The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Abdelhamid El Mousadik - One of the best experts on this subject based on the ideXlab platform.
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Aridity or low temperatures: What affects the diversity of plant-parasitic nematode communities in the Moroccan argan relic forest?
Applied Soil Ecology, 2016Co-Authors: Thierry Mateille, Johannes Tavoillot, Bernard Martiny, Ewa Dmowska, Zyna Winiszewska, Zahra Ferji, Fouad Msanda, Abdelhamid El MousadikAbstract:Farming activities that are likely to induce the development of emerging pests increasingly disturbs the Argan Biosphere in Morocco. Considering that plant-parasitic nematodes strongly contribute to the decrease in plant growth production, a survey was conducted in the Argan Biosphere in order to assess nematode diversity and distribution. It was established that the parasitic nematofauna was rich, with 70 species belonging to 34 genera and 12 families. Species with high plant decay potential belonging to Longidoridae, Heteroderidae, Hoplolaimidae, Meloidogynidae, Paratylenchidae and Pratylenchidae are present in the argan forest. Telotylenchus sp., Paratylenchus microdorus and Paratylenchus veruculatus, Xiphinema italiae and Xiphinema pachtaicum (virus-transmitting nematodes), and Helicotylenchus crassatus are the most dominant species. Populations of root-knot (Meloidogyne spp.) and lesion (Pratylenchus spp.) nematodes are also present. Climate forces have driven the structuration of the argan forest to topoclimatic landscapes that led the diversity of the plant-parasitic nematodes communities. The north-south typology of the arid climate affects the richness and the taxonomic and functional diversity of nematodes, while the west-east temperature typology mainly affects the abundance of nematodes, especially of colonizing species. The emergence of plant-parasitic nematode problems as a consequence of intensive agroforestry or argan orchard development is considered.
Sandra A. Easley - One of the best experts on this subject based on the ideXlab platform.
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Vertical Distribution of Pratylenchus spp. in Silt Loam Soil and Pacific Northwest Dryland Crops.
Plant disease, 2008Co-Authors: Richard W. Smiley, J. G. Sheedy, Sandra A. EasleyAbstract:Dryland field crops in the Pacific Northwest United States are commonly produced in silt loams infested by the root-lesion nematodes Pratylenchus neglectus and P. thornei. Soils at 30 sites in Oregon were sampled from 0 to 120 cm depth to examine the vertical distribution of these Pratylenchus spp. Both species were distributed through entire soil profiles of all cropping systems. Populations were generally greatest in the surface 30 cm, but sometimes high populations were detected at depths greater than 45 cm. Sampling to 30 cm depth allowed detection of more than 50% of the population in most sites, while sampling to 45 cm depth yielded more than 75% of the population in over 75% of the sites evaluated. Therefore, soil samples should be collected to 30 to 45 cm depth to accurately estimate populations of Pratylenchus spp. in dryland crops produced on silt loams in the Pacific Northwest. Populations of Pratylenchus spp. were found to be related to the most recently planted crop, with populations after barley, after wheat, and during summer fallow being detected in ascending order.
D. Erickson - One of the best experts on this subject based on the ideXlab platform.
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Pratylenchus neglectus, P. thornei, and Paratylenchus hamatus Nematodes Causing Yield Reduction to Dryland Peas and Lentils in Idaho.
Plant Disease, 2008Co-Authors: Evi Riga, L. D. Porter, H Mojtahedi, D. EricksonAbstract:In June 2006, stunted and chlorotic plants were observed in large patches in two 40.5-ha fields of dryland peas (Pisum sativum) in Latah County, Idaho, which resulted in 90 and 75% crop loss. In the same region, a 121.4-ha field of dryland lentils (Lens culinaris) also had plants showing poor growth, wilting, and yellowing in large patches, which resulted in 40% crop loss. Two species of lesion nematodes (Pratylenchus neglectus and P. thornei) and one species of pin nematode (Paratylenchus hamatus) were extracted from rhizosphere soil and the roots of symptomatic plants from these fields. In a subsequent survey of seven dryland pea fields, under cv. Columbian, in Latah and Nez Perce counties and one dryland pea field, under cv. Small Sieve, in Latah County, plant samples had means of 551 and 2,178 mixed species of lesion nematodes per gram of dry root, respectively. Plant samples from 12 lentil fields in Latah County, six planted with cv. Red Chief and six with cv. Pardina, had means of 279 and 987 mixed ...
Johannes Hallmann - One of the best experts on this subject based on the ideXlab platform.
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Plant parasitic nematodes on soybean in expanding production areas of temperate regions
Journal of Plant Diseases and Protection, 2018Co-Authors: Ahmed Elhady, Holger Heuer, Johannes HallmannAbstract:Soybean [Glycine max (L.) Merrill] is the most economically important legume in the world. One of the main yield limiting factors is plant parasitic nematodes, such as Heterodera glycines, Meloidogyne incognita or Pratylenchus brachyurus, which cause severe damage in the main production regions of soybean around the world. For Germany, soybean is still a relatively newly cultivated crop and so far, no information about the occurrence and damage potential of plant parasitic nematodes on soybean is available for this region. For a successful growth of soybean, farmers need to understand, which plant parasitic nematodes can be of risk for soybean production. Within this respect, the objective of this study was to describe the spectrum and abundance of plant parasitic nematodes occurring on soybean under temperate conditions in Germany. Data were collected from farmer fields and experimental sites throughout Germany between 2014 and 2015. Representative soil samples were taken before planting and shortly after harvest. Plant parasitic nematodes were extracted by centrifugal floatation, and identified morphologically to genus level. Selected individuals of Pratylenchus were further identified to species level based on COI gene sequences. The population dynamics of Pratylenchus penetrans and co-occurring plant parasitic nematodes on soybean cv. Merlin was studied in microplots. Finally, the impact of P. penetrans affecting nitrogen fixation by the symbiotic bacterium Bradyrhizobium japonicum was studied in greenhouse experiments. Our findings indicated that Pratylenchus is widely spread in soybean fields in Germany. Main species were P. neglectus and P. crenatus and to a lesser extent P. penetrans. In the microplot experiment, nematode multiplication was highest for P. penetrans, followed by Rotylenchus robustus and Paratylenchus projectus. Infection of soybean by P. penetrans significantly reduced nitrogen fixation as indicated by lower numbers of bacteroids and reduced concentration of ureides In conclusion, Pratylenchus spp. are considered to be the most threatening plant parasitic nematodes for soybean production under the temperate conditions of Germany.
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Nematode dynamics under minimum tillage
2015Co-Authors: Johannes Hallmann, Jan Henrik Schmidt, Maria R. FinckhAbstract:Agriculture has transformed over the past centuries dramatically to become highly dependent on non-renewable fossil fuels, synthetic fertilizers and plant protection agents. This often occurs at the cost of soil degradation and soil food web disturbance. Future agriculture must not only be productive but also provide ecosystem services such as carbon sequestration, pest and disease suppression, nutrient cycling and water storage to become sustainable in the long-term. Sustainability is especially fostered by reduced tillage and the presence of a permanent layer of plant residues. Under such conditions, soil compaction is reduced, soil structure improved, water infiltration enhanced, soil organic content increased and microbial activity stimulated. However, continuous soil cover, especially associated with permanent growth of plants, might also enhance plant-parasitic nematode densities due to permanent food supply. The effect of minimum tillage on nematode dynamics was studied within the EU-funded project “Optimizing subsidiary crop applications in rotations”. The rotation consisted of clover-grass, winter wheat, cover crop, and potato. The following treatments were studied: Plough versus minimum tillage, white clover versus subterranean clover as undersown crops in winter wheat, vetch versus a 1:4 mix of fodder radish and black oats as cover crop following winter wheat, and with and without 5t DM ha-1 compost application. Initially, the field was infested with Helicotylenchus, Meloidogyne, Paratylenchus, Pratylenchus and Tylenchorhynchus. Pratylenchus and Helicotylenchus increased under wheat and Meloidogyne was supported by white clover and subterranean clover as undersown crops. Population densities of all nematode taxa declined during the following catch crop and potato. There was no difference in nematode population dynamics between plough versus minimum tillage, nor between compost versus no compost. Results will be discussed considering the recent literature.
Thierry Mateille - One of the best experts on this subject based on the ideXlab platform.
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Aridity or low temperatures: What affects the diversity of plant-parasitic nematode communities in the Moroccan argan relic forest?
Applied Soil Ecology, 2016Co-Authors: Thierry Mateille, Johannes Tavoillot, Bernard Martiny, Ewa Dmowska, Zyna Winiszewska, Zahra Ferji, Fouad Msanda, Abdelhamid El MousadikAbstract:Farming activities that are likely to induce the development of emerging pests increasingly disturbs the Argan Biosphere in Morocco. Considering that plant-parasitic nematodes strongly contribute to the decrease in plant growth production, a survey was conducted in the Argan Biosphere in order to assess nematode diversity and distribution. It was established that the parasitic nematofauna was rich, with 70 species belonging to 34 genera and 12 families. Species with high plant decay potential belonging to Longidoridae, Heteroderidae, Hoplolaimidae, Meloidogynidae, Paratylenchidae and Pratylenchidae are present in the argan forest. Telotylenchus sp., Paratylenchus microdorus and Paratylenchus veruculatus, Xiphinema italiae and Xiphinema pachtaicum (virus-transmitting nematodes), and Helicotylenchus crassatus are the most dominant species. Populations of root-knot (Meloidogyne spp.) and lesion (Pratylenchus spp.) nematodes are also present. Climate forces have driven the structuration of the argan forest to topoclimatic landscapes that led the diversity of the plant-parasitic nematodes communities. The north-south typology of the arid climate affects the richness and the taxonomic and functional diversity of nematodes, while the west-east temperature typology mainly affects the abundance of nematodes, especially of colonizing species. The emergence of plant-parasitic nematode problems as a consequence of intensive agroforestry or argan orchard development is considered.
