12 research outputs found

    Relationship between Chemical Composition and Nematicidal Activity of Different Essential Oils

    No full text
    In this study, the relationship between nematicidal activity and chemical composition of ten essential oils (EOs) from different plant species was investigated both in in vitro assays on juveniles (J2) and eggs of the root-knot nematode Meloidogyne incognita and in experiments on tomato in soil infested by M. incognita. Nematode J2 were exposed for 4, 8 or 24 h to 0.78–100 μg mL−1 concentrations of each EO, whereas 24, 48 or 96 h exposures to 250, 500 and 1000 μg mL−1 solutions were tested on M. incognita egg masses. Treatments with 50, 100 or 200 μg kg soil rates of each EO were applied in the experiment on potted tomato. The highest nematicidal potential resulted for the C. verum EO, as highly toxic to both M. incognita J2 and eggs and strongly suppressive on nematode multiplication on tomato roots. The infestation of M. incognita on tomato roots was also strongly reduced by the EOs from E. citriodora and S. aromaticum, both highly toxic to M. incognita J2 but less active on nematode eggs. Adversely, R. graveolens EO strongly inhibited the egg hatch but was limitedly toxic to the infective J2. Chemical composition of the EOs was determined by GC-FID and GC-MS. The ten EOs showed a very different chemical composition in terms of major phytochemicals, with one or two dominant components totally amounting up to 85%. The structure–activity relationship based on the main phytochemicals identified in the assayed EOs and their nematicidal effects on M. incognita was also discussed. Results from this study confirmed that the selection of suitable EO raw materials can lead to the formulation on new effective nematicidal products. Keywords: essential oils; bioactive components; nematicidal activity; Meloidogyne incognita

    Nematicidal activity of Echinacea species on the root‑knot nematode Meloidogyne incognita

    No full text
    Echinacea species are reported for a large content of bioactive compounds, but their effects on phytoparasitic nematodes are still unknown. This study comparatively investigated the in vitro activity of chemically characterized extracts from E. angustifolia, E. pallida and E. purpurea on juveniles and eggs of the root-knot nematode Meloidogyne incognita. Suppressiveness of soil amendments with Echinacea plant biomasses was also investigated against M. incognita on tomato in potting mixes. More than 50% juvenile mortality occurred after a 48-h exposure to a 500 μg mL−1 solution of all Echinacea extracts, as well as more than 50% of M. incognita eggs did not hatch after a 1-week exposure to the same concentration of E. angustifolia extracts. Nematode multiplication on tomato roots was always significantly reduced in soil amended with all Echinacea biomasses, as well as almost all treatments also resulted in a significant tomato growth increase. Polar compounds such as echinacoside and chicoric acid were the main components of the extracts from Echinacea aerial parts, whereas apolar components as alkamides prevailed in root extracts. Data confirmed the potential of the three Echinacea species, mainly E. angustifolia, for the formulation of new formulates for a sustainable nematode management

    Biostimulants for Plant Growth Promotion and Sustainable Management of Phytoparasitic Nematodes in Vegetable Crops

    No full text
    The parasitism of root-knot nematodes, Meloidogyne spp., can cause heavy yield losses to vegetable crops. Plant biostimulants are often reported for a side-suppressive effect on these pests and many commercial products are increasingly included in sustainable nematode control strategies. Source materials of most biostimulants derived from plant or seaweed raw materials were documented for a reliable suppression of root-knot nematode species, whereas the suppressiveness of microbial biostimulants was found largely variable, as related to the crop and to environmental factors. Chitosan-based biostimulants were also stated for a variable phytonematode suppression, though clearly demonstrated only by a few number of studies. In a preliminary experimental case study, four commercial biostimulants based on quillay extract (QE), sesame oil (SO), seaweeds (SE), or neem seed cake (NC) were comparatively investigated for their effects against the root-knot nematode M. incognita on potted tomato. Soil treatments with all the four biostimulants resulted in a significant reduction of nematode eggs and galls on tomato roots, though NC and SO were significantly more suppressive than QE or SE. In addition, almost all biostimulant treatments also resulted in a significant improvement of tomato growth compared to the non-treated control. These preliminary results seem to confirm the literature data and clearly indicate the potential role of biostimulants for a safe nematode management both in organic and integrated crop systems

    Nematicidal potential of Taraxacum officinale

    No full text
    This study was aimed to investigate the activity of the Asteraceae species Taraxacum officinale against the root-knot nematode Meloidogyne incognita. Leaf and root extracts of T. officinale were tested in vitro at a range of 62.5–1000 and 250–1000 Î¼g mL−1 concentrations on nematode juveniles and eggs, respectively, whereas treatments with 10–40 g kg−1 soil rates of dry leaf and root T. officinale biomass were applied to soil infested by M. incognita in greenhouse experiments on potted tomato. Peak 36 and 50% juvenile mortality and 14.8 and 23.8% egg hatchability reduction were recorded at the maximum concentration of leaf and root extracts, respectively. Soil treatments with T. officinale leaf and root material strongly suppressed nematode multiplication and gall formation on tomato roots and significantly increased plant growth. Chicoric acid and 3-O- and 3,5-di-O-caffeoylquinic acid were found to be the main components of leaf and root extract, respectively, and proved, as the total hydroalcoholic extracts from T. officinale leaf and root material, for an antioxidant activity. Data from this study indicate the suitability of plant materials from T. officinale for a potential formulation of nematicidal products to include in sustainable nematode management strategies

    Correction to: Nematicidal potential of Taraxacum officinale (Environmental Science and Pollution Research, (2018), 25, 30, (30056-30065), 10.1007/s11356-018-2903-4)

    No full text
    The original publication of this paper contains a mistake. Data on Table 1 under TR and TL column have been interchanged: that is compounds 1-12 and their amounts refer to TL; compounds 1-8 and related amounts refer to TR (see Fig. 1). Consequently, for quantitation of compounds in paragraph "Chemical analysis" refer to this errata corrige. Correct table is shown in this paper. (Table presened.)

    Attività biocida degli oli essenziali di Monarda su nematodi fitoparassiti di interesse agrario

    No full text
    Introduzione. I nematodi fitoparassiti sono tra le più pericolose avversità delle piante agrarie a causa delle forti perdite di produzione causate ad un gran numero di colture di interesse economico. La scomparsa dal mercato di gran parte dei più efficaci nematocidi di sintesi ha incentivato la ricerca di mezzi di lotta più sostenibili, tra cui prodotti biocidi di origine vegetale quali gli oli essenziali (OE). L’attività nematocida degli OE e dei loro principali componenti è ampiamente documentata in letteratura e tali sostanze potrebbero costituire delle potenziali materie prime per la formulazione di nuovi nematocidi a maggiore sostenibilità ambientale. Gli OE di specie di Monarda potrebbero costituire degli ottimi candidati per la formulazione di tali prodotti, visto che per i principali costituenti monoterpenici di tali OE è già stata documentata un’elevata tossicità nei confronti di nematodi galligeni del genere Meloidogyne. Scopi. Obiettivo principale del programma di studi in vitro ed in vivo oggetto della presentazione è stato quello di caratterizzare l’attività nematocida degli OE di due specie di Monarda, M. didyma e M. fistulosa, sul nematode galligeno Meloidogyne incognita. Materiali e Metodi. Nelle prove in vitro larve infettive o masse d’uova di M. incognita sono state esposte per differenti tempi ad un range di concentrazioni degli OE di M. didyma e M. fistulosa e dei loro principali componenti. L’effetto dei trattamenti sulla mobilità e vitalità delle larve è stato determinato mediante osservazione microscopica, mentre la potenziale attività ovicida dei due OE è stata valutata sottoponendo le masse d’uova trattate ad un test di schiusura. L’attività in vivo è stata determinata mediante trattamento con differenti concentrazioni degli OE di M. didyma e M. fistulosa di un terreno fortemente infestato da M. incognita, in cui è stato successivamente eseguito un saggio su pomodoro in vaso. Risultati. Entrambi gli OE sono risultati altamente tossici verso le larve di M. incognita anche a concentrazioni molto ridotte, così come hanno determinato una significativa riduzione delle percentuale di schiusura delle uova. Tutti i trattamenti al terreno con le soluzioni acquose dei due OE in prova hanno determinato una significativa riduzione della infestazione di M. incognita sulle radici di pomodoro. Conclusioni. Gli OE di M. didyma e M. fistulosa hanno evidenziato un’elevata attività nei confronti di M. incognita e, pertanto, sono da considerare degli interessanti materiali per la formulazione di nuovi prodotti per una gestione sostenibile degli attacchi di nematodi fitoparassiti

    Prodotti nematocidi di origine vegetale in orticoltura

    No full text
    Phytoparasitic nematodes cause heavy annual yield losses and thus can be considered among the most dangerous pests for a number of vegetable crops. Management of these parasites has been traditionally based on synthetic pesticides, but because of their high environmental impact we need to find more sustainable products to control nematodes. Biocidal compounds, naturally occurring as products of plant secondary metabolism, may represent a large source of biocompatible nematicides. This review briefly reports the main botanical groups and plant secondary metabolites with a nematicidal potential, as well as the most effective techniques for their exploitation. Nematotoxic volatile products, such as isothiocyanates and nitriles released from the degradation of glucosinolates present in tissues of Brassicaceae plants or cyanide deriving from the cyanogenic glucosides of some Sorghum species can be exploited for nematode control through the incorporation of fresh or dry plant material into the soil. Commercial liquid formulations based on seed oils from neem (Azadirachta indica Juss.) or sesame (Sesamum indicum L.) or water extracts from quillay (Quillaja saponaria Molina) bark or tagetes (Tagetes erecta L.) are already available for soil treatments over the crop cycle and/or seedling root dipping before t ransplant . Many plant species from Asteraceae family, such as Calendula spp., Chrysanthemum spp. and Artemisia spp., have been also demonstrated to be a potential source of nematicidal products for the control of root-knot and cyst phytonematodes economically relevant to vegetable crops. Green manures or crop rotations with indigenous (Medicago spp., Trifolium spp., Vicia spp., Lupinus albus) and tropical (Mucuna spp., Crotalaria spp) Leguminosae species, as well as soil amendments with their formulated plant biomass, have been reported to achieve a satisfactory nematode suppression, due to the high content of bioactive metabolites (phenols, alkaloids, alcohols and mainly saponins) of these plants. Essential oils from a wide range of aromatic and medicinal plants and their volatile bioactive components (terpenes, aldheydes, ketones and more) have been largely acknowledged for a high nematicidal activity, both in vitro studies and as soil treatments in water solution or by fumigation. Full exploitation of the high nematicidal potential of these products is strictly related to the development of technical formulations suitable to delay the release and degradation of active components into the soil. Phenolic compounds, such as terpenoids, flavonoids, tannins and coumarins, can also play a relevant role in the formulation of innovative nematicidal products. Commercial formulations of chestnut tannins demonstrated to be highly suppressive to root-knot nematode infestation. Nematicidal effect were reported also for soils amendments with tannin-rich plant materials. Coumarins are among the main agents of the strong nematicidal activity reported for plants from genus Ruta, such as R. graveolens and R. chalepensis. Susceptible of exploitation could be also the nematicidal properties reported for the pyrrolizidine and steroidal alkaloids from many Asteraceae, Leguminosae and Solanaceae species. Review of literature data confirmed the effectiveness of plant products for a sustainable phytonematode management, also due to the low environmental persistance and toxicity to humans, animal and plants of thei r act ive compounds. Multicomponent activity of most plant products also avoids the raising of nematode resistance, as frequently reported for repeated treatments with synthetic nematicides

    SOIL SOLARIZATION FOR A SUSTAINABLE MANAGEMENT OF NEMATODES AND WEEDS IN VEGETABLE CROPS IN SOUTHERN ITALY

    No full text
    Soil solarization has been known as an effective method for the integrated management of phytoparasitic nematodes and weeds since many years. The interest in this technique has been renewed following the withdrawal of most chemical nematicides and herbicides available on the market. This technique is particularly suitable to vegetable crop systems of Southern Italy, where summer climate is more suitable to raise soil temperatures up to values sufficiently high to cause irreversible damages to nematodes and weed seeds. The effectiveness of repeated soil solarization treatments, as well as of different solarizing materials, on root-knot nematodes, weeds and crop yield was assessed in the greenhouse studies overviewed in this work. Two different trials were carried out in plastic-greenhouse conditions at Metaponto, Southern. In the first experiment solarization was performed for one, two or three consecutive years in a soil infested by the root-knot nematode Meloidogyne javanica. In the second experiment, four different solarizing plastic materials, EVA, LDPE, ultrathin coextruded (EVA + LDPE) and corn starch-based biodegradable film, were comparatively evaluated for their solarizing effectiveness. Nonsolarized soil was used as a control in both experiments. In each trial, tomato or melon crop were carried out after the solarization treatment. Crop yield, nematode infestation parameters and weeds were recorded at the end of each crop cycle. Application of soil solarization throughout two or three consecutive years significantly increased crop yield and quality and strongly suppressed nematodes and weeds compared either to non-solarized soil and a single heating treatment. Different plastic films satisfactorily controlled root-knot nematodes and weeds and improved crop yield, with no significant differences among them. In conclusion, these studies confirmed soil solarization as an effective tool for a sustainable and cost-saving management of root-knot nematodes and weeds in greenhouse crop systems of Southern Italy. Use of ecocompatible solarizing plastic films, such as biodegradable and co-extrusive ultra-thin films can furtherly improve the environmental safety of this technique
    corecore