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| Registros recuperados: 117 | |
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| Rasmussen, Ilse A.; Holst, Niels. |
| We developed a simple model to predict seed production from seedling density and estimated its six parameters for Chenopodium album and Papaver rhoeas from literature data, supplemented with field data on P. rhoeas seed production in Denmark. Parameter values were specified by their expected ranges rather than just point estimates, which enabled us to determine the expected ranges of seed production at given seedling densities. The model will be incorporated into a larger model framework presented earlier for a more complete description of annual weed seedbank dynamics in a crop rotation. We found the seed production (y) of P. rhoeas to be larger than reported earlier from UK; the relation to weed biomass (x) per m2 was curvilinear, y=6015∙x0.8153 seeds... |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2003 |
URL: http://orgprints.org/3434/1/3434.doc |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| Danish experiments with cereal-based organic crop rotations have shown that the short-term results (the first course, up to four years after conversion) are different from those obtained in the longer-term (the second course, fifth to eighth year after conversion). Yield gain from use of manure increased from the first to the second course on a sandy soil, but decreased on loamier soils. Yield gain from leguminous catch crops increased from the first to the second course in a crop rotation without grass-clover. Some of these effects were caused by buffering effects of the grass-clover, other effects were caused by changes in soil fertility over time. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop combinations and interactions. |
| Ano: 2006 |
URL: http://orgprints.org/7680/1/Rasmussen_IA_et_al.doc |
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| Rasmussen, Ilse A.. |
| Three field experiments were carried out in organically grown winter wheat in Denmark. The treatments were sowing time (normal or late sowing) and false seedbed, row width (12 cm and 24 cm) and weed control method (untreated, mechanical weed control (weed harrowing at 12 cm supplemented with inter-row hoeing at 24 cm), and herbicide weed control). Weed biomass in mid-summer was greatest on plots sown at the normal sowing time (compared to delayed sowing) and was reduced by mechanical or chemical weed control (compared with untreated plots). Row width alone had no influence on weed biomass, but in the experiment with high weed pressure, the more intensive mechanical weed control used at a row width of 24 cm reduced weed biomass. Normal sowing time tended to... |
| Tipo: Journal paper |
Palavras-chave: Cereals; Pulses and oilseeds Weed management Crop husbandry. |
| Ano: 2004 |
URL: http://orgprints.org/3932/1/rasmussen.pdf |
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| Holst, Niels; Riemens, Marleen; Rasmussen, Ilse A.. |
| Perennial herbs can be difficult to manage because of their underground storage organs which live sheltered from observation and control. In this paper, we describe the development of a population dynamics model for two perennial weeds, Cirsium arvense and Tussilago farfara. The model is physiologically based and includes plant growth and development, and mowing as a control option. Model performance was compared with field data from monospecific stands of C. arvense in Denmark and Netherlands and of T. farfara in Denmark. Finally, optimal mowing strategies were explored with the model. |
| Tipo: Journal paper |
Palavras-chave: Weed management. |
| Ano: 2012 |
URL: http://orgprints.org/20650/4/20650.pdf |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| The plant protection carried out in the Danish crop rotation experiment is described. These measures can be quite different in the different systems. While mechanical weed control can be carried out in systems without catch crops, it is not possible to do so in systems with catch crops without affecting the establishment of the catch crop. The occurrence of weeds, pests and diseases is recorded, and the results are described. Since the results are only from the two first years of the experiments, it is not possible to conclude anything about the crop rotations as such. There are however differences related to the other experimental treatments in the experiment: the presence or absence of catch crops and manure. Only in very few cases are the differences... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Weed management Crop health; Quality; Protection Cereals; Pulses and oilseeds. |
| Ano: 1999 |
URL: http://orgprints.org/247/1/DARCOF1.PDF |
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| Olesen, Jørgen E.; Rasmussen, Ilse A.; Askegaard, Margrethe. |
| For at belyse mulighederne for at dyrke mere økologisk korn til modenhed, blev der i 1996/97 anlagt et økologisk sædskifteforsøg på fire lokaliteter i Danmark: · Jyndevad (JB1) i Sønderjylland, · Foulum (JB4) i Midtjylland · Flakkebjerg (JB6) på Sjælland · Holeby (JB7) på Lolland Sædskifterne repræsenterer systemer med forskellige andele af korn og kvælstoffikserende afgrøder. De har været afprøvet med fire forskellige kombinationer af fangafgrøder (uden og med) og husdyrgødning (uden og med). Det giver en bred vifte af informationer om de enkelte systemers produktionsevne og stabilitet. |
| Tipo: Newspaper or magazine article |
Palavras-chave: Cereals; Pulses and oilseeds. |
| Ano: 2003 |
URL: http://orgprints.org/1812/1/E0070.doc |
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| Rasmussen, Ilse A.; Holst, Niels; Madsen, Kathrine Hauge. |
| Seeds of genetically modified (GM) crops remaining in the field after harvest may later emerge as volunteers. These can affect the purity of subsequently harvested crops and cause an uncontrolled flow of GM pollen into the agro-ecosystem. Management strategies that reduce these long-term effects of GM crops include (1) minimizing the input of GM seeds into the soil, (2) preventing proliferation by volunteers and (3) fast depletion of the soil GM seed bank. Formulation of such strategies requires knowledge of the biology of the GM plant (seed loss at or before harvest, seed survival, germination and emergence rates, reproduction, etc.) and of the effect of management practices on the different life stages. Of the GM crops considered for cultivation in... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Crop health; Quality; Protection Weed management. |
| Ano: 2003 |
URL: http://orgprints.org/3934/1/3934.doc |
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| Olesen, Jørgen E.; Askegaard, Margrethe; Rasmussen, Ilse A.. |
| A crop rotation experiment was established in 1996/97 at three locations representing differ-ent soil types and climates. Three factors were tested: i) crop rotation with different propor-tions of N2-fixing crops, ii) with and without a catch crop, and iii) with and without animal manure. A green manure crop increased yields in the following cereal crops, but at the rota-tional level, total yields were larger in crop rotations without a green manure crop. There were positive effects of animal manure and catch crops on yield. However, except for the coarse sandy soil, the yield effects of catch crops and animal manure decreased over time when a grass-clover green manure was included in the rotation. The problems with perennial weeds increased over time... |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover Cereals; Pulses and oilseeds Weed management. |
| Ano: 2005 |
URL: http://orgprints.org/7873/1/7873.pdf |
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| Rasmussen, Ilse A.; Askegaard, Margrethe; Olesen, Jørgen E.. |
| In 1997 a crop rotation experiment was initiated at three sites in Denmark. The objective of the experiment was to explore the possibilities for both short-term and long-term increases in organic cereal production through manipulation of crop rotation design on different soil types. The experiment included three factors (proportion of grass-clover in the rotation, catch crops and manure application) in a randomised factorial design. The main indicators measured in the experiment were crop yield, nutrient leaching and weeds. The crop rotation experiment has shown significant effects of location, crop rotation, catch crops and manure on yields, weed infestation, soil fertility and nutrient losses (Olesen et al., 2002; Schjønning et al., 2004; Askegaard et... |
| Tipo: Book chapter |
Palavras-chave: Nutrient turnover; Crop combinations and interactions; Weed management; Composting and manuring. |
| Ano: 2006 |
URL: http://orgprints.org/10000/1/10000.pdf |
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| Registros recuperados: 117 | |
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