The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform
U. M.e. Didon - One of the best experts on this subject based on the ideXlab platform.
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Competition between Six Spring Barley (Hordeum vulgare ssp. vulgare L.) Cultivars and Two Weed Flora in Relation to Interception of Photosynthetic Active Radiation
Biological Agriculture & Horticulture, 2002Co-Authors: U. M.e. Didon, Margareta L. HanssonAbstract:ABSTRACT The aim of the study was to characterize the crop responses of six contrasting barley (Hordeum vulgare ssp. vulgare L.) Cultivars and their weed suppression ability on two different weed flora, a natural weed flora and a Sinapis alba (L.) weed flora, and also to characterize the development of light interception profiles over time of the barley Cultivars. One field experiment was conducted each year from 1997 to 1999 in an organic farming system SE of Uppsala, Sweden. The experiment included weed free stands and weed stands, as well as crop-weed stands. Differences between weed suppression ability of the Cultivars was consistent over years and the two different weed flora. Cultivar Svani was the most Competitive Cultivar, followed by Filippa. The most Competitive Cultivars were also the Cultivars that transmitted least PAR through the canopy. The differences between Cultivars in penetration of light through the canopy were most apparent during the tillering and stem elongation stage at the soil s...
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Variation Between Barley Cultivars in Early Response to Weed Competition
Journal of Agronomy and Crop Science, 2002Co-Authors: U. M.e. DidonAbstract:An experiment was conducted with three spring barley (Hordeum vulgare ssp. vulgare L.) Cultivars of contrasting Competitiveness to identify variations in their early Competitive response to weed competition and to study canopy architecture and growth development at the early stages of Cultivar growth. The aim was also to investigate whether differences in shoot morphology, growth development and Competitive response could explain the differences in Competitive ability against weeds. The barley Cultivars were grown outdoors in boxes either in monoculture or in a mixture with white mustard (Sinapis alba L.) as a model weed. The experiment was run until the barley Cultivars were in the stem elongation stage. The varieties with strong to medium Competitive ability against weeds shortened the time of emergence in the presence of S. alba in contrast to the least Competitive Cultivar. The results also indicated that spring barley Cultivars with strong Competitive ability against weeds have an early stem extension as a response to weed competition and a low Competitive response. Morphological traits, namely large length of the two first internodes, long main shoot in the tillering stage and a small leaf angle, may be important traits in competition for light. Variation bei Gerstenkultivaren in einer Fruhreaktion auf Unkrautkonkurrenz Es wurde ein Experiment mit drei Sommergerstensorten (Hordeum vulgare ssp. vulgare L.) durchgefuhrt, um unterschiedliche Konkurrenzstarke in der fruhen Reaktion gegenuber Unkrautkonkurrenz zu bestimmen und die Bestandesoberflachenarchitektur und das Wachstum der fruhen Stadien der Kultivare zu bestimmen. Ziel war es nachzuweisen, ob Unterschiede in der Sprossmorphologie, der Wachstumsentwicklung und der Konkurrenzreaktion die Unterschiede in der Konkurrenzstarke gegen Unkraut beeinflussen konnen. Die Gerstenkultivare wurden im Freien in Gefasen sowohl in Monokultur als auch in Mischungen mit Senf (Sinapis alba L.) als ein Modellunkraut aufgezogen. Das Experiment wurde bis zu dem Zeitpunkt, an dem die Gerstenkultivare schosten, durchgefuhrt. Die Sorten mit starker bis mittlerer Konkurrenzkraft gegenuber Unkraut wiesen eine kurze Auflaufzeit in Gegenwart von S. alba auf; das stand im Gegensatz zu den weniger konkurrenzstarken Kultivaren. Die Ergebnisse weisen auserdem darauf hin, dass Sommergerstenkultivare mit einer starken Konkurrenzfahigkeit gegenuber Unkrautern ein fruhes Langenwachstum als Reaktion auf die Unkrautkonkurrenz und eine geringe Konkurrenzempfindlichkeit aufweisen. Morphologische Eigenschaften wie grose Lange der beiden ersten Internodien, lange Hauptsprossachsen in der Schossphase und geringe Blattwinkel konnen wichtige Eigenschaften in der Konkurrenz um Licht sein.
François Lelièvre - One of the best experts on this subject based on the ideXlab platform.
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Role of summer dormant perennial grasses as intercrops in rainfed Mediterranean vineyards.
Crop Science, 2010Co-Authors: Florence Volaire, François LelièvreAbstract:ABSTRACTGrass swards are increasingly used in vineyards to improve ecosystem function, reduce vine vigor, and enhance grape ( Vitis vinifera L.) qual-ity. In Mediterranean rainfed vineyards, the use of intercropping has been constrained because of excessive competition for water with the vine over summer. We aimed to test Cultivars of Mediterranean forage grasses with a range of summer dormancy, which confers low competi-tiveness for water and high persistence. A 4-yr experiment compared a bare soil control and three perennial grass Cultivars as interrows in a vineyard: orchardgrass ( Dactylis glomerata L.) ‘Kasbah’ and ‘Bacchus’ and tall fescue [ Lolium arundinaceum (Schreb.) Darbysh . ] ‘Centurion’. In the spring of 2006, Centurion had extracted water to the 150-cm depth, whereas neither orchardgrasses had extracted water beyond the 120-cm depth. In the summers of 2006 and 2007, Centurion used 30 to 50 mm more of the soil water reserve in the 0- to 150-cm soil layer than the bare soil control. Vine predawn leaf water potential, vine leaf area index (LAI), and biomass of pruned shoot and of vine fruit were also sig-nifi cantly affected by intercrops. The best inter-crop was the least Competitive Cultivar, Kasbah, because of its low biomass production and com-plete summer dormancy. Bacchus is not summer dormant and was the least persistent. Centurion was the most Competitive because of its deep root system and incomplete summer dormancy. The results raise the needs for breeding a larger range of adapted Cultivars for intercropping rain-fed Mediterranean vineyards.F. Volaire and F. Lelievre, INRA, UMR SYSTEM, 2 place Viala, 34060 Montpellier, Cedex 1, France. Received 15 Jan. 2010. *Cor-responding author (volaire@supagro.inra.fr).
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Role of summer dormant perennial grasses as intercrops in rainfed Mediterranean vineyards
Crop Science, 2010Co-Authors: Florence Volaire, François LelièvreAbstract:Grass swards are increasingly used in vineyards to improve ecosystem function, reduce vine vigor, and enhance grape (Vitis vinifera L.) quality. In Mediterranean rainfed vineyards, the use of intercropping has been constrained because of excessive competition for water with the vine over summer. We aimed to test Cultivars of Mediterranean forage grasses with a range of summer dormancy, which confers low Competitiveness for water and high persistence. A 4-yr experiment compared a bare soil control and three perennial grass Cultivars as interrows in a vineyard: orchardgrass (Dactylis glomerate L.) 'Kasbah' and 'Bacchus' and tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] 'Centurion'. In the spring of 2006, Centurion had extracted water to the 150-cm depth, whereas neither orchardgrasses had extracted water beyond the 120-cm depth. In the summers of 2006 and 2007, Centurion used 30 to 50 mm more of the soil water reserve in the 0- to 150-cm soil layer than the bare soil control. Vine predawn leaf water potential, vine leaf area index (LAI), and biomass of pruned shoot and of vine fruit were also significantly affected by intercrops. The best intercrop was the least Competitive Cultivar, Kasbah, because of its low biomass production and complete summer dormancy. Bacchus is not summer dormant and was the least persistent. Centurion was the most Competitive because of its deep root system and incomplete summer dormancy. The results raise the needs for breeding a larger range of adapted Cultivars for intercropping rainfed Mediterranean vineyards
Jim Hanan - One of the best experts on this subject based on the ideXlab platform.
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a canopy architectural model to study the Competitive ability of chickpea with sowthistle
Annals of Botany, 2008Co-Authors: Szahrahosseini Cici, S W Adkins, Jim HananAbstract:† Background and Aims Improving the Competitive ability of crops is a sustainable method of weed management. This paper shows how a virtual plant model of competition between chickpea (Cicer arietinum) and sowthistle (Sonchus oleraceus) can be used as a framework for discovering and/or developing more Competitive chickpea Cultivars. † Methods The virtual plant models were developed using the L-systems formalism, parameterized according to measurements taken on plants at intervals during their development. A quasi-Monte Carlo light-environment model was used to model the effect of chickpea canopy on the development of sowthistle. The chickpea– light environment– sowthistle model (CLES model) captured the hypothesis that the architecture of chickpea plants modifies the light environment inside the canopy and determines sowthistle growth and development pattern. The resulting CLES model was parameterized for different chickpea Cultivars (viz. ‘Macarena’, ‘Bumper’, ‘Jimbour’ and ‘99071-1001’) to compare their Competitive ability with sowthistle. To validate the CLES model, an experiment was conducted using the same four chickpea Cultivars as different treatments with a sowthistle growing under their canopy. † Results and Conclusions The growth of sowthistle, both in silico and in glasshouse experiments, was reduced most by ‘99071-1001’, a Cultivar with a short phyllochron. The second rank of Competitive ability belonged to ‘Macarena’ and ‘Bumper’, while ‘Jimbour’ was the least Competitive Cultivar. The architecture of virtual chickpea plants modified the light inside the canopy, which influenced the growth and development of the sowthistle plants in response to different Cultivars. This is the first time that a virtual plant model of a crop – weed interaction has been developed. This virtual plant model can serve as a platform for a broad range of applications in the study of chickpea– weed interactions and their environment.
Florence Volaire - One of the best experts on this subject based on the ideXlab platform.
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Role of summer dormant perennial grasses as intercrops in rainfed Mediterranean vineyards.
Crop Science, 2010Co-Authors: Florence Volaire, François LelièvreAbstract:ABSTRACTGrass swards are increasingly used in vineyards to improve ecosystem function, reduce vine vigor, and enhance grape ( Vitis vinifera L.) qual-ity. In Mediterranean rainfed vineyards, the use of intercropping has been constrained because of excessive competition for water with the vine over summer. We aimed to test Cultivars of Mediterranean forage grasses with a range of summer dormancy, which confers low competi-tiveness for water and high persistence. A 4-yr experiment compared a bare soil control and three perennial grass Cultivars as interrows in a vineyard: orchardgrass ( Dactylis glomerata L.) ‘Kasbah’ and ‘Bacchus’ and tall fescue [ Lolium arundinaceum (Schreb.) Darbysh . ] ‘Centurion’. In the spring of 2006, Centurion had extracted water to the 150-cm depth, whereas neither orchardgrasses had extracted water beyond the 120-cm depth. In the summers of 2006 and 2007, Centurion used 30 to 50 mm more of the soil water reserve in the 0- to 150-cm soil layer than the bare soil control. Vine predawn leaf water potential, vine leaf area index (LAI), and biomass of pruned shoot and of vine fruit were also sig-nifi cantly affected by intercrops. The best inter-crop was the least Competitive Cultivar, Kasbah, because of its low biomass production and com-plete summer dormancy. Bacchus is not summer dormant and was the least persistent. Centurion was the most Competitive because of its deep root system and incomplete summer dormancy. The results raise the needs for breeding a larger range of adapted Cultivars for intercropping rain-fed Mediterranean vineyards.F. Volaire and F. Lelievre, INRA, UMR SYSTEM, 2 place Viala, 34060 Montpellier, Cedex 1, France. Received 15 Jan. 2010. *Cor-responding author (volaire@supagro.inra.fr).
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Role of summer dormant perennial grasses as intercrops in rainfed Mediterranean vineyards
Crop Science, 2010Co-Authors: Florence Volaire, François LelièvreAbstract:Grass swards are increasingly used in vineyards to improve ecosystem function, reduce vine vigor, and enhance grape (Vitis vinifera L.) quality. In Mediterranean rainfed vineyards, the use of intercropping has been constrained because of excessive competition for water with the vine over summer. We aimed to test Cultivars of Mediterranean forage grasses with a range of summer dormancy, which confers low Competitiveness for water and high persistence. A 4-yr experiment compared a bare soil control and three perennial grass Cultivars as interrows in a vineyard: orchardgrass (Dactylis glomerate L.) 'Kasbah' and 'Bacchus' and tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] 'Centurion'. In the spring of 2006, Centurion had extracted water to the 150-cm depth, whereas neither orchardgrasses had extracted water beyond the 120-cm depth. In the summers of 2006 and 2007, Centurion used 30 to 50 mm more of the soil water reserve in the 0- to 150-cm soil layer than the bare soil control. Vine predawn leaf water potential, vine leaf area index (LAI), and biomass of pruned shoot and of vine fruit were also significantly affected by intercrops. The best intercrop was the least Competitive Cultivar, Kasbah, because of its low biomass production and complete summer dormancy. Bacchus is not summer dormant and was the least persistent. Centurion was the most Competitive because of its deep root system and incomplete summer dormancy. The results raise the needs for breeding a larger range of adapted Cultivars for intercropping rainfed Mediterranean vineyards
S W Adkins - One of the best experts on this subject based on the ideXlab platform.
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a canopy architectural model to study the Competitive ability of chickpea with sowthistle
Annals of Botany, 2008Co-Authors: Szahrahosseini Cici, S W Adkins, Jim HananAbstract:† Background and Aims Improving the Competitive ability of crops is a sustainable method of weed management. This paper shows how a virtual plant model of competition between chickpea (Cicer arietinum) and sowthistle (Sonchus oleraceus) can be used as a framework for discovering and/or developing more Competitive chickpea Cultivars. † Methods The virtual plant models were developed using the L-systems formalism, parameterized according to measurements taken on plants at intervals during their development. A quasi-Monte Carlo light-environment model was used to model the effect of chickpea canopy on the development of sowthistle. The chickpea– light environment– sowthistle model (CLES model) captured the hypothesis that the architecture of chickpea plants modifies the light environment inside the canopy and determines sowthistle growth and development pattern. The resulting CLES model was parameterized for different chickpea Cultivars (viz. ‘Macarena’, ‘Bumper’, ‘Jimbour’ and ‘99071-1001’) to compare their Competitive ability with sowthistle. To validate the CLES model, an experiment was conducted using the same four chickpea Cultivars as different treatments with a sowthistle growing under their canopy. † Results and Conclusions The growth of sowthistle, both in silico and in glasshouse experiments, was reduced most by ‘99071-1001’, a Cultivar with a short phyllochron. The second rank of Competitive ability belonged to ‘Macarena’ and ‘Bumper’, while ‘Jimbour’ was the least Competitive Cultivar. The architecture of virtual chickpea plants modified the light inside the canopy, which influenced the growth and development of the sowthistle plants in response to different Cultivars. This is the first time that a virtual plant model of a crop – weed interaction has been developed. This virtual plant model can serve as a platform for a broad range of applications in the study of chickpea– weed interactions and their environment.