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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Modelling The Effect Of A Variable Light Extinction Coefficient And Leaf Dispersion On Light Partitioning Between Species In A Grass-Clover Mixture, M Nassiri, A Elgersma
Modelling The Effect Of A Variable Light Extinction Coefficient And Leaf Dispersion On Light Partitioning Between Species In A Grass-Clover Mixture, M Nassiri, A Elgersma
IGC Proceedings (1997-2023)
Light partitioning in a grass-clover mixture was studied using a general competition model. The model assumes a fixed extinction coefficient (k) and no leaf dispersion. This was compared with modelling the effect of different k of both species over height as well as the effect of type of leaf dispersion. These new assumptions led to a better estimation of the light partitioning between both species. For grass the effect of variable k and leaf dispersion was similar and in both cases the total absorbed light was lower than under default conditions. For clover the new assumptions led to a higher …
Allocation Of Carbon-14 To Roots Of Different Ages In Perennial Ryegrass (Lolium Perenne L.), C Matthew, W D. Kemball
Allocation Of Carbon-14 To Roots Of Different Ages In Perennial Ryegrass (Lolium Perenne L.), C Matthew, W D. Kemball
IGC Proceedings (1997-2023)
The objective of this study was to provide information on how current photosynthate allocated to the root system in perennial ryegrass (Lolium perenne L.) is distributed among individual roots at differing nodal positions. Mature single ryegrass tillers were transplanted in September 1993 to glass house pots and three months later four of the plants were supplied with 14CO2. Individual roots from these radioactively-labeled plants were identified according to their nodal position on the tiller axis and amount of radiocarbon in each root quantified for root tip segments and for the remainder of the root axis. Similar plants were destructively …
Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass, K F.M. Reed, S G. Clark, W M. Feely
Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass, K F.M. Reed, S G. Clark, W M. Feely
IGC Proceedings (1997-2023)
Over four years, sowing perennial ryegrass (Lolium perenne) with a range of subterranean clover (“sub clover”, Trifolium subterraneum) cultivars was found to reduce the yield of clover per se by 31% and increase pasture yield by 11%. For one high-producing experimental variety, the presence of grass did not reduce clover yield (P<0.001). Clover yield in monoculture plots was poorly correlated with that measured in mixed swards (r = 0.44), but clover yield (± grass) was correlated with total herbage yield (r = 0.94). Clover seed yield was not reduced by the presence of grass. However, in year 2 - but not in the establishment year - grass reduced seed weight. Irrespective of grass treatment, the new late maturing cultivar, Leura outyielded the other commercial cultivars (P<0.05). Enfield and Enfield x Daliak crosses set the most seed and regenerated with a greater density than other cultivars (P<0.05) - apart from Leura. It was concluded that the winter-active, late maturing cultivar, Leura, will compete most successfully with perennial ryegrass.
Breeding Morphogenetic Traits To Match Genotypes To Their Utilization, L Hazard, M Betin, M Ghesquiere
Breeding Morphogenetic Traits To Match Genotypes To Their Utilization, L Hazard, M Betin, M Ghesquiere
IGC Proceedings (1997-2023)
A divergent selection for lamina length was done from natural populations of perennial ryegrass. Tested in a multi-site experiment in France, the short-leaved perennial ryegrass was more productive under simulated grazing and less productive under infrequent cutting than the long-leaved perennial ryegrass. Matching cultivars to their management is possible by selecting for morphogenetic traits. However, our results suggest the range of adaptation to different managements of perennial ryegrass cultivars could be extended by increasing their phenotypic plasticity.
Mitochondrial Genome Polymorphism In Lolium Perenne, Y Shimamoto, Y Tominaga, M Sato, T Mikami
Mitochondrial Genome Polymorphism In Lolium Perenne, Y Shimamoto, Y Tominaga, M Sato, T Mikami
IGC Proceedings (1997-2023)
The restriction fragment length polymorphisms (RFLPs) of mitochondrial DNA (mtDNA) of perennial ryegrass (Lolium perenne L.) were investigated to elucidate the genetic relatedness among the 128 cultivars including diploid and tetraploid. Many patterns of RFLPs were observed and allowed assigning of the cultivars into the main eight haplotypes of mitochondrial genome relatedness. The American cultivars were classified into haplotype I and VIII which were remote at the mitochondrial genome from each other, the European ones were distributed to all haplotypes and the tetraploid ones were mostly assigned into the haplotype V. The assessment of mtDNA RFLPs may be a …
Compared Productivity Of Local Ecotypes And Selected Cultivars Of Perennial Ryegrass (Lolium Perenne) In High Belgium, P Limbourg, Ph Lecomte
Compared Productivity Of Local Ecotypes And Selected Cultivars Of Perennial Ryegrass (Lolium Perenne) In High Belgium, P Limbourg, Ph Lecomte
IGC Proceedings (1997-2023)
The objective of the trials was to compare the productivity of local ecotypes of perennial ryegrass (Lolium perenne) issued from old permanent pastures of High Belgium to that of adapted cultivars. During 3 consecutive years 2 local ecotypes were compared, in pure seedling at 2 different levels of nitrogenous manure, to 2 cultivars frequently used in seed mixtures for pastures. Results obtained using a cutting cycle wich simulated grazing did not reveal significant differences in terms of forage production or feeding value. These results explain the weak increase in forage production recorded in pastures renovated by reseeding as …
Agricultural Performance Of Diverse Pastures Of Complementary Species And Monoculture Pastures Defoliated According To The Leaf Regrowth Stage Window Of Opportunity Criterion, B. A. Oliviera, I. F. López, L. M. Cranston, D. J. Donaghy, P. D. Kemp, J. Dörner
Agricultural Performance Of Diverse Pastures Of Complementary Species And Monoculture Pastures Defoliated According To The Leaf Regrowth Stage Window Of Opportunity Criterion, B. A. Oliviera, I. F. López, L. M. Cranston, D. J. Donaghy, P. D. Kemp, J. Dörner
IGC Proceedings (1997-2023)
In a diverse pasture of complementary species (DPCS), individual species fulfil agro-ecological functions that confer growth asynchrony and complementarity of ecosystem functions. These attributes provide yield consistency with a more even forage supply pattern across the year compared to monocultures. A common leaf regrowth stage window opportunity (LSWO) for the diverse species enables pasture defoliation that stimulates growth and persistence. The study assessed seasonal and annual growth traits of Lolium perenne (Lp), Bromus valdivianus (Bv) and Dactylis glomerata (Dg) as single grass species (Mono) sown with Trifolium repens (Tr) and as DPCS with the four species (Lp+Bv+Dg+Tr=Mix). The defoliation criteria …
Phyllochron And Growth Dynamic Of Lolium Perenne L. And Bromus Valdivianus Phil. As Affected By Soil Ph, Phosphorus And Nitrogen Restriction, Oscar A. Balocchi, M. F. Alonso, I. Calvache
Phyllochron And Growth Dynamic Of Lolium Perenne L. And Bromus Valdivianus Phil. As Affected By Soil Ph, Phosphorus And Nitrogen Restriction, Oscar A. Balocchi, M. F. Alonso, I. Calvache
IGC Proceedings (1997-2023)
Permanent grasslands are the main food for livestock production systems in Southern Chile. Therefore, it is essential to develop management tools that optimize the use of pastures. Among these tools, the phyllochron could be a better method to control grazing frequency. The aim of this study was to determine the effect of three levels of soil pH, phosphorus (P) and nitrogen (N) on the phyllochron and growth dynamic of Lolium perenne and Bromus valdivianus. Nine monophytic mini-swards of each species were established in 125 L containers for three different pH, P and N levels. For one year we measured: …
Perennial Ryegrass ‘Virazón’, A New Cultivar For Warm Temperate Areas In Uruguay And South America., Felix Gutiérrez, Javier Do Canto, R. Reyno, C. Rossi, A. Stewart, M. Carrere, F. Nolla
Perennial Ryegrass ‘Virazón’, A New Cultivar For Warm Temperate Areas In Uruguay And South America., Felix Gutiérrez, Javier Do Canto, R. Reyno, C. Rossi, A. Stewart, M. Carrere, F. Nolla
IGC Proceedings (1997-2023)
‘Virazón’ perennial ryegrass (Lolium perenne L.), a grazing-type tetraploid cultivar, was developed by the National Institute of Agricultural Research (INIA) in Uruguay as a part of the Joint Venture with PGG Wrightson Seeds and Grasslands Innovation Limited and commercially available since 2021. ‘Virazón’ was developed after 6 cycles of selection from crosses with cultivar Horizon from New Zealand based on climate adaptation, dry matter production, vigor, rust resistance, seed yield, and persistence under Uruguayan conditions. The aim was to obtain a perennial ryegrass with 3 years of consistent production. ‘Virazón’ was evaluated in forage yield trials in comparison with …