimination Lactuca sativa [53] Benzoxazolin-2(3H)-one (BOA) and cinnamic acid Inhibition of leaf water content, photosystem-II efficiency, photon energy, photochemical quenching Dactylis glomerata, Lolium perenne, Rumex acetosa [35] Cinnamic acid ...
adela@uvigo.es (A.M.S.-M.), mreigosa@uvigo.es (M.J.R.) Abstract: Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and eco-physiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including ben-zoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement. Citation: Hussain, M.I.; Danish, S.; Sánchez-Moreiras, A.M.; Vicente, O.; Jabran, K.; Chaudhry, U.K.; Branca, F.; Reigosa, M.J. Unraveling Sor-ghum Allelopathy in Agriculture: Concepts and Implications. Plants 2021, 10, 1795. https://doi.
... Inhibits cell division, abnormal root growth Zea mays [46] Caffiec acid Inhibits seed germination, plant growth, disruption of plant-water relationship, reduce chlorophyll contents Euporbia esula [47] 2-Benzoxazolinone (BOA) Inhibits plasma membrane bound H + -ATPase in roots Avena fatua [48] // Inhibits germination, seedling growth, induces oxidative stress Lactuca sativa [49] // Disruption of plant-water relationship, adverse effect on transpiration and photosynthesis Lactuca sativa [45] [50] Caffeic, p-coumaric, ferulic, salicylic acids Induces water stress Glycine max, Sorghum bicolor [51] Benzoic acid and cinnamic acid Disruption of membrane or alter membrane permeability, efflux of ions, reduce chlorophyll content by damage of thylakoid membrane [52] Ferulic and p-hydroxybenzoic acids Inhibition of photosynthesis, growth and carbon isotope discrimination Lactuca sativa [53] Benzoxazolin-2(3H)-one (BOA) and cinnamic acid Inhibition of leaf water content, photosystem-II efficiency, photon energy, photochemical quenching Dactylis glomerata, Lolium perenne, Rumex acetosa [35] Cinnamic acid ...
Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and eco-physiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including benzoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement.
... Weeds displace native species, degrade indigenous ecosystem, deplete natural diversity, contribute to land and water degradation, and reduce agricultural productivity (McAlpine et al., 2015). They can also create health hazard, as the pollen grains are mostly allergenic (Singh et al., 2005). The control of noxious weeds is thus imperative but the chemical-based method which is popular globally is in recent decades generating maladies and raising environmental safety concerns (Harding & Raizada, 2015). ...
The study was undertaken to prime a strain of Lasiodiplodia pseudotheobromae (C1136) as a mycoherbicidal agent against Amaranthus hybridus L. (pigweed) utilizing various agricultural wastes for its production. The rate of mortality and dry weight reduction of the target weed was determined in both the greenhouse and field conditions. The mycoherbicidal efficacy of the highly virulent isolate (strain C1136) was established based on the influence of the dew period, temperature, and inoculum concentration as well as plant growth stages. A dew period of 72 h was observed to be the highest time period necessary to obtain 90.6% mortality rate while there was no death observed at 0- and 12-h dew period treatments, respectively. Maximum disease development and mortality rate was observed at 25 °C on the target weed. It was observed that the inoculum concentration at 4 × 106 CFU/ml had the highest dry weight reduction of 98.60% and mortality rate of 89.4%. Groundnut husks gave comparatively the best spore yield (9.8 × 107 CFU/g), and yam peels gave the least (1.1 × 107 CFU/g). Greenhouse and field trials showed that the strain C1136 had a strong antagonistic effect on the test weed. This study therefore confirms the suitability of the strain C1136 as a potentially effective bioherbicidal agent that is eco-friendly. Furthermore, the cheap strain’s observed responses to the environmental parameters assessed in the study affirmed its sustainability and possibility as a permanent substitute for synthetic herbicides in agrosystems’ practices for effective weed management.
... Chlorophyll content and respiratory activity decreased for 4-week-old plants. [39] 3.2. Types of Active Compounds and Plant Extracts Tested as Bioherbicides 3. ...
In all farming systems, weeds are the most expensive pest to manage, accounting for 30% of potential losses. In organic farming, the problem may be further amplified by restrictions on herbicides, thus making weeds the main problem faced by organic farmers in the field. In this sense, much research is focusing on the allelopathic potential of plants as an ecological weed control tool. Many plant species can release allelopathic compounds with high phytotoxicity that can be used in weed control. Species belonging to the Lamiaceae family have been studied widely for this purpose, and their essential oils (EOs) appear to be promising bioherbicides. However, there are still many challenges for their development. Considering these aspects, a review of the bioherbicidal effect of EOs from Mediterranean Lamiaceae could help identify the most effective ones and the challenges for their actual development.
... During the metabolism processes, plants produce secondary compounds that are either toxic or stimulate to the microorganisms. These compounds are extracted from different plants known as allelopathic plants, such as all trees that belong to the Eucalyptus species, which possess a high effectiveness of the chemical antibiotic (Sasikumar et al., 2001 andSingh et al., 2005). Allelochemicals sources are either in leaves, stem, tree phloem, live or dead plants can be classified into terpenes, glucocides, coumanines, aldehyds and phenolic compounds, all of which Eucalyptus leaves are a major source (Khan et al., 2007). ...
This experiment was aimed to evaluate the effect of Eucalyptus camaldulensis D. aqueous extract out of Eucalyptus bark (0, 5%, 10%, 20%) and Eucalyptus leaves (0, 50, 100, 200 g/L) on the ability of production and Inhibition of For some polluted fungi in the agricultural medium and the increase of some active compounds with a medicinal effect in Oyster mushrooms. Results revealed that the aqueous extract of Eucalyptus bark (10%) gave the highest values in total wet yield (350.3 g/kg agriculture medium), Total dry yield (34.73 g/kg agriculture medium), dry matter percent (9.913%), Biological efficiency (70.07%), fruit body average (49.87g) and dried fruit content of protein. Also the application of eucalyptus bark at 20%, eucalyptus leaves at 200 gm/L and eucalyptus leaves at 100 gm/Land the application of eucalyptus cortex at 10% were significantly Inhibited the polluted microorganisms in the agricultural medium (0, 0, 1, 2.67%) respectively, while the application of eucalyptus bark at 20% has significantly increased the fruit content of total phenols and total flavonoids which were peaked at 0.602 and 0.5300 mg/g of dried fruit weight of Oyster mushrooms.
... During the metabolism processes, plants produce secondary compounds that are either toxic or stimulate to the microorganisms. These compounds are extracted from different plants known as allelopathic plants, such as all trees that belong to the Eucalyptus species, which possess a high effectiveness of the chemical antibiotic (Sasikumar et al., 2001 andSingh et al., 2005). Allelochemicals sources are either in leaves, stem, tree phloem, live or dead plants can be classified into terpenes, glucocides, coumanines, aldehyds and phenolic compounds, all of which Eucalyptus leaves are a major source (Khan et al., 2007). ...
This experiment was aimed to evaluate the effect of Eucalyptus camaldulensis D. aqueous extract out of Eucalyptus bark (0, 5%, 10%, 20%) and Eucalyptus leaves (0, 50, 100, 200 g/L) on the ability of production and Inhibition of For some polluted fungi in the agricultural medium and the increase of some active compounds with a medicinal effect in Oyster mushrooms. Results revealed that the aqueous extract of Eucalyptus bark (10%) gave the highest values in total wet yield (350.3 g/kg agriculture medium), Total dry yield (34.73 g/kg agriculture medium), dry matter percent (9.913%), Biological efficiency (70.07%), fruit body average (49.87g) and dried fruit content of protein. Also the application of eucalyptus bark at 20%, eucalyptus leaves at 200 gm/L and eucalyptus leaves at 100 gm/Land the application of eucalyptus cortex at 10% were significantly Inhibited the polluted microorganisms in the agricultural medium (0, 0, 1, 2.67%) respectively, while the application of eucalyptus bark at 20% has significantly increased the fruit content of total phenols and total flavonoids which were peaked at 0.602 and 0.5300 mg/g of dried fruit weight of Oyster mushrooms.
... Bidens pilosa, Digitaria pertenuis, Eragrostis cilianensis, Setaria geniculata (Cao and Luo 2005) [3] . Similarly, Eucalyptus citriodora oil completely inhibited the germination of noxious weed P. hysterophorus (Singh et al.2005) [22] . ...
Woody perennials release some phytochemicals into the soil which adversely affect the germination and yield of understorey crops. Allelopathic interactions in tree crop associations in agroforestry greatly influence the crop production. When the trees and crops grown together they interact with each other either inhibiting or stimulating their growth or yield through direct or indirect allelopathic interaction. The consequent effects include inhibited or retarded germination rate, reduced roots or radical and shoot or coleoptiles extension, lack of root hairs and swelling or necrosis of root. Thus. it plays an irnportant role in an agroforestry system and it is clear that a better understanding of allelopathy can help in developing more sustainable agroforestry system.
... tissues completely diminished seed germination percentage, seed vigor, radicle length and plummule length of Parthenium hysterophorus L. at any concentration applied in the study of Kohli et al. (1998). Complete control of the same weed species has been recorded 2 wk after treatment with E. citriodora essential oils at 75 and 100 μL mL -1 (Singh et al., 2005). Aquaeous extracts as derived from fresh leaves of E. citriodora reduced A. fatua root length by 60% when applied at 10% (v/v) concentration in comparison to the control treatment in the study of El-Rokiek and Eid (2009) and were more efficient than extracts derived from dry leaves. ...
Eucalyptus spp. and Acacia spp. have been reported as major invaders in several regions and Mediterranean climates. It has been documented that E. globulus and E. camaldulensis can serve as resources of allelochemicals, which can be used as tools of control strategy of noxious weed species infesting the agricultural areas of the Mediterranean region. Additionally, the remarkable allelopathy potential of A. dealbata Link against various weed species has been highlighted in many recent studies. There is also evidence that other species belonging to Acacia spp. can suppress the native vegetation, including weeds, due to their allelopathic potential. However, allelochemical extracts from different plant tissues seem variable in terms of their effects on various species germination and growth parameters. Furthermore, the effectiveness of the allelochemicals in weed management is also a matter of choosing the most appropriate application rate at any case. In the present review, aspects of the potential role of Eucalyptus spp. and Acacia spp. allelochemicals in weed management were discussed. Further research is needed in order to optimize the use of such allelochemicals produced by invasive plants in the Mediterranean region in both organic and sustainable agriculture systems.
... However its success was reported to be limited only from Karnataka. According to Singh et al., (2005), Eucalypt oils have a potential for suppressing the emergence, growth and biomass accumulation in Parthenium. On the other hand Batish et al., (2004) pointed that in order to control Parthenium on long-term based community participation is crucial in addition to the integrated use of other methods. ...
... The oil of C. aurantifolia was the most effective at concentration of 10 μL/Petri dish, whereas the oil of C. lemon was the less effective one. Although there were no reported studies on the effects of four tested Citrus oils on seed germination, some of other essential oils were reported to cause a reduction of seed germination (Fujihara and Shimizu, 2003;Singh et al., 2005;Paudel and Gupta, 2008;Kordali et al., 2009;Verdeguer et al., 2009). ...
... Similar results have been reported in [24] where the phytotoxicity of nineteen essential oil components was studied. Also, barnyardgrass, the common lambsquarters, sterile wild oat, short-spiked canarygrass and ragweed parthenium (Parthenium hysterophorus L.) germination and growth were further reduced with increasing essential oil concentration [4,27,28]. ...
Essential oils are a plentiful source of plant compounds for potential use in the development of natural herbicides. With this in mind, the phytotoxicity of ten major essential oil components of lavender (Lavandula angustifolia Mill.) on the weed species bristly foxtail (Setaria verticillata (L.) P. Beauv.) was determined using a perlite-based Petri-dish bioassay. Their phytotoxicity was also compared with that of well-known phytotoxic essential oil components (carvacrol, thymol, carvone and eugenol) of oregano (Origanum vulgare L.) and clove (Syzygium aromaticum (L.) Merr. & L.M. Perry) essential oils. Potential synergistic or antagonistic effects between carvacrol or eugenol with other components of lavender essential oil were investigated. Regarding the most phytotoxic components, terpinen-4-ol at 80 nL/cm3 completely inhibited the germination and root length of bristly foxtail, displaying similar phytotoxicity to carvone and thymol. Like carvacrol, lavandulol and linalyl acetate caused total (100%) germination and root length reduction of bristly foxtail at 160 nL/cm3, while the same effect was achieved by lavandulyl acetate at 320 nL/cm3. A synergistic effect was also observed when carvacrol or eugenol were combined with ocimene, 3-octanone, α-terpineol or terpinen-4-ol. Focusing on the development of alternative weed control strategies, lavender essential oils containing high concentrations of terpinen-4-ol, lavandulol or linalyl acetate could be useful for the production of natural herbicides. These essential oil components combined with selected oregano or clove essential oil components, increase phytotoxicity and weed control due to the synergistic effect observed when in mixture.
... These phytotoxic effects have been demonstrated for Amaranthus retroflexus, Chenopodium album and Rumex crispus being completely inhibited in contact with Origanum acutidens EO [135], for Raphanus sativus, Lactuca sativa and Lepidium sativum tested with EO of Thymus vulgaris, Verbena officinalis and Melissa officinalis [136] and for A. retroflexus, Cirsium arvense and Lactuca serriola treated with Achillea gypsicola and Achillea biebersteinii EO [137]. Furthermore, visible damage on a grown weed are reported on Parthenium hysterophorus [138] and on little seed canary grass [139] in contact with Eucalyptus citriodora EO. However, a few EO have been demonstrated ineffective for the purpose of weed control. ...
Naturally produced by aromatic plants, essential oils (EO) contain a wide range of volatile molecules, including mostly secondary metabolites, which possess several biological activities. Essential oils properties such as antioxidant, antimicrobial and anti-inflammatory activities are known for a long time and hence widely used in traditional medicines, cosmetics and food industries. However, despite their effects against many phytopathogenic fungi, oomycetes and bacteria as well as weeds, their use in agriculture remains surprisingly scarce. The purpose of the present review is to gather and discuss up-to-date biological activities of EO against weeds, plant pathogenic fungi, oomycetes and bacteria, reported in the scientific literature. Innovative methods, potentially valuable to improve the efficiency and reliability of EO, have been investigated. In particular, their use towards a more sustainable agriculture has been discussed, aiming at encouraging the use of alternative products to substitute synthetic pesticides to control weeds and plant diseases, without significantly affecting crop yields. An overview of the market and the recent advances on the regulation of these products as well as future challenges to promote their development and wider use in disease management programs is described. Because of several recent reviews on EO insecticidal properties, this topic is not covered in the present review.
... has been reported to be a good source oil (lemon-scented Eucalyptus), which is used for pharmaceutical, perfumery and other related industries and was reported as non-toxic under the GRAS (Generally Regarded as Safe) category by Food and Drug Administration of the USA [15]. C. citriodora leaf EOs have a broad spectrum of uses such as antibacterial [16,17], pesticide [18][19][20], nematicidal [21], antifungal [13,17], and herbicidal [22] uses, and moderate to strong antioxidant activities [23] being rich in monoterpenoids compounds [23][24][25]. ...
The present study described the possibility of using wood-treated oil-fungicide of lemon-scented gum (Corymbia citriodora) from newly emerged leaves and unripened fruits against the infestation of Fusarium culmorum, Rhizoctonia solani and Penicillium chrysogenum. Air-dried wood samples of Melia azedarach were treated with the extracted oils from leaves and unripened fruits from C. citriodora. The main chemical constituents identified in the essential oil (EO) from leaves were citronellal (55.31%), citronellol (21.03%) and isopulegol (10.79%), while in unripened fruits were α-pinene (17.86%), eudesmol (13.9%), limonene (9.19%), γ-terpinen (8.21%), and guaiol (7.88%). For recovered oils (ROs), the major components from leaves were D-limonene (70.23%), γ-terpinene (13.58%), β-pinene (2.40%) and isopregol (2.23%), while, 4-terpineol (21.35%), cis-β-terpineol, (19.33%), D-limonene (14.75%), and γ-terpinene (7.42%) represented the main components in fruits. EOs from leaves and fruits at the amounts of 100, 50 and 25 µL showed the highest inhibition percentage (IP) of 100% against F. culmorum and P. chrysogenum compared to control treatment, while at the amounts of 100, and 50 µL showed 100% IP of R. solani. Wood treated with ROs from leaves and fruits showed IPs of 96.66% and 93.33%, respectively, against the growth of R. solani. The mass spectra of the main components of C. citriodora leaves and fruits’ EOs have been recorded in electron ionization mode at 70 eV and fragmentation has been reported and discussed. On the other hand, different quantum parameters such as the heat of formation, ionization energy total energy, binding energy, electronic energy and dipole moment using the modified neglect of diatomic overlap (MNDO) semi-empirical method have been calculated.
... This new radical does not react with lipids but with other similar molecules; generating a non-radical product or quinones, which can be considered antioxidants, after undergoing further oxidation. 28 This study sought to evaluate the subchronic toxicity in Carassius auratus. The growth of all the goldfish was isometric. ...
... Even 10 Gy irradiation dose reduced the content of chlorophyll in irradiated plantlets by 18.5% [56]. Singh et al. [57] reported that application of 1 nl/ml eucalyptus essential oil resulted in reduction of total chlorophyll contents by 50% in Parthenium hysterophorus seedlings. Results obtained in this study revealed that light-activated Chl-CHS did not affected chlorophyll a and chlorophyll b content in treated sprouts (Fig. 6). ...
The present study clearly demonstrated the significant antifungal activity of chlorophyllin-chitosan complex (Chl-CHS) after activation with visible light. This phenomenon afterwards was successfully applied for better microbial control of highly popular food- germinated wheat sprouts.
Obtained results indicated that photoactivated Chl-CHS complex (0.001% Chl-0.1% CHS and 0.005% Chl-0.5% CHS, 405 nm, 76 J/cm²) considerably inhibited (83%) the growth of dominating sprout pathogenic microfungus Fusarium graminearum in vitro. Moreover, obvious delay of fungus growth by 4 days after treatment was observed. The efficiency of antifungal treatment strongly depended on used Chl-CHS complex concentration.
The coating of wheat grains with Chl-CHS (0.005% Chl–0.5% CHS) and illumination with visible light (405 nm; 76 J/cm²) inactivated the molds on the surface of grains by 79%. It is important to note, that no grain surface microstructure damage observed by SEM imaging have been found. No inhibiting effects on seed germination process, viability, average weight of grains, length of seedlings and content of chlorophyll a and chlorophyll b in the seedlings or eventually visual quality after Chl-CHS coating of grains and illumination with visible light have been observed.
In conclusion, chlorophyllin-chitosan coating in the concert with visible light has great potential as cost-effective, environmentally friendly and sustainable strategy for better microbial control of highly contaminated sprouts.
... First is to use allelopathic cover crops in rotations, or apply residues of allelopathic plants as mulches (Caamal-Maldonado et al., 2001;Dhima et al., 2006). Another promising way to use allelopathy in weed control is using water extracts of allelopathic plants as herbicides (Dhima et al., 2009;Singh et al., 2005;White et al., 1989). Several researchers have described the application of allelopathic plant water extracts for weed suppression (Dhima et al., 2009;Jamil et al., 2009). ...
Crude oil exploration activities have impacted the land, air, and water negatively in places where such activities are taking place. These impacts generally imply low soil fertility, which in turn implies low agricultural productivity and a reduced source of livelihood in affected areas. Its effect also includes the loss of major soil nutrients that are necessary for food and fiber production. Several research papers were reviewed on the effects of crude oil exploration on global food production and efforts being made to alleviate this negative impact. The reviewed literatures includes places where crude oil exploration activities have been carried out. Several works of literatures reviewed indicated that there is a downward decline in food production due to the severe nature of damage to the environment as a result of crude oil spill on the environment. Consequently, there have been significant advances in regulation for protecting the environment in developed and developing countries, including the development of remediation frameworks and guidelines. On the other hand, studies have rarely reported on the risks and health effects of contaminants in developing regions and there is scarce information regarding contaminated land assessment and environmental remediation. Coordinated efforts are needed to increase the production of food but to remediate the impact on the environment to a level that will not hinder food production and threat to well-being of the inhabitants of these places where exploration is taking place.
In right now we are confronting the pervasion of Parthenium hysterophorus all over the place. It is accessible in stocks around the rail route tracks, in exposed lands, in farming fields, in plantations and in backwoods, it attacks significant part of Indian mainland. We are knowing all about Parthenium hysterophorus poisonous properties and need to control its invasion. Nonetheless, just controlling its isn't an answer eliminate it however it very well may be overseen by means of its use for various purposes. As of late a ton of exploration has been proceeding to investigate the use properties of Parthenium. This survey article presents a few properties and utility capability of Parthenium finished up by different scientists.
Solanum elaeagnifolium Cav (silverleaf nightshade) is a deep‐rooted, multi‐stemmed, perennial, herbaceous woody plant that has been observed to threaten agricultural and native biodiversity worldwide. It is widely agreed that without efficient integrated management, S. elaeagnifolium will continue to cause significant economic and environmental damage across multiple scales. It is estimated that the annual economic impact of S. elaeagnifolium in Australia exceeds AUD $62 million, with this figure likely to be much higher in other countries invaded by this plant. It can also tolerate a high level of abiotic stress and survive in a range of temperatures (below freezing point to 34°C) and areas with an average yearly rainfall between 250 and 600 mm. Its extensive deep taproot system is capable of regenerating asexually and with its many seed dispersal mechanisms; it can quickly spread and establish itself within a region. This makes containment and management of the species especially challenging. Previous management has largely been focused on biological control, competition, essential oils, grazing pressure, herbicide application and manual removal. Despite the large range of available management techniques, there has been little success in the long‐term control of S. elaeagnifolium, and only a handful of methods such as essential oils and herbicide application have shown reasonable success for controlling this weed. Therefore, this review aims to synthesise the identified and potentially useful approaches to control S. elaeagnifolium that have been recorded in the literature which deal with its biology, distribution and management. It also explores previous and current management techniques to ascertain the research gaps and knowledge required to assist in the effective and economically sustainable management of this invasive weed.
Several species of the genus Eucalyptus are used in many traditional medicine systems for the treatment of respiratory tract infections, colds, flu, sore throats, and bronchitis. The genus Eucalyptus (Myrtaceae) is a well‐known natural source of bioactive phloroglucinols. These polyphenolic compounds bear an aromatic phenyl ring with three hydroxy groups (1,3,5‐trihydroxybenzene) which have been exhibiting a variety of biological activities such as antimicrobial, anticancer, anti‐allergic, anti‐inflammatory, and antioxidant activities. This review summarizes the literature published from 1997 until the end of 2021 and addresses the structure diversity of phloroglucinols isolated from Eucalyptus species and their biological activities. Phloroglucinol‐terpene adducts are the main class of compounds that have been reported in this genus.
Herbicides are used extensively to control invasive plants in natural areas but, herbicide application often has undesired effects on non-target plants. Using a lab bioassay, we investigated the impacts of glyphosate and two bioherbicides (cinnamon plus clove oil, and pelargonic acid) on the establishment of bryophyte and fern propagules from an urban woodland park soil propagule bank. Mosses were slower to emerge and establish in soil treated with cinnamon plus clove oil than soil treated with pelargonic acid or glyphosate. Fern gametophyte establishment was negatively affected by glyphosate but not by the two bioherbicides. Results from this study confirmed those of a previous field study indicating that an herbicide containing pelargonic acid could be useful for controlling non-native plants in locations suspected of harboring high biodiversity in soil propagule banks.
Background: Medicinal plant contain phytochemicals which have inhibitory effects on plant pathogens. Weeds compete with the main crops and reduce the growth, yield, and quality of agricultural products to some extent. One of the most common methods of reducing weed damage is the use of chemical herbicides. Due to the side effects that chemical herbicides on human health and the environment, there is a need to replace biocompatible and low-risk herbicides. Objective: In this study, the allelopathic properties of the Ferula assa-foetida L. essential oil and castor oil (Ricinus communis L.) have been investigated as a botanical herbicide to prevent germination of redroot pigweed seeds (Amaranthus retroflexus L.). Methods: In this regard, an herbal formulation based on Ferula assa-foetida essential oil and castor oil was prepared and its effect on the germination of redroot pigweed seeds was studies in laboratory conditions. The chemical composition of the herbal formulation was analyzed by GC/MS. Results: The results showed that this herbal formulation in concentration 0.75 % and 1 % inhibits the germination of weed seeds about 70 %. The main constituents of Ferula assa-foetida and Ricinus communis were (E)-1-propenyl sec-butyl disulfide (43.9 %) and ricinoleic acid methyl ester (58.1 %), respectively. Conclusion: It was found that the studied botanical formulation has herbicidal properties. Therefore, more research is needed to achieve promising results in order to replace chemical herbicides with botanical herbicides.
L'objectif du travail effectué, était de montrer l'action des huiles essentielles, de deux plantes aromatiques avérées pesticides (Ocimum gratissimum et Cymbopogon citratus), sur les paramètres agromorphologiques du cotonnier. Les huiles essentielles ont Effets des Huiles Essentielles de Ocimum gratissimum L. et de Cymbopogon citratus Stapf sur les Paramètres de Croissance et de Production du Cotonnier en Côte d'Ivoire 22 été extraites et caractérisées. Au champ, les cotonniers ont été soumis aux effets des extraits huileux et d'un insecticide chimique par pulvérisation foliaire toutes les deux semaines du 45 ème au 115 ème jour après la levée. Les résultats ont révélé que l'extrait de O. gratissimum renfermait de fortes proportions en monoterpènes hydrocarbonés tandis que celui de C. citratus était riche en éléments oxygénés. A la concentration de 5 %, les huiles essentielles ont significativement freiné la croissance caulinaire des cotonniers (0,49 cm/j). A cette teneur, les cotonniers traités avec l'extrait de C. citratus ont obtenu le nombre le plus faible de capsules vertes (9,61 capsules/plantes) contrairement à celui de O. gratissimum (12,55 capsules/plante) et du produit chimique (13,15 capsules/plante). A la production, les cotonniers traités avec l'insecticide de synthèse ont présenté de plus fortes valeurs de poids moyen capsulaire (2,03 g), de rendement en graine (53,63 %), de poids de 100 graines ou seed index (7,55 g) et de meilleur rendement en coton-graine (963,28 kg/ha). Cependant, l'application des huiles essentielles a induit l'obtention d'un bon rendement en fibres (44,16 %). Relativement à la chute des organes, les produits évalués n'ont pas provoqué de façon significative l'abscission des capsules vertes. Globalement, les cotonniers protégés avec l'extrait de O. gratissimum ont été plus productifs que ceux traités avec celui de C. citratus. Abstract The objective of this work was carried out to show the action of essential oils, of two proven pesticidal aromatic plants (Ocimum gratissimum and Cymbopogon citratus), on the agromorphological parameters of cotton plants. The essential oils have been extracted and characterized. In the field, cotton plants were subjected to the effects of extracts and a chemical insecticide by foliar spraying every two weeks from 45 to 115 days after emergence. The results revealed that the extract of O. gratissimum contained high proportions of hydrocarboned monoterpenes while that of C. citratus was rich in oxygenated elements. At a concentration of 5 %, essential oils significantly slowed down the stem growth of cotton plants (0.49 cm/d). At this level, cotton plants treated with C. citratus extract obtained the lowest number of green bolls (9.61 bolls/plants) as opposed to O. gratissimum (12.55 bolls/plant) and chemical (13.15 bolls/plant). At production, cotton plants treated with synthetic insecticide had higher values for capsular average weight (2.03 g), seed yield (53.63 %), seed index (7.55 g) and higher seed cotton yield (963.28 kg/ha). However, the application of essential oils resulted in a good fibre yield (44.16 %). With regard to organ failure, the products evaluated did not significantly cause the shedding of the green bolls. Overall, cotton plants protected with O. gratissimum extract were more productive than those treated with C. citratus.
An experiment was conducted to investigate the allelopathic effect of three range species, C. spinosa, P. harmala and H. angustifolia on germination and seedling growth of alfalfa and wheat. The experiment was performed at the Faculty of Natural Resources, Yazd University, in 2002. A completely randomized design with three replications was carried out in a factorial combination of three plant extracts (C. spinosa, P. harmala and H. angustifolia) and distilled water as control, two extract concentrations (50% and 100%) and two target species (alfalfa and wheat). Results indicated that the C. spinosa extract caused the greatest inhibitory effect on test plants. Reductions in seed germination, shoot length and weight were 86, 98 and 99%, respectively compared to control. Results of this experiment also showed that C. spinosa extract had a highly significant inhibitory effect on root length and weight when compared to control. Between two concentrations, 100% concentration has more inhibitory effect on the average of germination and shoot weight as well as shoot length. But, there was no significant difference between root weight and root length. The results of this experiment also showed that the inhibitory effects of both concentrations were higher on alfalfa than wheat.
Biodegradable materials of Eucalyptus camaldulensis, Rosmarinus officinalis, and Pinus brutia were applied in this research to protect wool fabrics against Anthrenus verbasci. To do so, alcoholic extraction of the aforementioned compounds was first carried out and then, preventive protection and optimization of wool fabric mothproofing property, using pentagonal design and response surface method, was conducted; up to now, such a process was not reported and presented. Vicinity time and concentrations of Eucalyptus camaldulensis, Rosmarinus officinalis, and Pinus brutia extracts were considered as independent variables, and efficiency of mothproofing property through wool destruction amounts was assumed as the dependent variable. Quadratic statistical models and optimized conditions of wool protection against A. verbasci were obtained and meticulously examined. The results revealed that alcoholic extraction is an efficient method to extract the effective materials of Eucalyptus camaldulensis, Rosmarinus officinalis, and Pinus brutia, which are environmentally-friendly compounds, and that Eucalyptus camaldulensis is an excellent protection against A. verbasci, more so than the other compounds utilized in this research.
Weed management is an arduous undertaking in crop production. Integrated weed management, inclusive of the application of bioherbicides, is an emerging weed control strategy toward sustainable agriculture. In general, bioherbicides are derived either from plants containing phytotoxic allelochemicals or certain disease-carrying microbes that can suppress weed populations. While bioherbicides have exhibited great promise in deterring weed seed germination and growth, only a few in vitro studies have been conducted on the physiological responses they evoke in weeds. This review discusses bioherbicide products that are currently available on the market, bioherbicide impact on weed physiology, and potential factors influencing bioherbicide efficacy. A new promising bioherbicide product is introduced at the end of this paper. When absorbed, phytotoxic plant extracts or metabolites disrupt cell membrane integrity and important biochemical processes in weeds. The phytotoxic impact on weed growth is reflected in low levels of root cell division, nutrient absorption, and growth hormone and pigment synthesis, as well as in the development of reactive oxygen species (ROS), stress-related hormones, and abnormal antioxidant activity. The inconsistency of bioherbicide efficacy is a primary factor restricting their widespread use, which is influenced by factors such as bioactive compound content, weed control spectrum, formulation, and application method.
DOR: 98.1000/2383-1251.1398.6.151.12.2.1575.41
Extended abstract
Introduction: Due to their aggressive and competitive habits, weeds inhibit the growth of valuable plants. Interference in plants includes environmental competition and allelopathy (Autotoxicity and hetrotoxicity). In hetrotoxicity, chemical compounds released from plants are able to effect the neighboring plants. Proper management of weeds and the exploitation of their hetrotoxicity potential can reduce losses caused by weeds. This could also represent an effective step towards the reduction of the use of herbicides. Therefore, the purpose of this study was to evaluate the effect of hetrotoxicity potential of aqueous extract of various organs of Malva sylvestris L. weed on traits of germination and photosynthetic pigments of Echinochloa crus-galli L.
Material and Methods: An experiment was conducted to evaluate the effect of hetrotoxicity potential of aqueous extract of Malva sylvestris L. weed including the stem, leaf and flower as well as their mixture on traits of germination and photosynthetic pigments of Echinochloa crus-galli L. as a completely randomized design in three replications in Weeds Science Laboratory of Gonbad Kavous University in 2017. For this experiment, aerial parts of M. sylvestris were first collected at the flowering stage from Ramian field. They were subsequently separated with great care and were powdered. Then from them, 5% suspensions (weight/volume) were prepared, using distilled water. Finally, the extract of each organ of M. sylvestris was added to Petri dishes containing E. crus-galli seeds. After the 7th day, traits such as rate and percentage of germination, radical and shoot elongation, vigor index, total content of chlorophyll a and b and carotenoids were measured.
Results: The results showed that various organs of M. sylvestris and their mixture had different inhibitory effects on traits of germination and seedling length of E. crus-galli weed. The highest inhibition effects on rate and germination percentage and elongation of radical and shoot of E. crus-galli were obtained using leaf extract of M. sylvestris about 64.04, 64.37, 87.69, 62.81%. In this study, radical length is more affected under hetrotoxic compounds of various organs of M. sylvestris, as compared with shoot length. Based on the results, various organs of M. sylvestris and their mixture also have different inhibitory effects on chlorophyll and carotenoid content of E. crus-galli weed. It seems that the differential effects among different organs of M. sylvestris are a function of the threshold concentration of allelochemicals to hetrotoxic compounds of the organs, which causes various response by E. crus-galli.
Conclusion: Given the evidence for the effect of hetrotoxicity potential of various organs of M. sylvestris on traits of germination and pigments of chlorophyll and carotenoid of E. crus-galli and huge biomass generated, it is advisable to exploit allelochemical compounds of this plant as bio-herbicides.
Highlights:
1- Study of the the effect of hetrotoxic potential of Malva sylvestris weed on germination characteristics and photosynthetic pigments of Echinochloa crus-galli in Ramian field.
2- E. crus-galli weed exhibits great sensitivity to hetrotoxic compounds of various organs of M. sylvestris, especially the leaves.
3- Allelopathic characteristics of M. sylvestris weed have huge potentials for the production of bio-herbicides.
Objetivou-se avaliar a ação dos óleos essenciais de citronela (Cymbopogon nardus), capim-limão (Cymbopogon citratus), erva-cidreira (Lippia alba) e hortelã-pimenta (Mentha piperita) sobre plantas de melancia (Citrullus lanatus), feijão-carioca (Phaseolus vulgaris) e arroz (Oryza sativa). Para cada cultura foi utilizado o delineamento inteiramente casualizado em esquema fatorial com quatro repetições, em que os fatores foram quatro tipos de óleos essenciais e quatro concentrações dos óleos (0,5; 1; 2; e 4%). Dezoito dias após o plantio, as plantas foram pulverizadas com as soluções dos óleos essenciais, e 24 horas depois foi feita a avaliação de fitotoxicidade utilizando-se a escala de notas de zero (0) (ausência de fitotoxicidade) a 100 (100%) (murcha total da planta). A concentração de 2% dos óleos essenciais avaliados foi fitotóxica para as três espécies de plantas. Em plântulas de melancia o óleo de capim-limão foi o mais fitotóxico, onde nas concentrações de 2 e 4% apresentou toxicidade de 68,75 e 75%, respectivamente. O feijão foi o menos sensível aos óleos essenciais, apresentando 50% de fitotoxicidade quando submetido aos óleos de citronela e capim-limão a 4%. Ocorreu murcha e ressecamento das plantas de arroz sob 4% dos óleos de hortelã-pimenta e citronela.
The goal of this investigation was to determine the effects of allelochemicals on plant respiration that thereby may be responsible for their role in growth inhibition. We have tested the effects of juglone, quercetin, cinnamic acid, andα-pinene on respiration rates, and electron partitioning through the cytochrome and alternative respiratory pathways, by measuring on-line oxygen consumption and oxygen isotope fractionation in soybean cotyledon tissue. Cinnamic acid andα-pinene decreased the oxygen consumption rate and increased the relative partitioning of electron transport to the alternative pathway. Possible biochemical mechanisms of these effects are discussed.
Essential oils were extracted from 32 aromatic plants and evaluated for allelopathic properties. The major components of the oils were identified by gas chromatography and GC-MS. Extracts from Origanum syriacum, Micromeria fruticosa, and Cymbopogon citratus were selected for further study. The germination of several species, including wheat, was strongly inhibited by essential oils when applied at 20–80 ppm. Essential oils mixed with the top 0.5 cm of soil inhibited germination of wheat and Amaranthus seeds. This effect depended on the type of soil. The possible use of essential oils as herbicides is discussed.
Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
Volatile monoterpenes emanating from leaves of Salvia leucophylla (Labiatae) are responsible for anatomical and physiological changes occurring in herb seedlings which were exposed to the vapors. Examination of treated root tip cells from Cucumis sativus by electron microscopy revealed widespread systemic disturbances. These included the accumulation of globules which appear to be lipid in nature in the cytoplasm, a drastic reduction in the number of a variety of intact organelles including mitochondria, and a disruption of membranes surrounding nuclei, mitochondria, and dictyosomes. These effects, coupled with the effects of environmental stress, may account for the failure of herb seedlings to survive in the areas adjacent to Salvia thickets.
Because milk and milk products are highly perishable foods, high standards are required for a successful and profitable dairy industry. The milk leaving the farm must be of good nutritional and bacteriological quality and be uncontaminated by soil and chemical pollutants.
The bioassay of T. minuta and S. areira oils and their pure principal components revealed strong inhibitory activity of the root growth of Zea mays seedlings. Both T. minuta and S. areira oils treatment presented an increase in malondialdehyde values from 24 to 48 h, while the main components of the essential oils, ocimenone, alpha-pinene and limonene, presented an increase from 24 to 96 h indicating lipid peroxidation. The T. minuta essential oil had a greater inhibitory action and oxidant effect on the root of Zea mays than S. areira oil.
The leaves of Salvia leucophylla, S. mellifera, and S. apiana have been shown to contain the following terpenes: α-pinene, camphene, β-pinene, cineole, dipentene, and camphor. Such terpenes also are present in the atmosphere above macerated leaves of these species. Camphor and cineole are the most inhibitory materials and the pinenes are the least inhibitory. It is suggested that the inhibition of growth of annual grassland species in and about colonies of Salvia is due to the production of volatile terpenes, especially camphor and cineole.
Gas chromatography studies have shown that the air around Salvia leucophylla and S. mellifera (growing either in the field or in the greenhouse) contains two terpenes, apparently cineole and camphor. These terpenes are known to be more toxic than other terpenes that occur in the plants. The several terpenes of S. leucophylla are highly soluble in hard paraffin, suggesting that they are taken into the seedlings they inhibit by solution in the cutin of the mesophyll.
Prior generalizations about the ecological roles of monoterpenes may be misleading if based on the presumed insolubility of monoterpenes in water. We determined the aqueous solubility of 31 biologically active monoterpenes by gas chromatography. While hydrocarbons were of low solubility (< 35 ppm), oxygenated monoterpenes exhibited solubilities one or two orders of magnitude higher, with ranges of 155-6990 ppm for ketones and of 183-1360 ppm for alcohols. Many monoterpenes are phytotoxic in concentrations under 100 ppm, well below the saturated aqueous concentrations of oxygenated monoterpenes. Therefore, even dilute, unsaturated solutions of monoterpenes, occurring naturally in plant tissues and soil solutions, may act as potent biological inhibitors.
The hypothesis was tested that allelopathic agents released from fire-sensitive plants of the Florida scrub community deter the invasion of fireprone sandhill grasses. The structures of the constituents of four endemic scrub species,Conradina canescens, Calamintha ashei, Chrysoma pauciflosculosa, andCeratiola ericiodes, were established and their phytotoxic activity against two grasses of the sandhill was examined. Effects of the secondary metabolites from the above scrub species and their degradation products upon the germination and radicle growth of little bluestem (Schizachyrium scoparium) and green sprangletop (Leptochloa dubia), two native grasses of the Florida sandhill community, were determined. The studies included determination of the water solubility and release mechanism of terpenes and other allelopathic agents from the source plants and their aqueous transport to the target species. Some of the natural products were nontoxic until activated by light and/or oxidation after release from the source plant into the environment.
Characteristics of higher plant terpenoids that result in mediation of numerous kinds of ecological interactions are discussed as a framework for this Symposium on Chemical Ecology of Terpenoids. However, the role of terpenoid mixtures, either constitutive or induced, their intraspecific qualitative and quantitative compositional variation, and their dosage-dependent effects are emphasized in subsequent discussions. It is suggested that little previous attention to these characteristics may have contributed to terpenoids having been misrepresented in some chemical defense theories. Selected phytocentric examples of terpenoid interactions are presented: (1) defense against generalist and specialist insect and mammalian herbivores, (2) defense against insect-vectored fungi and potentially pathogenic endophytic fungi, (3) attraction of entomophages and pollinators, (4) allelopathic effects that inhibit seed germination and soil bacteria, and (5) interaction with reactive troposphere gases. The results are integrated by discussing how these terpenoids may be contributing factors in determining some properties of terrestrial plant communities and ecosystems. A terrestrial phytocentric approach is necessitated due to the magnitude and scope of terpenoid interactions. This presentation has a more broadly based ecological perspective than the several excellent recent reviews of the ecological chemistry of terpenoids.
Allelopathic inhibition typically results from the combined action of a group of allelochemicals which, collectively, interfere with several physiological processes. The objectives of this paper are to summarize research that illustrates the joint action of allelochemicals, and to provide evidence that both the amount and detrimental action of these compounds depends an the extent of associated abiotic and biotic stresses. Allelopathy is strongly coupled with other stresses of the crop environment, including insects and disease, temperature extremes, nutrient and moisture variables, radiation, and herbicides. These stress conditions often enhance allelochemical production, thus increasing the potential for allelopathic interference. In the paradigm of interactions, the data indicate that crops are more sensitive to allelopathy when moisture, temperature, or nutrient conditions are less than optimal. For example, the inhibition threshold concentration for ferulic acid to affect seedling growth was reduced with even minor moisture stress (ψ = -0.15 MPa) or a growth temperature at the higher end of the normal range for a species. Under greenhouse conditions, additive inhibition resulted from the joint action of ferulic acid with low levels of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide], atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], or trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine]. Interactions of multiple stresses in crop environments will determine the relative impact of allelopathy. Allelopathy-stress interactions also have implications for herbicide and residue management strategies, crop rotations, biological control measures, and tillage practices that can contribute to a more sustainable agriculture.
The effect of crude volatile oils from the leaves ofEucalyptus globulus andE. citriodora and the pure terpenes - cineole and limonene from these oils, (in vapour form) was studied onPhaseolus aureus, Lens esculentum, Hordeum vulgare and Avena sativa. The parameters like germination of seeds, seedling growth, values of cell survival, and content of water and chlorophyll
of the crops formed the system of bioefficacy study. The allelopathic impact of the oil vapours from the eucalypt tree becomes
evident from the negative response of the parameters studied. The impact of the E. citriodora oil vapours compared to that
ofE. globulus oil or the pure terpenes was seen to be relatively greater in almost all parameters under investigation. A strong reciprocal
correlation that exist between the concentration and the seedling growth or the water content of the crops under study supports
the dose linked allelopathic phenomenon. It is suggested that oil vapours ofEucalyptus exert their effect through impairing the respiratory as well as photosynthetic ability of the target plants.
Laboratory and greenhouse experiments were conducted to determine the herbicidal effect of plant-derived oils and to identify the active ingredient in an oil with herbicide activity. Twenty-five different oils were applied to detached leaves of dandelion in the laboratory. Essential oils (1%, v/v) from red thyme, summer savory, cinnamon, and clove were the most phytotoxic and caused electrolyte leakage resulting in cell death. Each of these essential oils in aqueous concentrations from 5 to 10% (v/v) plus two adjuvants (nonionic surfactant and paraffinic oil blend at 0.2% [v/v]) were applied to shoots of common lambsquarters, common ragweed, and johnsongrass in the greenhouse; shoot death occurred within 1 h to 1 d after application. Essential oil of cinnamon had high herbicidal activity, and eugenol (2-methoxy-4-[2-propenyl]phenol) was determined to be this oil's major component (84%, v/v). Dandelion leaf disk and whole-plant assays verified that eugenol was the active ingredient in the essential oil of cinnamon. Essential oils are extracted from plants and thus may be useful as “natural product herbicides” for organic farming systems. Nomenclature: Cinnamon, Cinnamomum zeylanicum; clove, Syzgium aromaticum; red thyme, Thymus vulgaris; summer savory, Satureja hortensis; common lambsquarters, Chenopodium album L. CHEAL; common ragweed, Ambrosia artemisiifolia L. AMBEL; dandelion, Taraxacum officinale Weber in Wiggers TAROF; johnsongrass, Sorghum halepense (L.) Pers. SORHA.
Although natural product-based discovery strategies have not been as successful for herbicides as for other pesticides or pharmaceuticals, there have been some notable successes. Phosphinothricin, the biosynthetic version of glufosinate, and bialaphos are phytotoxic microbial products that have yielded commercial herbicides. Cinmethylin, a herbicidal analogue of cineole, has been sold in Europe and Asia. The triketone herbicides are derivatives of the plant-produced phytotoxin leptospermone. These products represent only a small fraction of commercialized herbicides, but they have each introduced a novel molecular target site for herbicides. Analysis of the literature reveals that phytotoxic natural products act on a large number of unexploited herbicide target sites. The pesticide industry’s natural product discovery efforts have so far concentrated on microbially derived phytotoxins, primarily from non-pathogenic soil microbes, involving the screening of large numbers of exotic isolates. Plant pathogens usually produce potent phytotoxins, yet they have received relatively little attention. Even less effort has been made to discover plant-derived phytotoxins. Bioassay-directed isolation has been the preferred method of discovery after a producing organism is selected. This laborious approach often leads to rediscovery of known compounds. Modern tandem separation/chemical characterization instrumentation can eliminate much of this problem by identification of compounds before they are bioassayed.
The effect of four monoterpenes - citronellol, citronellal, cineole and linalool - on the germination, growth and physiology of Cassia occidentalis was investigated. All four monoterpenes reduced germination of C. occidentalis seeds but to varying extents. Citronellal and linalool completely inhibited germination beyond the concentrations of 55 and 110 μM, respectively, whereas in response to treatment of citronellol no germination was observed beyond 330 μM. Further, the growth of seedlings, measured in terms of seedling length and biomass, was also adversely affected. A reduction in chlorophyll content of the cotyledonary leaves of C. occidentalis was also noticed, indicating an adverse effect on photosynthesis. Likewise, respiratory ability of growing seeds was also impaired in response to all four monoterpenes, clearly indicating that monoterpenes affect energy metabolism. On the basis of overall phytotoxicity, potency of monoterpenes was in the order of citronellal > linalool > citronellol > cineole. The results from this study suggest that both citronellal and linalool possess strong phytotoxic potential and can thus serve as lead molecules for the synthesis of bioherbicides.
The hexane extract of the aerial part of Artemisia annua yielded three new cadinanes along with several known compounds of which five have been iso
A study was undertaken to explore the effect of volatile oils from Eucalyptus citriodora and its major constituent citronellal against two wellknown rice pathogens Rhizoctonia solani and Helminthosporium oryzae The radial growth and dry weight of both the test fungi were drastically reduced in response to the volatile oils A complete inhibition of R solani and H oryzae was observed at 10 and 20 ppm respectively Citronellal alone was found to be more effective than eucalypt oils Based on the study it was concluded that eucalypt volatile oils have potential for the suppression of phytopathogenic fungi
The volatile monoterpene analogs, 1,4-cineole and 1,8-cineole, have been identified as components of many plant essential oils, but relatively little is known about their biological activities. We compared the effects of 1,4- and 1,8-cineole on two weedy plant species by monitoring germination, mitosis, root and shoot growth, chlorophyll content, and photosynthetic efficiency. 1,4-Cineole severely inhibited growth of roots and shoots, causing cork-screw shaped morphological distortion, whereas 1,8-cineole caused a decrease in root growth and germination rates. Chlorophyll fluorescence data (yield and F
v / F
m) indicated that 1,4-cineole caused significantly higher stress (P 0.001) to photosynthesis when compared to controls. Mitotic index data showed that 1,8-cineole severely decreased (P 0.001) all stages of mitosis when compared with controls, while 1,4-cineole only caused a decrease in the prophase stage (P 0.05). Although superficially similar in structure, these two cineoles appear to have different modes of action.
The effects of four monoterpenes—camphor, eucaliptol, limonene, and -pinene—on the oxidative metabolism of mitochondria isolated from maize root (Zea mays), on maize seed germination, and on primary root growth were investigated. The effects of individual monoterpenes on respiration were variable. -Pinene concentrations of 0.05–1.0 mM stimulated respiration with a mixture of substrates composed of NADH, L-malate, succinate, and L-glutamate, and in the absence of exogenously added ADP (basal respiration). However, at concentrations higher than 1.0 mM, -pinene inhibited respiration both in the absence (basal respiration) and presence of ADP (coupled respiration). Limonene at 0.1 mM or above stimulated basal respiration and inhibited in parallel the coupled respiration. Similar effects were promoted by eucaliptol, but at a higher concentration range (1.0 mM or above). Camphor was less active. At 10 mM concentration, it caused stimulation of basal respiration but did not affect coupled respiration. In the concentration range 0.1–10.0 mM, limonene was inactive on seed germination and primary root growth. Camphor and eucaliptol did not inhibit germination but reduced fresh and/or dry weight of roots at 5.0 mM and above. -Pinene inhibited both seed germination and fresh weight of primary roots at 10.0 mM concentration. The results indicate that intact seeds and primary roots are less sensitive than isolated mitochondria. The relatively more lipophilic monoterpenes -pinene and limonene had less activity than the more water-soluble oxygenated monoterpenes camphor and eucaliptol in inhibiting seed germination and/or primary root growth, despite the fact that they had a higher activity on the oxidative metabolism of isolated mitochondria. The findings suggest that the solubility of monoterpenes may be the major factor implicated in these differences.
Cinch is a morphogenetically active herbicide that inhibits primary root growth and induces abnormal ``nodule-like'' lateral
roots on Arabidopsis thaliana seedlings. Using 200 nm Cinch, the early stages of lateral root formation occurred along the apical half of the root axis; but once emerged, they
were inhibited from further growth. Second-order lateral roots formed at the base of stunted first-order lateral roots after
5 days of Cinch treatment. Results from Cinch experiments suggested that pericycle cells are determined in the meristem to
be potential sites of lateral root formation, and the developmental transition point between emerged lateral roots and subsequent
growth is inhibited. Results using 2,4-dichlorophenoxyacetic acid and 2,3,5-triiodobenzoic acid suggest that Cinch is not
a chemical analog of auxin.
The bioassay of T. minuta and S. areira oils and their pure principal components revealed strong inhibitory activity of the root growth of Zea mays seedlings. Both T. minuta and S. areira oils treatment presented an increase in malondialdehyde values from 24 to 48 h, while the main components of the essential oils, ocimenone, α-pinene and limonene, presented an increase from 24 to 96 h indicating lipid peroxidation. The T. minuta essential oil had a greater inhibitory action and oxidant effect on the root of Zea mays than S. areira oil.
Certain essential plant oils, widely used as fragrances and flavors in the perfume and food industries, have long been reputed to repel insects. Recent investigations in several countries confirm that some plant essential oils not only repel insects, but have contact and fumigant insecticidal actions against specific pests, and fungicidal actions against some important plant pathogens. As part of an effort aimed at the development of reduced-risk pesticides based on plant essential oils, toxic and sublethal effects of some essential oil terpenes and phenols have been investigated using the tobacco cutworm (Spodoptera litura) and the green peach aphid (Myzus persicae) as model pest species. In this paper I review (i) the range of biological activities of essential oils and their constituents; (ii) their toxicity and proposed mode-of-action in insects; (iii) their potential health and environmental impacts as crop protectants; and (iv) commercialization of pesticides based on plant essential oils.
A study was conducted to assess the allelopathic effect of two volatile monoterpenes viz. cineole and citronellol on Ageratum conyzoides with a view to explore the possibility of their exploitation for future weed management. Both the monoterpenes severely affected the germination, speed of germination, seedling growth, chlorophyll content and respiratory activity. After two weeks of exposure, the weed plants wilted. Out of the two monoterpenes, cineole was more toxic in causing injury to the weed.
Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
The volatile oil extracted from the leaves of Eucalyptus citriodora showed a wide spectrum of antifungal activity.
The worldwide threat of arthropod-transmitted diseases, with their associated morbidity and mortality, underscores the need for effective insect repellents. Multiple chemical, botanical, and "alternative" repellent products are marketed to consumers. We sought to determine which products available in the United States provide reliable and prolonged complete protection from mosquito bites.
We conducted studies involving 15 volunteers to test the relative efficacy of seven botanical insect repellents; four products containing N,N-diethyl-m-toluamide, now called N,N-diethyl-3-methylbenzamide (DEET); a repellent containing IR3535 (ethyl butylacetylaminopropionate); three repellent-impregnated wristbands; and a moisturizer that is commonly claimed to have repellent effects. These products were tested in a controlled laboratory environment in which the species of the mosquitoes, their age, their degree of hunger, the humidity, the temperature, and the light-dark cycle were all kept constant.
DEET-based products provided complete protection for the longest duration. Higher concentrations of DEET provided longer-lasting protection. A formulation containing 23.8 percent DEET had a mean complete-protection time of 301.5 minutes. A soybean-oil-based repellent protected against mosquito bites for an average of 94.6 minutes. The IR3535-based repellent protected for an average of 22.9 minutes. All other botanical repellents we tested provided protection for a mean duration of less than 20 minutes. Repellent-impregnated wristbands offered no protection.
Currently available non-DEET repellents do not provide protection for durations similar to those of DEET-based repellents and cannot be relied on to provide prolonged protection in environments where mosquito-borne diseases are a substantial threat.
The method of evaluating cold injury in woody plants by the use of triphenyl tetrazolium chloride has been refined to eliminate bias associated with visual differentiation between varying degrees of tetrazolium reduction and to predict tissue survival at a later date. An advantage of the method described here is that a small amount of tissue (50-100 mg) is required; this, therefore, allows for hardiness determinations at precise locations on the plant. The high correlation between cold injury and triphenyl tetrazolium chloride reduction may be due to cofactor and substrate limitations rather than inactivation of dehydrogenases.
Root growth of Cucumis and Avena seedlings is inhibited by volatile materials produced by leaves of Salvia leucophylla, S.
apiana, and Artemisia californica. The toxic substance may be deposited when dew condenses on affected seedlings in the field.
Natural compounds from spices could replace potato sprouting inhibitors
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Vaughn S F. 1991. Natural compounds from spices could
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Essential oils as allelochemicals: research advances in Greece
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Allelopathic Properties of Eucalyptus
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Leaf diffusibility changes of bean and sunflower plants treated with essential oil vapours
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