167 research outputs found

    On-farm evaluation of integrated pest management of thrips and whiteflies in herb cuttings in Ethiopia : report to the Ministry of Agriculture and Rural Development

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    Integrated Pest Management reduces the use of chemicals and therewith the impact of greenhouse horticulture on the environment. It improves working conditions and enables access of Ethiopian products on the world market. In response to such concerns the Ethiopian Horticulture Producers and Exporters Organization (EPHEA) has taken the initiative to develop a Code of Practice, of which Integrated Pest Management forms an integral part. The development of this Integrated Pest Management approach is supported through the Ethiopia-Netherlands Horticulture Partnership Programme

    Saprophytic and predacious abilities in Arthrobotrys oligospora in relation to dead and living root-knot nematodes

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    Un isolat d'#Arthrobotrys oligospora formant des hyphes adhésifs réagit nettement à l'état de sa source de nourriture, en ce cas des juvéniles de deuxième stade (J2) de #Meloidogyne hapla, vivants, inactivés ou morts. Les J2 rendus immobiles par chauffage et uniquement capables de mouvoir leur stylet sont entourés par des structures annulaires identiques à celles produites dans le cas de J2 parfaitement mobiles ; cependant ces structures sont surtout présentes autour de la région céphalique, demeurée seule mobile. Le champignon pénètre dans les J2 morts mais restés intacts obtenus après traitement aux rayons gamma ou à l'acide de sodium - à travers la cavité buccale à l'aide de structures en tire-bouchons. Les J2 morts ayant une cuticule altérée sont totalement recouverts par de fins hyphes végétatifs. A l'évidence, l'isolat de #A. oligospora$ passe de l'un à l'autre type de prise de nourriture suivant la source de cette dernière. Les modes saprophytique et prédateur n'apparaissent pas s'exclure l'un l'autre. Le fait de placer les J2 morts au contact d'une colonie fongique avant d'y placer des J2 vivants n'affecte pas la formation et l'attache des hyphes trophiques sur ces derniers ; mais un jour après l'addition des J2 vivants, la proportion de ces juvéniles pourvus de structures annulaires augmente par rapport au nombre total de juvéniles lorsque placés au même moment. Le développement des hyphes trophiques chez les J2 morts est retardé en présente de J2 vivants. Ces résultats contredisent l'affirmation courante suivant laquelle de mauvaises conditions de croissance saprophytique constituent un préliminaire obligé pour un mode de nutrition prédatrice. (résumé d'auteur

    Functional agro biodiversity in Dutch arable farming: results of a three year pilot

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    A pilot on 400 ha of Dutch arable farms during 2004-2007 perennial grassy field margins and functional annual flower strips were created on potato and wheat fields. Monitoring information on pests and natural enemies was directly communicated to the farmers to support pest management decisions. Due to the increasing numbers of natural enemies and the gradually reducing peak densities of aphids, the farmers could refrain from insecticide applications against aphids in these crops. The pilot has yielded great public awareness on possibilities for functional agro biodiversity in arable crops

    Trapping of root-knot nematodes by the adhesive hyphae-forming fungus Arthrobotrys oligospora

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    The present study addresses the ecology of a particular isolate of Arthrobotrys oligospora (CBS 289.82) in relation to its efficacy in controlling the root-knot nematode, Meloidogyne hapla.This isolate was selected because it differs from most nematode-trapping fungi in that it captures nematodes with adhesive hyphae without having to form complex trapping devices. This characteristic may make it a very useful biological control agent. An attempt was made to gain insight into the factors controlling its capture ability.In vitro experiments demonstrated that the A. oligospora (CBS 289.82) isolate was very effective in capturing M.hapla and M. incognita, compared to the ability of other fungi with other trapping devices. Mobile juveniles were all caught by the hyphae within one hour and in some cases attachment occurred within the very first contact (chapter 2).Electron microscopic observations revealed that attachment of juveniles of Meloidogyne spp. to hyphae is mediated by a layer of extracellular material, about 0.1 gm thick, on the hyphae (chapter 3). Such a layer was never observed in hyphae of fungal cultures to which nematodes were not added, suggesting that its presence depends on an interaction of the fungus with the nematode. The attachment of Meloidogyne second-stage juveniles was not affected by temperatures between 5 and 3O°C. However, at 15°C ring structure development and growth of trophic hyphae were strongly hampered, which suggest that under prevailing soil temperatures in temperate regions, ring structure development and growth of trophic hyphae may proceed slowly whereas trapping would continue to occur (chapter 4).Furthermore, the nutritional conditions during growth of the fungus did not correlate with the rapidity of nematode-hypha attachment. The results also provide evidence that the trapping ability of the isolate tested continued for over more than 70 days (chapter 4).Arthrobotrys oligospora (CBS 289.82) covered dead, ruptured nematodes with a dense mycelium, whereas dead but otherwise intact nematodes were penetrated through the buccal cavity by a corkscrew-like structure and were subsequently colonized by trophic hyphae. Colonization of living second-stage juveniles by trophic hyphae following attachment and penetration was faster than colonization of dead second-stage juveniles. The addition of dead juveniles to a fungal colony prior to the addition of living juveniles did not affect attachment or the development of trophic hyphae through the live juveniles. However, one day after the addition of live juveniles, the proportion of live nematodes with ring structures was higher than when living and dead juveniles were added at the same time. The development of trophic hyphae in dead second-stage juveniles was delayed in the presence of live second-stage juveniles. The results refute the commonly held assumption that poor possibilities for saprophytic growth are a prerequisite for the formation of trapping devices and the predacious mode of feeding in the fungus (chapter 5).An important quality of fungi as potential biological control agents is their ability to form mycelium and capture structures in the soil at the place where their activity is desirable.The establishment and capture activity of this isolate in a simple microcosm system at 20°C, was compared to that of other fungi from the Dactylaria -complex. Direct microscopic observations in microcosms confirmed the attachment of mobile juveniles of M. hapla to hyphae of A. oligospora (chapter 6). Application of about 30 mm hyphal fragments of A. oligospora (CBS 289.82) per gram soil resulted in 100-170 in of hyphae per gram oven-dry soil at 20°C within 12 days, a reduction of 90% in the number of living nematodes of M. hapla within one day after addition and the extermination of the nematodes within 10 days. In non-sterilized soil, the hyphae reached a total length of 10 in per gram oven-dry soil. This amount of hyphal mass was sufficient to reduce the number of nematodes by 70% as compared to the control within 10 days after nematodes were added to the soil. At 13°C, similar results were obtained. Even at low densities, this isolate is effective. Notwithstanding their ability to form the most extensive mycelial mats of all fungi tested and despite the fairly large amounts of M. hapla added, nematode capture in both adhesive ring-forming fungi A. conoides (CBS 265.83) and A. oligospora (ATCC 24927) was zero or low. This supports other observations that the adhesive ring-forming fungi are inefficient (chapter 6).In chapter 7 the results on the ability of A. oligospora (CBS 289.82) to capture root-knot nematodes presented in the previous chapters are evaluated. The mechanism of nematode trapping is also discussed from the perspective of screening nematode-trapping fungi and using the adhesive hyphae-forming fungi as biological control agents

    A Research and Development plan for the introduction of Integrated Pest Management in the Ethiopian Rose Sector

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    All parties involved agree upon the advantages of Integrated Pest Management (IPM) in Ethiopian rose production. There should be no a priori limitation to the introduction of IPM including biological control. Transport facilities, willingness by farmers, consumers’ zero-tolerance to chemical residues, positive experiences in other countries, and growing cooperation between growers, researchers and government are some of the enabling factors. However, the introduction will not be a matter of simply changing pesticide use, or of adopting a technology. The key factor will be the growing confidence of growers to be involved in and contribute to the process of developing a more sustainable rose production in Ethiopia

    Repel (plaag) en retain (natuurlijke vijand) in aardbei : verslag trips-mulch-natuurlijke vijanden experimenten in 2013

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    Een aantal tripssoorten vormen zeer ernstige plagen in een zeer brede groep van voor Nederland economische belangrijke gewassen zoals groentegewassen waaronder aardbei, prei, ui en kool maar ook in de bloementeelt. Chemische bestrijding is door het niet meer toelaten van breedwerkende middelen zoals mesurol en resistentieontwikkeling in trips steeds moeilijker. Het doel van dit onderzoek is het vaststellen van de efficiency van een pest-repel en natural enemy retain (Legarrea et al., 2012) strategie in aardbei d.m.v. mulch (foto-selectief materiaal/fysieke barriere) (zie ook Larentzaki et al., 2008) en inzet van roofwantsen. In dit rapport worden de resultaten van 2013 gepresenteerd van drie veldexperimenten die in een geïntegreerde lay-out bij het proefbedrijf Vredepeel zijn uitgevoerd waarbij belangrijke vragen zijn: • wat zijn de effecten van witte mulch, Orius majusculus en de combinatie op de populatie opbouw van trips populaties in aardbei • en in welke mate verschilt dit van onbehandeld, gangbaar (inzet chemische middelen) en het loslaten van de roofmijt Amblyseius montdorensi
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