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Articles 1021 - 1050 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Evaluating Germplasm Collections Of Subterranean Clover For Plant Characteristics Influencing Seed Yield, E Piano, L Pecetti, M Romani, F Spanu Aug 2024

Evaluating Germplasm Collections Of Subterranean Clover For Plant Characteristics Influencing Seed Yield, E Piano, L Pecetti, M Romani, F Spanu

IGC Proceedings (1993-2023)

Strains of Trifalium brachycalycinumm (B) and Trifolium subterraneum • (S) were evaluated for burr burial ability and capacity to set seed when ' burial was artificially prevented. In one experiment S buried a higher • number of burrs and more deeply in the soil relative to B. There was evidel)ce that unburied burrs were undeveloped in S while a higl\ proportion of them developed in. B. In a second experiment prevention of burial drastically reduced seed yield in both species but the reduction was higher in S. Effects on yield components were. also differen.1 in the 2 species, Seeds/burr declined …

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Characterization Of Genetic Resistance To Diclofop In Italian Ryegrass, R E. Barker, G W. Mueller-Warrant, S M. Griffith, G M. Banowetz Aug 2024

Characterization Of Genetic Resistance To Diclofop In Italian Ryegrass, R E. Barker, G W. Mueller-Warrant, S M. Griffith, G M. Banowetz

IGC Proceedings (1993-2023)

Diclofop ( (:t)-2-[4-(2,4 • dichlorophenoxy) phenoxy] propanoic acid} has been used to control annual grasses in cereals since 1980 in the Willamette Valley of Oregon, USA. Populations of Italian ryegms (Lolillm multiflorum Lam.) resistant to diclofop were recently discovered. Progenies from resistant plants crossed with plants from the susceptible cvs. Marshall and Gulf were sib-mated and backcrossed to Marshall or Gulf. Resultant F2 and backcross families were screened for survival when sprayed with 1.4 kg/ha diclofop-methyl. Segregation ratios of live to dead plants showed that resistance is determined by 2 genes when a dominant allele is present at each …

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Breeding Grasses For Adaptation To Environmental Problems, M O. Humphreys, M W. Humphreys, H Thomas Aug 2024

Breeding Grasses For Adaptation To Environmental Problems, M O. Humphreys, M W. Humphreys, H Thomas

IGC Proceedings (1993-2023)

Hybrids between perennial ryegrass (Lolium perenne L.) accessions from Romania and Hungary were produced in an auempt to improve cold lolerance. Winter survival of hybrids was poorer than expected on the basis of parent performance. In a second breeding programme, introgression of genes from toll fescue (Festuca arundinacea Schreb.) into Italian ryegrass (Lolium multiflorum Lam,) was achieved using pentaploid hybrids between letraploid Italian ryegrass and hexaploid all fcscue and backcrossing twice to diploid Italian ryegrass, Good response to selection for improved drought tolerance was obtained in backcrossed progeny. It appears that in breeding for improved tolerance to …

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Is There Variability For Quality In Red Clover, C Moussett-Declas, F Faurie, J L. Tisserand Aug 2024

Is There Variability For Quality In Red Clover, C Moussett-Declas, F Faurie, J L. Tisserand

IGC Proceedings (1993-2023)

At Dijon (Prance), 36 varieties of red clover (Trifolium pratense L.) (24 diploids and 12 tetraplolds) were analysed for dry matter (DM), crude protein (CP), water-soluble carbohydrates (WSC), dry matter digestibility (DMD) and silage parameters in the primary growth. All the forage compounds analysed were significantly different, WSC mean was 5.6291,, much lower than previously reported. The tetraploid varieties appeared better than diploids for CP, WSC and DMD but poorer for DM, All the silages (except two) had excellent quality with pH under 4,0 and volatile fatty acids (VFA) content under 400 mM/kg DM, Selection for quality of forage …

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Problems, Potentialities And Progress In White Clover Breeding, I Rhodes, K J. Webb, D R. Evans, R P. Collins Aug 2024

Problems, Potentialities And Progress In White Clover Breeding, I Rhodes, K J. Webb, D R. Evans, R P. Collins

IGC Proceedings (1993-2023)

The paper outlines the problems associated with the use of white clover (Trifolium repens L.) in northern Europe and describes the potential for, and progress in, overcoming these problems through genecic improvement. Special emphasis is placed on progress in breeding for tolerance to climatic stresses, particularly high and low temperacure and water stress which also provides options for coping with future climate change. Breeding for response to environmental and biotic factors has improved general compatibility and produced varieties with increased flexibility in grazing tolerance. Such tolerance has been achieved by changing plant morphology and also by utilising greater …

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Rooting Ability In Red Clover Cuttings, H Mirzaie-Nodoushan, I L. Gordon Aug 2024

Rooting Ability In Red Clover Cuttings, H Mirzaie-Nodoushan, I L. Gordon

IGC Proceedings (1993-2023)

Because of genetic variability within cultivars, studies of cross pollinated plants often require either pure-lines or clones in order to provide fixed parents, However, in red clover (Trifolium pratense L.) because of self-incompatibility, pure lines are hard to produce, Therefore, cloning is one approach for the production of replicated plants with fixed genotypes. This experiment was conducted to assess the amount of rooting potential and its variability between several genotypes. Four prostrate accessions of red clover were used as the whole-plot treatments in a split-plot experiment with 4 replications. The subplots were different portions of the plant. Percentage of …

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Improving The Digestibility Of Warm-Season Perennial Grasses, K J. Moore, K P. Vogel, A A. Hopkins, J F. Pedersen, L E. Moser Aug 2024

Improving The Digestibility Of Warm-Season Perennial Grasses, K J. Moore, K P. Vogel, A A. Hopkins, J F. Pedersen, L E. Moser

IGC Proceedings (1993-2023)

The nutritional value of perennial warm-season grasses is limited primarily by digestible energy concentration. The relatively low digestibility of these grasses is due to their high concentration of fibre and its resistance to degradation in the rumen. The objective of this study was to evaluate quantitatively improvements in the digestibility of 5 experimental switchgrass (Panicum virgatum L.) populations in terms of a first-order digestion model in order to develop selection strategies for further improvement. The populations were developed by recurrent restricted phenotypic selection from a base population by l cycle of selection for low and 3 cycles for high …

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Breeding Improved Perennial Ryegrass In Australia, P J. Cunningham, C K. Lee, M W. Anderson, J R. Rowe, R G. Clarke, D R. Eagling, O Villalta, H S. Easton Aug 2024

Breeding Improved Perennial Ryegrass In Australia, P J. Cunningham, C K. Lee, M W. Anderson, J R. Rowe, R G. Clarke, D R. Eagling, O Villalta, H S. Easton

IGC Proceedings (1993-2023)

A phenotypic selection programme followed by half-sib family evaluation is being used for the improvement of perennial ryegrass (Lolium perenne L.). Plants have been identified with resistance to bncley yellow dwncf luteovirus, ryegrass mosaic potyvirus and crown rust. Seedling vigour and seasonal growth have been improved relative to standard cultivars. Further evaluation of progeny performance will lead to the development of improved cultivars for Australia.

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Possible Use Of Detached-Leaf Method To Evaluate Berseem Clover Germplasm For Resistance To Stemphylium Leaf Spot, F Montorsi, G Di Giambattista, P Martinello Aug 2024

Possible Use Of Detached-Leaf Method To Evaluate Berseem Clover Germplasm For Resistance To Stemphylium Leaf Spot, F Montorsi, G Di Giambattista, P Martinello

IGC Proceedings (1993-2023)

Five cultivars and S ecotypes ofberseem clover (Trifolium alexandrinum L.) were tested in the laboratory with the detached-leaf method for resistance to Stemphylium botryosun. Detached leaves were inoculated in the middle with a 1.5 µI drop of a conidial suspension. Cluster analysis was used to group cultivars and ecotypes on the basis of disease severity. II categorised the tested germplasm as resistant, moderately resistant and susceptible. However, the detached-leaf method used in this research needs validation with field and greenhouse experiments.

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Amphitetraploid Festulolium: Chromosome Stability And Female Fertility Over Intercrossing Generations, M Ghesquiere, Z Zwierzykowski, C Poisson, J Jadas-Hecart Aug 2024

Amphitetraploid Festulolium: Chromosome Stability And Female Fertility Over Intercrossing Generations, M Ghesquiere, Z Zwierzykowski, C Poisson, J Jadas-Hecart

IGC Proceedings (1993-2023)

A survey of chromosome stability and female fertility was carried out from 37 Lolium multiflorium x Festuca arundinacea var. glaucescens amphitetraploidhybrids and 86 half-sib progenies derived from 2 subsequent intercrossing generations. The chromosome associations were mostly bivalents and the frequency of aneuploid plants was low, both remaining stable over generations. Fl hybrid selection was not active in improving female fertility of progenies but the mean number of seeds per spikelet was significantly increased by 53% within the first generation and remained significan!ly unchanged in the second generation, not very far from the level of the parental species. Therefore, these amphitetraploids …

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An Agro-Ecological Approach To Breeding Subterranean Clover (Trifolium Subterraneaum L.), P.G H. Nichols Aug 2024

An Agro-Ecological Approach To Breeding Subterranean Clover (Trifolium Subterraneaum L.), P.G H. Nichols

IGC Proceedings (1993-2023)

An ecologically based breeding method has recently been adopted by the National Subterranean Clover Improvement Programme in Australia. It differs from the traditional pedigree method by allowing F2-derived lines lo continue segregating in the F4 to F6 generations in target environments under regenerating, grazed sward conditions. Advantages of the new method include: (i) assessment of field performance in the early generations; (ii) Inclusion of regeneration processes in selection procedures; (iii) allowing effects of natural selection to act on segregating lines; and (iv) allowing regional testing centres lo become involved in early generation selection. Disadvantages include possible distortion in the direction …

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White Clover To Improve Natural Grasslands In Southern Brazil, N R. Paim Aug 2024

White Clover To Improve Natural Grasslands In Southern Brazil, N R. Paim

IGC Proceedings (1993-2023)

Nine white clover (Trifolium repens L.) cultivars, among them 2 bred in Rio Grande do Sul, were evaluated in association with annuai ryegrass and pensacola bahiagrass. In a plot experiment, during 4 years, 17 harvests were cut to determine lhe dry matter (DM) yield of the mixture components. The annual ryegrass produced in· the first year 1634 kg/ha OM and in the second year, by natural reseeding, only 120 kg/ha. The pensacola bahiagrass increased DM yield from 954 kg/ha in the second year to 4588 kg/ha in the fourth year without any nitrogen (N) fertilisation. The while clover …

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Relative Performance Of Three Cultivars Of Late-Heading Perennial Ryegrass Continuously Stocks By Ewes And Lambs, H Clark Aug 2024

Relative Performance Of Three Cultivars Of Late-Heading Perennial Ryegrass Continuously Stocks By Ewes And Lambs, H Clark

IGC Proceedings (1993-2023)

Three cultivars of late-heading perennial ryegrass (Lolium perenne L.) were continuously but variably stocked with ewes and lambs so as to maintain steady state sward conditions. Net herbage production (NHP) was estimated by following the turnover of tissue on individually marked tillers and monitoring tiller numbers. Animal productivity was measured as lamb live-weight gain and ewe live­weight change and utilised metabolisable energy (UMB) estimated. The cultivars were S23, Melle and Mascot which were categorised outclassed, recommended and rejected, respectively, by the UK's National Institute of Agricultural Botany, NHP rankings for the cultivars (S23==100) were Melle 104 and Mascot 95 …

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Grasslands Prestige (G39), A White Clover Cultivar Originating From Northern New Zealand, B M. Cooper, D F. Chapman Aug 2024

Grasslands Prestige (G39), A White Clover Cultivar Originating From Northern New Zealand, B M. Cooper, D F. Chapman

IGC Proceedings (1993-2023)

G39 white clover (Trifolium repens L.) is a cultivar of similar leaf size to Grasslands Huia, but with characteristically greater stolon numbers per unit area of pasture, It was bred for sheep-grazing systems from clover ecolypes collected and evaluated in northern New Zealand. Twelve parent plants tolerant of stem nematode (Ditylenchus dipsaci) and leaf diseases, with better productivity than Huia, were selected. G39 was evaluated in Northland and at sites elsewhere in New Zealand, G39 produced more clover dry matter (DM) than Huia under rotational sheep grazing in Northland. At a hill country site in the southern North· …

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Herbage Intake, Digestibility Characteristics And Milk Production Of A Diploid And Two Tetraploid Cultivars Of Perennial Ryegrass, I W. Hageman, E A. Lantinga, H Schlepers, J H. Neuteboom Aug 2024

Herbage Intake, Digestibility Characteristics And Milk Production Of A Diploid And Two Tetraploid Cultivars Of Perennial Ryegrass, I W. Hageman, E A. Lantinga, H Schlepers, J H. Neuteboom

IGC Proceedings (1993-2023)

In a rotational grazing experiment with dairy cows on monocullures of a diploid and 2 tetraploid cultivars of perennial ryegrass (Lolium perenne L.), at a high herbage allowance the average daily production of fat and protein together was significantly higher on the tetraploids. This was associated with a difference in herbage intake of on average 0.6 kg/cow/day of organic matter and a higher concentration of volatile fatty acids and a lower pH in the rumen.

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Development And Evaluation Of Lolium Multiflorum Cultivars To Maximize Winter Production And Extend The Growing Season, D.C W. Goodenough, J.D H. Reusch Aug 2024

Development And Evaluation Of Lolium Multiflorum Cultivars To Maximize Winter Production And Extend The Growing Season, D.C W. Goodenough, J.D H. Reusch

IGC Proceedings (1993-2023)

In autumn-sown, irrigated Lolium multiflorum cultivar evaluation trials conducted at various centres covering most of the Republic of South Africa, Westerwolds-type cultivars consistently outyielded Italian-type cultivars during the critical winter months, In contrast, during spring and, in a few .cultivars, during early summer, Italian­ type cultivars were superior to Westerwolds types, Results are also given for a breeding programme aimed at improving winter, spring and summer production, increasing dry matter (DM) content and enhancing resistance to rust (Pucclnta coronata Corda),

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Persistence And Production Of Perennial Grasses In Southern Western Australia, C M. Saunders Aug 2024

Persistence And Production Of Perennial Grasses In Southern Western Australia, C M. Saunders

IGC Proceedings (1993-2023)

Persistence of 12 genera of perennial grasses was examined on 2 soil types at Green Range (annual rainfall 600 mm), in southern Western Australia, Tall wheat grass was found to be a good all round performer iit terms of persistence and production with 78-79% survival and an average dry matter (DM) production of 61 kg/ha/day. Four cultivars of Festuca ar11ndinacea were in the top 6 performers at the wetter site, producing .58-66 kg/ha/day during the sampling period even though their plant survival was less than 62%. VSPG006 (now released as Roper) and Kangaroo Valley perennial ryegrasses had significantly • better …

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Using Cytoplasmic Male Sterility In Improving Forage Productivity Of Sorghum, A A. Young, M A. Nasr, M E. Mousa, M A. Harfoush Aug 2024

Using Cytoplasmic Male Sterility In Improving Forage Productivity Of Sorghum, A A. Young, M A. Nasr, M E. Mousa, M A. Harfoush

IGC Proceedings (1993-2023)

Bighteen sorghum-sudan grass hybrids were produced by crossing 3 male fertile lines of sudan grass to different cytoplasmic male sterile lines of grain sorghum. Hybrids were evaluated with their male parents and 7 check varieties including. 6 commercial hybrids, at 4 experimental stations: Sakha, Gemmeiza, Sids and Ciba Geigy, in summer 1989. The objectives of the study were: I) to assess hybrid vigour, and 2) select the superior hybrids to be used in commercial production in Egypt. From the data obtained in this investigation, the best productivity of green and dry yield were from the F1 hybrids of ms line …

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Preliminary Isozyme Studies On Chloris Gayana (Rhodes Grass), P A. York Aug 2024

Preliminary Isozyme Studies On Chloris Gayana (Rhodes Grass), P A. York

IGC Proceedings (1993-2023)

Horizontal starch gel electrophoresis of Chloris gayana (Rhodes grass) identified enzyme systems for use as selectable genetic markers and/or polymorphic loci for cultivllf differentiation, Most enzymes from crushed leaves of Rhodes grass showed anodal migration; but peroxidases exhibited Vllfiation in a multitude of anodal and cathodal bands. Glucose- 6-phosphate dehydrogenase and malate dehydrogenase had a single; locus-zone. Malic enzyme had one clear zone, but possibly another and a trace of cathodal activity, while phosphoglucose isomerase comprised two, designated PGl-1 and PGI-2, as did superoxide dismut115e (SOD-1 and SOD-2). Phosphoglucomutase had a clear fast and a fainter, slower zone-locus. 6-phosphogluconate dehydrogenase …

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Grassland Investigation And Mapping Using Remote Sensing In Northern China, Liu Fuyuan, Li Znegyuan, Han Jinaguoguez, Xia Jingxin Aug 2024

Grassland Investigation And Mapping Using Remote Sensing In Northern China, Liu Fuyuan, Li Znegyuan, Han Jinaguoguez, Xia Jingxin

IGC Proceedings (1993-2023)

A large area of grassland in north China is an important resource for animal production, The grassland vegetations of north China were investigated and mapped by means of remote sensing from 1986 to 1990, We adopted various multiple information and multitime phase satellite images which were taken to allow optical and computer processing for complicated cases and difficult areas of grassland classification, The grasslands were divided into 8 different types and 50 groups according to surface features of Landsat images, ecological environment and vegetation analysis, The warm shrub and herbosa grassland, which ls distributed mainly in the rocky mountainous regions, …

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Grazing Management For The Control Of Vulpia Spp. In Pastures, C E. Jones, R.D B. Whalley Aug 2024

Grazing Management For The Control Of Vulpia Spp. In Pastures, C E. Jones, R.D B. Whalley

IGC Proceedings (1993-2023)

The effect of strategic grating in spring and autumn on seed production, recruitment and seedling survival of Vulp/11 spp. was assessed in experiments at 2 sites near Armidale on the northern Tablelands of New South Wales. V11lpia spp. field populations in 1992 in autumn-grazed plots which had been heavily grazed in the previous spring were reduced 97.391, at Site 1 and 91,291, at Site 2 in comparison with similar plots which had not been grazed in the previous spring. These reductions were greater than could have been obtained by either winter cleaning or spraytopping with herbicide, the currently recommended management …

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Sustainability Of A Rocky Grassland Association Over Four Decades, K Torok, G Kosa Aug 2024

Sustainability Of A Rocky Grassland Association Over Four Decades, K Torok, G Kosa

IGC Proceedings (1993-2023)

The monitoring of vegetation changes Is essential for predicting the direction of future changes. Historic Braun-Blanquet type relev6s of a grassland association were resampled after 4 decades. Ordination techniques were applied to the joint data set. Important displacement of the relev6s was observed in the ordination space, though there is no complete separation of the historic and recent relev6s. No consistent change in species number, no decrease in diversity was experienced, The displacement of relev6s was the consequence of shif'l in the spectrum of life strategies of species: invasion of annuals, The cause of this shif'l may be the increased …

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Effect Of Excreta On Stolon Development Of White Clover Under Continuous Cattle Grazing, M I. Rebuffo, R Snaydon, J Morrison Aug 2024

Effect Of Excreta On Stolon Development Of White Clover Under Continuous Cattle Grazing, M I. Rebuffo, R Snaydon, J Morrison

IGC Proceedings (1993-2023)

The effects of cattle excreta on white clover growth in perennial ryegrass-white clover pastures were studied under continuous grazing. During 2 6-week periods in June-July and September-October. Caltle selectively grazed the sward where urine had been recently voided and subsequently grazed these areas more fequently than other areas, while grazing the sward adjacent to the dung pats less intensively than other areas. Despite differences in of herbage mass and light interception resulting from altered grazing patterns, dung did not affect the density of white clover (Trifolium repens L,) growing points or the number of branches per stolo1i in the …

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Allelopathic Effects Of Endophyte In Perennial Ryegrass Residues On Young Subterranean Clover Plants, F J. Snell, P E. Quigley Aug 2024

Allelopathic Effects Of Endophyte In Perennial Ryegrass Residues On Young Subterranean Clover Plants, F J. Snell, P E. Quigley

IGC Proceedings (1993-2023)

Earlier research in Australia and New Zealand has shown that legume growth and persistence may be reduced in the presence of perennial ryegrass (Lolium perenne L.) which frequently contains the endophyte Acreonium lolli Mechanisms to explain these effects need further elucidation. A pot experiment, conducted in a glasshouse, showed that a mulch of senescent perennial ryegrass, which frequently contained A. lolli, reduced the standard of nodulation, root length and shoot and root dry weight of 32-day-old subterranean clover (Trifolium subterranean L.) plants, compared with those grown with mulches which contained less endophyte. The growth of clover plants grown …

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Agronomic Behavior Of Binary Mixtures In Basque Country Pastures, M Oyanarte, C Bastida, M Rodriguez Aug 2024

Agronomic Behavior Of Binary Mixtures In Basque Country Pastures, M Oyanarte, C Bastida, M Rodriguez

IGC Proceedings (1993-2023)

The present work deals with the total yield and botanical composition of binary mixed pastures resulting from paired combinations of 8 grasses (Italian, perennial and hybrid ryegrass, cocksfoot, tall fescue, timothy, meadow softgrass and prairie grass) and 3 legumes (red clover, white clover and birdsfoot trefoil) with two levels of N, 160 and 320 kg/ha, during a 2-year field trial. In both years prairie grass was the most productive grass in the different combinations and its yield increased considerably with the high rate of N. Cocksfoot and timothy were slow to establish but in the second year they yielded well, …

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Establishing Alfalfa Without Tillage, D W. Koch Aug 2024

Establishing Alfalfa Without Tillage, D W. Koch

IGC Proceedings (1993-2023)

Establishing alfalfa (Medicago saliva L.) without prior tillage offers advantages over traditional methods in terms of reducing energy and labour requirements, erosion hazard and improving timeliness of operation. An economic advantage to the no-till method has been apparent in recent years. Alfalfa was seeded without prior tillage.after annual crops and into perennial sods. Alfalfa was no-till seeded into perennial sod with less than 10% of the energy and labour required by the conventional tillage method. Alfalfa no-till seeded less than 1 week after sod was treated with glyphosate, was less vigorous and yielded less the seeding year than alfalfa …

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Effect Of Manipulative Management Options On A Degraded Pasture Within The Astrebla Spp. Grazing Lands Of Western Queensland, J J. Bushell, J A. Reynolds, D C. Cowan, D G. Phelps, J A. Milson Aug 2024

Effect Of Manipulative Management Options On A Degraded Pasture Within The Astrebla Spp. Grazing Lands Of Western Queensland, J J. Bushell, J A. Reynolds, D C. Cowan, D G. Phelps, J A. Milson

IGC Proceedings (1993-2023)

A reduction in Aslrebla spp., and an increase in less palatable and less desirable forbs (Malvastmm americanum Psoralea cinerea), was identified as a problem in some paddocks of the Astrebla grazing lands of central western Queensland's clay soils. To determine possible rehabilitation for these pastures and assist the recovery of Astrebla spp,, a 2-year experiment was conducted near Muttaburra, Queensland (460 mm average annual rainfall), Six main treatments (nil, tine ripping, herbicide, slashing, fire, and a pioneering grass) were combined in a 6x2x2 split piot structure with grazed/not grazed and with additional Astrebla lappacea seed sown/not sown. Interim …

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Autumn Management Of Grass-Legume Pasture, D P. Belesky, J M. Fedders, A S. Laidlaw Aug 2024

Autumn Management Of Grass-Legume Pasture, D P. Belesky, J M. Fedders, A S. Laidlaw

IGC Proceedings (1993-2023)

Duration of autumn grazing may affect the long-term balance of grass and legume in a sward. Effects of early and late autumn closing dates were studied on productivity and morphology of orchardgrass (Dactylis glomerata) and white clover (Trifolium repens) in replicated grazed swards. Early-closed paddocks continued to accumulate herbage during autumn, resulting in greater winter senescence than late-closed paddocks. Spring-cut herbage mass was not affected by autumn management; however, late closing had significantly more clover than early closing. Early-closed paddocks were grass domlnanl, with few relatively large tillers and few clover growing points compared with late-closed …

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Changes In Productivity Associated With Replacement Of Heteropogon Cotortus By Aristida Species And Chrysopogon Fallax In The Savannas Of South East Queensland, F P. Wandera, P C. Kerridge, J A. Taylor, H M. Shelton Aug 2024

Changes In Productivity Associated With Replacement Of Heteropogon Cotortus By Aristida Species And Chrysopogon Fallax In The Savannas Of South East Queensland, F P. Wandera, P C. Kerridge, J A. Taylor, H M. Shelton

IGC Proceedings (1993-2023)

Heteropogon contortus-dominated rangelands, which cover 22 million ha, are the most important areas for beef production in northern Australia. Due to overgrazing, this dominant species ,is disappearing and is being replaced by unpalatable species such as Aristida and Chrysopogon in a patchy mosaic pattern. In a large graiing experiment· adjacent to the CSIRO Narayen research station: in south-east Queensland on granite country, patches dominated bf the unpalatable grasses comprised 24-32% of the area. Aristida-dominant and Chrysopogon-dominant patches had lower productivity (1000 and 650 kg/ha, respectively) than areas dominated by Heteropogon contorus (1850 kg/ha). It was estimated that a rangeland …

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Dynamics Of Stylosanthes Species In Mixed Pastures In A Marginal Environment, J G. Mcivor, C J. Gardener Aug 2024

Dynamics Of Stylosanthes Species In Mixed Pastures In A Marginal Environment, J G. Mcivor, C J. Gardener

IGC Proceedings (1993-2023)

The growth and population dynamics of Stylosanthes hamata cv. Verano and S. scabra cv. Seca were measured in mixed, oversown pastures at Hillgrove (AAR=535 mm) near Charters Towers. Over a 10-year period mean stylo yields ranged from 20 kg/ha to 1800 kg/ha. During the first 3 years Verano outyielded Seca but in the last 7 years Seca had greater yields. Plant density was greater for Verano lhan Seca during the early years but the situation was reversed in later years. The Seca plants lived longer than Verano plants and there was a greater proportion of perennial plants in the Seca …

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