The Experts below are selected from a list of 4827 Experts worldwide ranked by ideXlab platform
Scott A Merkle - One of the best experts on this subject based on the ideXlab platform.
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Light quality treatments enhance somatic Seedling Production in three southern pine species
Tree Physiology, 2006Co-Authors: Scott A Merkle, Paul M. Montello, Bruce L. Upchurch, Dale R. SmithAbstract:Summary Embryogenic cultures of loblolly pine (Pinus taeda L.), slash pine (Pinus elliottii Engelm.), longleaf pine (Pinus palustris Mill.) and slash pine × longleaf pine hybrids were initiated from immature seeds on an initiation medium containing 13.57 µM 2,4-dichlorophenoxyacetic acid and 2.22 µM benzylaminopurine. Embryogenic cultures proliferated and somatic embryos developed, matured and germinated following a modified protocol and media originally developed for radiata pine (Pinus radiataD. Don.) somatic Seedling Production. A discrete, light-sensitive pre-germination stage and a later germination (radicle emergence) stage were identified by the differential response of somatic embryos to light of different wavelengths. Different light quality treatments were applied during the pre-germination and germination steps, using cool white fluorescent bulbs or light-emitting diodes (LEDs), or both. In general, red wavelengths provided by LEDs during these steps resulted in higher frequencies of somatic embryo germination (up to 64%) and conversion (up to 50%), longer tap roots and more first-order lateral roots than the standard cool white fluorescent treatments or treatment with blue wavelengths from LEDs. In addition, exposure to red light allowed germination of somatic embryos of some clones that failed to produce germinants under fluorescent light. Germination and conversion were further enhanced by sequential application of cool white fluorescent light and red light, resulting in up to 100% germination and conversion in one experiment. Longleaf pine somatic embryos were especially responsive to the light quality treatments, resulting in the first report of somatic Seedling Production for this species.
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enhancement of american chestnut somatic Seedling Production
Plant Cell Reports, 2005Co-Authors: Gisele M De Andrade, Scott A MerkleAbstract:Somatic embryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic Seedling Production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic Seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic Seedling Production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somatic embryogenesis for mass clonal propagation of the tree.
Gisele M De Andrade - One of the best experts on this subject based on the ideXlab platform.
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enhancement of american chestnut somatic Seedling Production
Plant Cell Reports, 2005Co-Authors: Gisele M De Andrade, Scott A MerkleAbstract:Somatic embryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic Seedling Production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic Seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic Seedling Production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somatic embryogenesis for mass clonal propagation of the tree.
F Tittarelli - One of the best experts on this subject based on the ideXlab platform.
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the challenge of peat substitution in organic Seedling Production optimization of growing media formulation through mixture design and response surface analysis
PLOS ONE, 2015Co-Authors: F G Ceglie, M. A. Bustamante, Mouna Ben Amara, F TittarelliAbstract:Peat replacement is an increasing demand in containerized and transplant Production, due to the environmental constraints associated to peat use. However, despite the wide information concerning the use of alternative materials as substrates, it is very complex to establish the best materials and mixtures. This work evaluates the use of mixture design and surface response methodology in a peat substitution experiment using two alternative materials (green compost and palm fibre trunk waste) for transplant Production of tomato (Lycopersicon esculentum Mill.); melon, (Cucumis melo L.); and lettuce (Lactuca sativa L.) in organic farming conditions. In general, the substrates showed suitable properties for their use in Seedling Production, showing the best plant response the mixture of 20% green compost, 39% palm fibre and 31% peat. The mixture design and applied response surface methodology has shown to be an useful approach to optimize substrate formulations in peat substitution experiments to standardize plant responses.
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utilisation of citrus compost based growing media amended with trichoderma harzianum t 78 in cucumis melo l Seedling Production
Bioresource Technology, 2010Co-Authors: Ruben Lopezmondejar, F Tittarelli, Agustina Bernalvicente, Stefano Canali, F Intrigiolo, J A PascualAbstract:Abstract Two citrus composts (C1: composed of 40% citrus wastes, 20% sludge obtained from a citrus industry waste-water treatment facility and 40% green residues; C2: composed of 60% citrus wastes and 40% green residues, and no sludge) and their water extracts amended with Trichoderma harzianum T-78 ( T. harzianum T-78) were assayed in order to verify if these composts could act as a partial substitute for peat-based growing media as well as enhance suppressiveness against Fusarium wilt in the Production of melon ( Cucumis melo L.) Seedlings at greenhouse nurseries. Over a 43-day growth cycle of melon Seedlings, measurements were taken of the nutriactive effect (the capability of a substrate to express additional and/or synergistic nutritional and biostimulating effects), the pathogen incidence (percentage of fresh weight loss of melon plants grown on treatments infected with Fusarium oxysporum with respect to the same treatment without inoculation of the phytopathogen) and the trend of the T. harzianum T-78 population. A nutriactive effect was observed in the tested citrus compost-based growing media (96% and 112% plant weight increase with respect to peat for C1Th and C2Th, respectively). Pathogen incidence was significantly lower in C2Th than peat (12% compared to 33%), while no difference was observed in C1Th. The T. harzianum T-78 population showed a significant decrease at the first sampling time compared to the initial quantity (from 10 6 to 10 5 CFU g −1 ), but later recovered over time. These results demonstrate that the combination of citrus compost and T. harzianum T-78 can be a viable alternative to peat and can minimise the application of chemicals necessary to control Fusarium wilt in greenhouse nurseries for melon Seedling Production.
Nestor Gregorio - One of the best experts on this subject based on the ideXlab platform.
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observations of forestry Seedling Production systems in thailand and vietnam
Improving the Effectiveness and Efficiency of the Philippines Tree Nursery Sector, 2010Co-Authors: Stephen R Harrison, Nestor GregorioAbstract:Visits to forestry agencies and Seedling nurseries in Thailand and Vietnam revealed an impressive level of progress in regard to both industrial and small-scale forestry. In both countries, reforestation is accorded high priority, the government is a major player in nursery Seedling Production, and a high level of technology is used in producing Seedlings. Universities also play an active role in forestry Seedling Production. The visit provided valuable lessons for Seedling Production systems in the Philippines, including information about the roles of government versus private nurseries and about Seedling quality and nursery accreditation.
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The role of systems modelling in forestry Seedling Production research in the Philippines
2010Co-Authors: Carl Smith, Nestor GregorioAbstract:This paper discusses the role that systems modelling has played in the planning and design of the ACIAR Seedling Enhancement Project and the key lessons learned from the application of systems modelling. The project used a Bayesian network to integrate available knowledge about the tree Seedling Production system in Leyte, the Philippines. This model was used to identify areas of poor performance within the tree Seedling Production systems and to test potential improvements that could be made to systems performance through interventions and research projects. The use of the model highlighted the need for interventions at three key areas: forest nursery management training and accreditation, the establishment of tree seed centres, and the establishment of a database of nursery operators. These interventions are described in the paper. The key lessons learned from the application of a systems model in the ACIAR Seedling Enhancement Project are: undertake systems modelling early on in a project to ensure that research targets systemic failures rather than symptoms; involve stakeholders and managers within the systems modelling so that the interventions identified meet the needs of takeholders; use appropriate modelling tools that allow stakeholders to participate in model development and scenario analysis; build the capacity of local researchers to undertake systems modelling so that they can support local managers in decision making; and use system modelling throughout the project to plan, implement and review the success of research.
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A Critical Overview of Forestry Seedling Production Policies and Practices in Relation to Smallholder Forestry in Developing Countries
Small-scale Forestry, 2008Co-Authors: Steve Harrison, Nestor Gregorio, John HerbohnAbstract:This paper reviews forestry Seedling Production systems in South-east and East Asia and identifies problems with respect to Seedling quality, Seedling distribution and financial sustainability, and measures which have been adopted or advocated to improve performance in this sector. The paper draws in particular on experience in a series of research projects on smallholder forestry in the Philippines. Some observations are also drawn from the following papers in this combined special issue of Small-scale Forestry . It is found that a mix of public and private sector models are adopted for forestry Seedling Production, between and even within countries. Often nurseries are set up to provide Seedlings for a government-directed expansion in tree planting, and have difficulty surviving once the initial planting purpose is completed. Private nurseries often lack resources, and depend on contracts to supply Seedlings for financial viability. Demand tends to be highest for fast-growing species (often exotics), fruit trees, and ornamentals in the case of urban nurseries. Government policies typically favour quantity over quality of the Seedlings produced. Considerable scope exists for adopting best or at least improved management practice in Seedling nurseries.
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enhancing tree Seedling supply to smallholders in leyte province philippines an evaluation of the Production system of government nursery sector and support to smallholder tree farmers
Small-scale Forestry, 2008Co-Authors: Nestor Gregorio, S R Harrison, John HerbohnAbstract:A decentralized Seedling Production is regarded as the most effective means of providing smallholders with planting materials. However, the sustainability of smallholder nursery operation is constrained by several factors, including the limited availability of germplasm, lack of technical skills and low Seedling demand low viability of Seedling market. The government nursery sector could complement the weaknesses of the smallholder nursery group but government nurseries are not operating effectively to enhance the availability of high quality Seedlings of a wide species base for smallholder forestry. Seedling Production in government nurseries is quantity-orientated with low emphasis on the Production of high quality planting materials. Germplasm used in Seedling Production is mostly collected from unselected sources and Seedlings produced are mostly of low physical quality. The species selection in government nurseries is heavily based on the availability of germplasm which resulted in the Production of a few species which are commonly raised on private nurseries. The duplication of species of most Seedlings raised in government nurseries with those produced in private nurseries and the far distance of government nurseries from the villages has resulted in low uptake of Seedlings by smallholder tree farmers. For the government nursery sector to become more effective in providing support in the present paradigm of decentralized seeding Production, a change from its Production system and a broadening of the role it plays is needed. The social mobilization on Seedling Production as a scheme of implementing the Green Philippines Program has led the Department of Environment and Natural Resources to acknowledge the Seedling Production activity of private individual and communal nursery groups. This can be an opportunity for organizing the private and government nursery sectors to promote the operational effectiveness of the overall forest nursery industry.
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Seedling Production Systems for Smallholder Forestry Development: Local Practices versus National Policies in the Philippines
2008Co-Authors: Steve Harrison, Nestor Gregorio, John Herbohn, Augustin MercadoAbstract:The tree Seedling nursery sector in the Philippines is influenced by a number of national level policies affecting the number and type of species produced. Policies favour high-volume Production of a limited range of mostly exotic species, and research indicates that Seedlings are often of low physical and genetic quality. Local knowledge on best species for sites is not being communicated to people planting. A project funded by the Australian Centre for International Agricultural Research is investigating measures to improve the performance and effectiveness of the forestry Seedling Production system in Leyte and Mindanao in the Philippines. Seedlings are produced by government agencies, in community forestry projects and by individual private operators; the main customers are smallholder tree farmers. Communities and private individuals quickly set up nurseries when there is a demand for Seedlings, but these nurseries tend to be ephemeral and lack financial sustainability. While large nurseries offer opportunities for economies of scale, small nurseries operate on a low cost basis, and are more widely distributed, and their Seedlings are more accessible to smallholders, who lack transport facilities. Small private nurseries, while having limited access to new technology, often produce Seedlings of quality similar to government and community nurseries. However, they require assistance in access to high-quality germplasm and training in improved seed Production technology, to play a greater role in expansion of plantation forestry. This paper reports survey findings on Seedling Production systems, and examines the link between national level policies and local level practices.
John Herbohn - One of the best experts on this subject based on the ideXlab platform.
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A Critical Overview of Forestry Seedling Production Policies and Practices in Relation to Smallholder Forestry in Developing Countries
Small-scale Forestry, 2008Co-Authors: Steve Harrison, Nestor Gregorio, John HerbohnAbstract:This paper reviews forestry Seedling Production systems in South-east and East Asia and identifies problems with respect to Seedling quality, Seedling distribution and financial sustainability, and measures which have been adopted or advocated to improve performance in this sector. The paper draws in particular on experience in a series of research projects on smallholder forestry in the Philippines. Some observations are also drawn from the following papers in this combined special issue of Small-scale Forestry . It is found that a mix of public and private sector models are adopted for forestry Seedling Production, between and even within countries. Often nurseries are set up to provide Seedlings for a government-directed expansion in tree planting, and have difficulty surviving once the initial planting purpose is completed. Private nurseries often lack resources, and depend on contracts to supply Seedlings for financial viability. Demand tends to be highest for fast-growing species (often exotics), fruit trees, and ornamentals in the case of urban nurseries. Government policies typically favour quantity over quality of the Seedlings produced. Considerable scope exists for adopting best or at least improved management practice in Seedling nurseries.
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enhancing tree Seedling supply to smallholders in leyte province philippines an evaluation of the Production system of government nursery sector and support to smallholder tree farmers
Small-scale Forestry, 2008Co-Authors: Nestor Gregorio, S R Harrison, John HerbohnAbstract:A decentralized Seedling Production is regarded as the most effective means of providing smallholders with planting materials. However, the sustainability of smallholder nursery operation is constrained by several factors, including the limited availability of germplasm, lack of technical skills and low Seedling demand low viability of Seedling market. The government nursery sector could complement the weaknesses of the smallholder nursery group but government nurseries are not operating effectively to enhance the availability of high quality Seedlings of a wide species base for smallholder forestry. Seedling Production in government nurseries is quantity-orientated with low emphasis on the Production of high quality planting materials. Germplasm used in Seedling Production is mostly collected from unselected sources and Seedlings produced are mostly of low physical quality. The species selection in government nurseries is heavily based on the availability of germplasm which resulted in the Production of a few species which are commonly raised on private nurseries. The duplication of species of most Seedlings raised in government nurseries with those produced in private nurseries and the far distance of government nurseries from the villages has resulted in low uptake of Seedlings by smallholder tree farmers. For the government nursery sector to become more effective in providing support in the present paradigm of decentralized seeding Production, a change from its Production system and a broadening of the role it plays is needed. The social mobilization on Seedling Production as a scheme of implementing the Green Philippines Program has led the Department of Environment and Natural Resources to acknowledge the Seedling Production activity of private individual and communal nursery groups. This can be an opportunity for organizing the private and government nursery sectors to promote the operational effectiveness of the overall forest nursery industry.
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Seedling Production Systems for Smallholder Forestry Development: Local Practices versus National Policies in the Philippines
2008Co-Authors: Steve Harrison, Nestor Gregorio, John Herbohn, Augustin MercadoAbstract:The tree Seedling nursery sector in the Philippines is influenced by a number of national level policies affecting the number and type of species produced. Policies favour high-volume Production of a limited range of mostly exotic species, and research indicates that Seedlings are often of low physical and genetic quality. Local knowledge on best species for sites is not being communicated to people planting. A project funded by the Australian Centre for International Agricultural Research is investigating measures to improve the performance and effectiveness of the forestry Seedling Production system in Leyte and Mindanao in the Philippines. Seedlings are produced by government agencies, in community forestry projects and by individual private operators; the main customers are smallholder tree farmers. Communities and private individuals quickly set up nurseries when there is a demand for Seedlings, but these nurseries tend to be ephemeral and lack financial sustainability. While large nurseries offer opportunities for economies of scale, small nurseries operate on a low cost basis, and are more widely distributed, and their Seedlings are more accessible to smallholders, who lack transport facilities. Small private nurseries, while having limited access to new technology, often produce Seedlings of quality similar to government and community nurseries. However, they require assistance in access to high-quality germplasm and training in improved seed Production technology, to play a greater role in expansion of plantation forestry. This paper reports survey findings on Seedling Production systems, and examines the link between national level policies and local level practices.