ORCID Profile
0000-0002-7120-8103
Current Organisation
NSW Department of Primary Industries
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Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP09258
Abstract: Soil water content (SWC) was monitored in an intermittently dry environment in 2003–08, for the following pasture types: perennial ryegrass (Lolium perenne cv. Skippy), lucerne (Medicago sativa cv. Venus), phalaris (Phalaris aquatica cv. Atlas PG), a lucerne halaris mixture, digit grass (Digitaria eriantha ssp. eriantha cv. Premier), and old man saltbush (Atriplex nummalaria). Perennial ryegrass and phalaris pastures persisted until late winter–early spring 2005 and, after that time, were maintained as degraded annual grass pastures and bare fallows, respectively. For all pasture types, mean SWC was generally higher for the 0–0.9 m soil depth than the 0.9–2.1 m (63 v. 51 mm of water per 0.2 m soil layer). At a soil depth of 0–0.9 m, few significant differences in SWC occurred among pasture types. However, significant differences among pasture types were recorded in SWC at depths of 0.9–2.1 m for these perennial-based pastures with low herbaceous plant densities. At this depth the SWC of lucerne halaris was lower (P 0.05) than that of perennial ryegrass and phalaris pasture types in March 2005 (Day 500), and that of the degraded annual grass pasture in August 2006 (Day 1000) and December 2007 (Day 1500). Overall, maximum extractable water was highest (P 0.05) for digit grass and old man saltbush pasture types (~180 mm) and lowest for the bare fallow (99 mm). Estimates of root depth were highest (2.0 m) for the lucerne halaris pasture type.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP09036
Abstract: Forage grass cultivars must have adequate grazing tolerance for use in the grazing systems for which they are intended. Response to 2 cycles of selection for persistence under heavy grazing pressure was examined in 3 winter-active breeding populations of the productive perennial grass, phalaris (Phalaris aquatica L.), from 2000 to 2003, at Bulart in western Victoria and Rye Park on the Southern Tablelands and Tamworth on the North-West Slopes of New South Wales. There was one continuously grazed and one rotationally grazed set of plots at Bulart to examine the effect of grazing management. All sites were affected by drought in later years but drought stress was most severe at Tamworth. A strongly positive linear response to selection was observed in an analysis of persistence measured as frequency of phalaris plant base across the 3 sites (excluding the rotational treatment at Bulart), but response interacted with site. By 2003, linear response averaged 14% frequency units or 34–40% proportional response per cycle at Rye Park and the continuously grazed plots at Bulart, sites that were environmentally suited to survival of phalaris. In contrast, response to selection was absent or slightly negative at Tamworth where conditions were drier and hotter. Populations responded similarly in analyses across all 3 sites but 1 population was less responsive when analyses were restricted to Bulart and Rye Park. Herbage mass measurements in 2001 at Bulart and 2002 at Rye Park indicated positive responses to selection, which were increasingly linked to frequency over time. Rotationally grazed plots at Bulart displayed higher frequency than continuously grazed plots after 3 years of grazing. The experiment showed that grazing tolerance was a heritable trait in the populations tested when environmental constraints were not limiting and that useful improvements in persistence had been obtained compared with existing cultivars.
Publisher: Springer Science and Business Media LLC
Date: 08-02-2019
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP09037
Abstract: Phenotypic changes in populations of perennial grasses are known to occur in response to natural or deliberate selection under grazing. These changes may have agronomic significance. Associated changes in morphology and yield potential of young stands in response to 2 cycles of selection for grazing tolerance were examined in 3 winter-active breeding populations of the perennial grass, phalaris (Phalaris aquatica L.). Levels of alkaloids which potentially could affect palatability were also examined. There was a decline in seedling growth and autumn and winter yield in spaced plants of 6.3–7.5% per cycle pooled across populations. Seedling growth measured in sown swards at 2 sites was not affected by selection. Visually estimated sward yield in the second year, ignoring large gaps, agreed with the spaced plant results but the decline was not significant at P ≤ 0.05 when herbage yield was measured by mowing, probably due to effects of plant density. On balance, it was concluded that a decline in in idual plant yield of 6–7% per cycle had occurred but this could be compensated by higher density, particularly over time as differences in persistence under grazing developed. The most pronounced morphological response to selection under grazing was towards a more densely tillered growth habit, although one exception occurred. There was also a tendency towards a more prostrate growth habit and later heading, but this was significant only for the most erect and earliest maturing population. Two cycles of selection did not significantly affect summer activity or area of plant base in any population. Tryptamine alkaloids were below the level likely to affect palatability but tended to increase with selection, particularly in a very low tryptamine base population, which suggested that they may play a role in persistence. Because of potentially deleterious effects on yield, care is required in using this selection method. A balance of yield potential and grazing tolerance appropriate to the management system is needed.
Publisher: Wiley
Date: 18-02-2019
DOI: 10.1111/GFS.12409
Publisher: MDPI AG
Date: 17-08-2021
Abstract: Weeds are an increasingly significant issue inhibiting agricultural production worldwide. Forage conservation could form part of an integrated weed management program if ensiling killed weed seeds. In Experiment 1, seeds of five grass (Hordeum spp., Bromus diandrus, Bromus hordeaceum, Lolium rigidum and Vulpia spp.) and two broad-leaved temperate weed species (Echium spp. and Raphanus raphanistrum), that were either untreated, ensiled in pasture (Trifolium subterranean/Lolium rigidum mixture) forage for a minimum of three months, underwent 48 h in sacco digestion in steers or ensiled prior to digestion were tested for germinability and viability. In Experiment 2, seeds of eight tropical weed species (Cenchrus ciliaris, Rumex spp., Bidens pilosa, Sorghum halepense, Urochloa panicaoides, Paspalum dilatatum, Brachiara eruciformis and Choris truncata) were ensiled in Sorghum bicolor forage. In Experiment 3, L. rigidum and R. raphanistrum seeds were ensiled in either Medicago sativa forage wilted to 336.9, 506.5 or 610.7 g/kg dry matter or in chaff to which water or water plus acid was added at rates to achieve 350, 450 or 550 g/kg dry matter content with lactic plus acetic acid added in the ratio of 3:2 at 80, 45 or 10 g/kg DM, respectively. In Experiment 4, L. rigidum and R. raphanistrum seeds were ensiled in cotton wool to which water or water plus acid was added at the same rates as in Experiment 3. Germinability of all seeds following ensiling was substantially reduced or nil. The extent of the reduction varied with species and experiment. In sacco digestion reduced germinability in Experiment 1, but to a lesser extent than ensiling while ensiling plus digestion reduced germination rates to 0%.
Publisher: Wiley
Date: 04-07-2016
DOI: 10.1111/GFS.12239
Publisher: Wiley
Date: 19-07-2016
DOI: 10.1111/GFS.12237
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/EA05294
Abstract: Two studies to evaluate annual pasture legumes were sown in replicated plots near Tamworth, New South Wales. In the first (experiment 1), 24 entries were sown in 1995 and in a second study (experiment 2) 33 entries were sown in 1996. Green herbage mass (kg DM/ha) was assessed in the year of sowing (spring) and thereafter four times per year until spring 2000. Limited data were also collected to estimate maturity grading, seed yield and seedling regeneration. For each experiment, green herbage mass data were examined using cubic smoothing splines and at the end of each study, green herbage mass values predicted from the model were used to assess the significance (P = 0.05) of differences between cultivars or lines. In spring 2000 (experiment 1), Trifolium subterraneum var. brachycalycinum cv. Clare had the highest rank of the cultivars and lines, and T. michelianum cv. Paradana the lowest (previously cultivated site). For the native pasture site, CPI 70056B subterranean clover had the highest rank and Ornithopus compressus cv. Paros the lowest. In experiment 2, Clare had the highest rank in spring 2000 and T. resupinatum cv. Bolta had the lowest ranking. Long-term green herbage mass appeared to be strongly influenced by maturity grading, but other factors may have affected the performance of annual Medicago spp., O. compressus, T. resupinatum, and T. michelianum. Results from the current study and previous reported research indicated that T. subterraneum var. subterraneum cvv. York (evaluated as CPI 89846B) and Junee and T. subterraneum var. brachycalycinum cv. Clare performed best in northern New South Wales.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP10011
Abstract: The comparative herbage production and persistence of 7 chicory cultivars and 14 accessions collected from erse regions of the world were evaluated over 3 years in 5 agro-ecological environments across New South Wales (NSW), Victoria (Vic.) and South Australia (SA). Results showed that all cultivars had higher herbage yields than the accessions, but varied greatly among sites. Averaged across all cultivars, total herbage yields were up to 24.6 t DM/ha over 3 years at the Hamilton, Vic. site, but as low as 6.9 and 5.7 t DM/ha at the Wagga Wagga and Bookham, NSW sites, respectively, where chicory only persisted for 2 years. In contrast, the average herbage yield of all accessions was only one-half of that produced by the cultivars at the Hamilton site and about one-third of that at the other 4 sites. All cultivars and accessions persisted well under the favourable climate conditions experienced at the Hamilton site. In contrast, severe drought in 2006 resulted in the death of chicory swards at the Wagga Wagga and Bookham sites, and substantial declines in persistence at the Manilla, NSW and Willalooka, SA sites. Nevertheless, accessions collected from Australia and Asia were more persistent than some of the cultivars and may provide opportunities to select genotypes better adapted to intermittently dry mixed farming systems in south-eastern Australia. Our findings indicated that the current cultivars were best suited to sites similar to the Hamilton site in the winter-dominant, higher rainfall zone of south-eastern Australia. Under these conditions chicory was likely to be productive and persistent for 4 years or longer. In the drier mixed farming zone, chicory may be more suitable in shorter (2–3-year) pasture phases. Further research is required to identify those factors contributing to poor persistence.
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/EA07135
Abstract: To review pasture species for regions with 465–680 mm average annual rainfall, 22 perennial grasses and herbs were evaluated for pasture establishment and productivity in four states at seven locations where the arrest of groundwater recharge is considered necessary to ameliorate dryland salinity. Species represented introduced and native, temperate and subtropical grasses, chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.). This report describes establishment and yield the following paper describes persistence and root characteristics. Yields were measured over 2–3 years except at one site, which suffered severe drought. Perennial ryegrass (Lolium perenne L., cv. Avalon) and tall fescue (Festuca arundinacea Schreb. = syn. Lolium arundinaceum. (Schreb.) Darbysh., cvv. AU Triumph and Resolute MaxP), cocksfoot (Dactylis glomerata L., cv. Porto) and phalaris (Phalaris aquatica L., cv. Holdfast and Australian) were the most productive species, with dry matter (DM) yields of 13.6–15.1 t/ha. For summer growth, Porto and Rhodes grass (Chloris gayana Kunth, cv. Katambora) were the most productive species relative to Australian in summer, Porto and Katambora produced 41% and 26% more DM, respectively (95% confidence). Perennial ryegrass (cv. Avalon), tall fescue (cv. Resolute MaxP) and chicory (cv. Grouse) were particularly valuable for autumn growth Avalon was 30% more productive than Australian. Tall fescue (cv. Resolute MaxP) was 32% more productive than Australian in winter. Avalon and AU Triumph were the most productive grasses and herbs in spring. Based on natural rainfall over the 2–3 years of measurement, the mean water use productivity, ignoring any runoff, was 10.5 kg DM/ha.mm for the three most productive species. Apart from kangaroo grass (Themeda triandra Forssk), native grasses gradually established, but over a prolonged period weeping grass (Microlaena stipoides (Labill.) R.Br., cv. Wakefield) was the most rapid. Perennial ryegrass, tall fescue, cocksfoot and phalaris maintained productive yields across a erse range of soils and climates. Exploration of the ersity within these species in a nationally coordinated program of genetic improvement appears warranted for improving reliability and expanding the zone of adaptation.
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/EA07136
Abstract: Field experiments were carried out at seven sites in southern Australia from 2002 to 2006 to measure changes in plant frequency, root characteristics and summer activity for a range of grass and herb species or cultivars. Annual rainfall during the experimental period was on average 75 mm lower than the long-term average. Plant frequency differed significantly between species and between sites. Temperate grasses generally had higher frequencies than subtropical grasses, native grasses and herbs. Cocksfoot (Dactylis glomerata cvv. Currie, Porto), tall wheat grass (Thinopyrum ponticum cv. Dundas), winter-active tall fescue (Festuca arundinacea cvv. Fraydo, Resolute MaxP) and phalaris (Phalaris aquatica cvv. Atlas PG, Australian) were the most persistent of the temperate perennial species over the experimental period. The frequency of most cultivars declined from year 2 to year 4 after establishment, but the frequency of kikuyu (Pennisetum clandestinum cv.Whittet) and wallaby grass (Austrodanthonia richardsonii cv. Taranna) increased by over 5% from year 2 to year 3, and cocksfoot (cv. Currie) increased from year 3 to year 4. At two sites where measurements were made, there were significant differences in rooting depth between species. Whittet kikuyu was the deepest among all species with a rooting depth of up to 2 m, followed by phalaris, tall fescue, grazing brome (Bromus stamineus) and tall wheat grass. Root density was affected by plant genotype and soil structure. Root density of the species varied significantly in the subsoil (0.1–1.1 m) and deeper subsoil (1.1–2 m) but not in the topsoil (0–0.1 m). Green-leafiness over summer was generally higher for subtropical grasses, native grasses, herbs and some summer-active temperate grasses, than most temperate grasses with high summer dormancy.
Publisher: Wiley
Date: 19-07-2015
DOI: 10.1111/GFS.12130
Publisher: Wiley
Date: 28-10-2018
DOI: 10.1111/GFS.12392
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/AR06206
Abstract: This paper reports on several studies conducted to better understand the variability between lucerne cultivars and lines, and use this to predict persistence in dryland grazing pastures in eastern Australia. Morphological traits of 20 cultivars/lines were measured in irrigated and dryland spaced plant experiments. Studies were also conducted to describe variation among lucernes in their utilisation of starch and responses to water deficit, pests and diseases. Multiple regression analyses were used to develop simple models where the measured traits could be used to predict persistence of lucerne lines in dryland evaluation experiments. Although there was significant variation among cultivars/lines in most measured traits, no single trait reliably predicted persistence of cultivars/lines in dryland evaluation experiments. However, variation in persistence at both sites could be explained by models developed by multiple regression using differences in the mean lengths of the longest stems at 10% flower in summer and winter. Persistent lucernes were those that had relatively long stems in summer and short stems in winter. Water use efficiencies, starch utilisation patterns and resistances to pests and diseases of different lucernes provided some improvement to this simple model, but these improvements were not consistent.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/EA98014
Abstract: An experiment was conducted at Armidale, New South Wales to evaluate the persistence and productivity of 6 perennial grasses under 2 defoliation severities and a range of moisture/drought conditions created using a rain-out shelter. Defoliation was either moderate or severe whilst the moisture/drought conditions imposed included a non-stressed moisture treatment, and seasonal droughts simulated as 40-percentile (40-P) and 10-percentile rainfall (10-P). The treatments were applied over 2 experimental seasons spring–summer and summer–autumn. A range of measurements was taken including plant mortality, basal area, foliage greenness, herbage mass, growth rate and digestibility. Some of these results were then used as inputs to the GrazFeed decision support system to predict liveweight gain and wool growth rate from pastures growing under such conditions. Plant mortality of over 40% was observed in Dactylis glomerata and Lolium perenne under moderate (40-P) drought conditions during spring–summer. In contrast, under severe drought conditions (10-P), less than 20% of plants died, suggesting that, when combined with defoliation stress, a more common drought can present a greater hazard to plant persistence than a severe drought during spring–summer. Plant mortality was reduced and non-significant when subjected to the summer–autumn drought treatments. Plant growth and predictions of animal productivity varied widely among the species challenged with drought and defoliation stresses. Predicted liveweight gains of weaner sheep under severe drought conditions (10-P) varied between species ranging from 20 to 110 g/day. Under the same conditions, predicted wool growth rates varied between species from 5 to 11 g/wether. day, while pasture growth rates varied from a low of 0 to more than 120 kg DM/ha. day. The animal effects were due largely to differences in herbage mass and the degree to which the grass remained green. These results highlight the importance of maintaining the most productive species in pastures through drought.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP09349
Abstract: Two replacement series studies were conducted to quantify the competitive ability of seedlings of Medicago sativa (lucerne) sown in mixtures with temperate and tropical species. A temperate mixtures study (Expt 1) consisted of lucerne cv. Genesis sown with each of Phalaris aquatica (phalaris) cv. Atlas PG, Lolium arundinaceum (tall fescue) cv. Resolute MaxP, Cichorium intybus (chicory) cv. Puna, Trifolium subterraneum (subterranean clover) cv. Clare, Austrodanthonia richardsonii (wallaby grass) cv. Taranna and Avena sativa (forage oats) cv. Eurrabie. There was also an additional mixture of chicory and subterranean clover. A tropical grass mixtures study (Expt 2) included Genesis lucerne sown with each of Panicum coloratum var. makarikariense cv. Bambatsi, Dicanthium aristatum cv. Floren, Chloris gayana (Rhodes grass) cv. Katambora, Digitaria eriantha subsp. eriantha cv. Premier and Bothriochloa bladii subsp. glabra cv. Swann. In Expt 1, lucerne-phalaris mixtures were equally competitive, whereas lucerne-tall fescue mixtures over-yielded. Chicory was aggressive in mixtures with lucerne and subterranean clover similarly forage oats was more competitive than lucerne. Subterranean clover was competitive against lucerne at harvest 1, but by harvest 2 the low cutting height had reduced its competitiveness. Lucerne was more aggressive than wallaby grass. In Expt 2, all tropical grass-lucerne mixtures over-yielded however, lucerne was generally more competitive than the grasses, except for Rhodes grass at harvest 1. While our study indicated that mixtures of lucerne seedlings with phalaris or tall fescue may be compatible, mixtures with tropical grasses were more likely to result in lucerne seedling dominance. This competitiveness may be overcome by either spatial or temporal separation and we discuss the concept of using mixtures to exploit environmental niches.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP08357
Abstract: Two adjacent sites, one previously cropped and the other a native pasture, were sown with perennial temperate and tropical grasses and herbs (Expt 1), Phalaris aquatica (phalaris) and Festuca arundinacea (tall fescue) cultivars or lines (Expt 2), and perennial tropical grasses (Expt 3) near Manilla, NSW. Establishment, herbage mass and plant frequency were assessed in 2003–06 to (i) identify cultivars/lines with superior persistence, (ii) detect possible mechanisms required for successful production and persistence in a summer-dominant rainfall environment, and (iii) examine the comparative performance of the species groups when sown into previously cropped and native pasture areas. Plots were fertilised annually and grazed or mown at least seasonally. Most cultivars/lines persisted at the previously cropped site, while those on the native pasture site had to be resown and generally failed to persist beyond the first year. At the previously cropped site, summer-dormant tall fescue cv. Resolute MaxP® was the most persistent of the grasses evaluated in Expt 1. Grasses such as Lolium perenne cv. Avalon and Bromus stamineus cv. Gala did not perenneate, but regenerated annually from seed. Native grasses generally had poor establishment however, Austrodanthonia richardsonii and A. fulva tended to increase in plant frequency over time. Chloris gayana (Rhodes grass) cv. Katambora and Panicum maximum (panic) cv. Gatton were the only tropical grasses that established in Expt 1, and both had plant frequencies similar (P 0.05) to the temperate grasses at the final assessment. In Expt 2, Resolute MaxP again was the most persistent cultivar/line. Several experimental lines of phalaris (e.g. T39 and M225) had high herbage mass and good persistence compared with commercial cultivars. In Expt 3, Katambora Rhodes grass and Digitaria eriantha ssp. eriantha (digit grass) cv. Premier were the most persistent cultivars and had the highest herbage mass. These data highlighted summer dormancy in temperate grasses and frost tolerance in tropical grasses as two possible mechanisms important for persistence of grasses on the North-West Slopes of NSW and the risks associated with sowing perennial grasses into established native pastures.
Publisher: CSIRO Publishing
Date: 2009
DOI: 10.1071/CP08374
Abstract: Seedlings of three perennial tropical grasses, Chloris gayana cv. Katambora (Rhodes grass), Panicum coloratum var. makarikariense cv. Bambatsi (panic grass), and Digitaria eriantha ssp. eriantha cv. Premier (digit grass), were each grown in replacement series mixtures with seedlings of the annual summer-growing grass weeds Urochloa panicoides (liverseed grass) and Echinochloa colona (awnless barnyard grass). A separate experiment examined the competitiveness of seedlings of the three perennial tropical grasses when two species were sown together. Plants were sown 50 mm apart in boxes at a density of 307 plants/m2. Maximum likelihood estimates were used to derive parameters of a non-linear competition model using the dry weights of perennial and annual grasses. Seedlings of the summer-growing annual liverseed grass competed aggressively with those of the tropical perennial Katambora Rhodes grass. However, Bambatsi panic seedlings were equally competitive with those of awnless barnyard grass, while those in a Premier digit-barnyard grass mixture were inhibited by the presence of each other. In the perennial grass mixtures study, the performance of both Premier digit and Bambatsi panic was adversely affected by the presence of Katambora Rhodes grass.
Publisher: Informa UK Limited
Date: 22-08-2011
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02184
Abstract: The effects of defoliation intensity and drought severity on levels of water-soluble carbohydrate (WSC), fructan, and etiolated regrowth of 6 important perennial grasses were investigated. The experiment was conducted under a rain-out shelter at Armidale, NSW, Australia, using 6 perennial grass species (Phalaris aquatica cv. Sirosa, Festuca arundinacea cv. Demeter, Dactylis glomerata cv. Porto, Lolium perenne cv. Victorian, Microlaena stipoides cv. Shannon, and Austrodanthonia richardsonii cv. Taranna) subjected to 3 moisture regimes (non-stress moisture, and moderate and severe drought) and 2 defoliation intensities (moderate and severe) over 2 seasonal sequences (spring–summer and summer–autumn).The range in WSC, fructan, and etiolated regrowth of the species varied, with Festuca and Lolium having the highest WSC and fructan concentrations. Austrodanthonia had the lowest WSC concentration of the species. Unlike the introduced species, the natives did not store fructans. The species varied in their response to the treatments imposed. Festuca and Phalaris had the highest etiolated regrowth and showed the greatest effect of defoliation intensity. Etiolated regrowth appeared to be a sensitive measure of plant status, showing the fragile nature of some of the species.The effect of defoliation intensity and drought varied with season. Defoliation intensity had little effect on carbohydrate reserves of all species, except Festuca, during summer of the spring–summer experimental season. During the summer–autumn experimental season, severe defoliation reduced the rate of accumulation during the period December–April. Drought affected carbohydrate accumulation and utilisation. Carbohydrates that had been accumulated at the end of spring of the spring–summer experimental season in plants affected by drought were utilised during summer. However, if drought commenced in summer, carbohydrate accumulation continued for 120 days in all species studied, and 180 days in Lolium and Phalaris.Autumn appeared to be a period when plant reserves were particularly susceptible to stress. The importance of WSC, fructans, and etiolated regrowth as measures of plant reserves, and their role in persistence were discussed.
Publisher: CSIRO Publishing
Date: 2003
DOI: 10.1071/AR02185
Abstract: A field experiment was conducted to study the effects of defoliation and moisture stresses on perennial pasture grasses and to identify traits associated with their resilience. The experiment, conducted near Armidale on the Northern Tablelands of NSW, studied 4 introduced perennial grass species (Phalaris aquatica, Festuca arundinacea, Dactylis glomerata, and Lolium perenne) and 2 native grass species (Microlaena stipoides and Austrodanthonia richardsonii) subjected to 3 moisture regimes (non-stress moisture, moderate drought, and severe drought) and 2 defoliation intensities (severe and moderate). Basal area, herbage mass, phenological growth stage, nitrogen concentration, root mass, and rooting depth were compared over 2 independent 6-month periods: spring–summer (1 September 1994–28 February 1995) and summer–autumn (1 December 1994–31 May 1995). Multiple regression was used to determine which traits were important for determining plant resilience.The differences between species and their respective responses were evident in the traits measured. In general, basal area tended to increase over summer and show little change during autumn. Severe defoliation stimulated plant growth, resulting in higher harvested herbage mass than from those moderately defoliated. Reproductive development was suppressed by severe drought and reduced by moderate drought. Severe defoliation suppressed flowering of Dactylis and Lolium at both drought intensities, compared with moderate defoliation. Phalaris, Festuca, and Austrodanthonia were the deepest rooting species during spring–summer, and Dactylis the shallowest. All species had similar rooting depths during summer–autumn, with those under severe and moderate drought having the deepest and shallowest rooting, respectively.Carbohydrate reserves and basal area were important traits for determining plant resilience during spring–summer. During summer–autumn, maintaining basal area and plant biomass through moderate grazing was important for resilience.
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/AR04300
Abstract: The survival of available cultivars of introduced temperate perennial grasses has been less than adequate under grazing on the North-West Slopes of New South Wales. A wide range of germplasm of the Mediterranean perennial grass, phalaris (Phalaris aquatica L.), was assessed for persistence, seedling vigour, winter yield potential, time of reproductive development, and summer dormancy in grazed swards at 3 sites (Manilla, Tamworth, Purlewaugh) from 1998 to 2001. The aim was to understand population characteristics that influence persistence in this environment and to identify persistent populations. Good establishment was achieved after above-average winter–spring rainfall in 1998. Persistence was high during the first year of grazing (1999) but declined under lower rainfall during 2000 at the Manilla and Tamworth sites. By 2001, a wide range in persistence had developed at these 2 sites. A group of wild populations, mainly from North Africa, was identified as being more persistent at both sites than any available cultivar. Two early cultivars, Sirocco and CPI 19305, were also relatively persistent. None of the germplasm survived a subsequent severe drought in 2002 at Manilla and Tamworth. Persistence remained high despite higher grazing pressure at the Purlewaugh site until the 2002 drought year, when changes in survival correlated with those at the other sites occurred. Biplot analysis indicated that early reproductive development and high summer dormancy were associated with persistence in both wild and bred populations. High seedling and winter growth potential was less strongly associated with persistence. Wild and bred germplasm from North Africa displayed these characteristics to a marked extent, whereas germplasm from southern Europe and Sardinia did not and was less persistent. A group of wild populations mainly from Morocco was identified as the basis for cultivar development.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/CP09360
Abstract: The persistence and productivity of a erse range of Medicago sativa germplasm including representatives of subspecies sativa, caerulea, falcata and varia were examined at 3 field sites in south-eastern Australia over 4 years. Sites were located at Tamworth, Barmedman and Hamilton, forming a 1200 km north–south transect with rainfall distribution varying from predominantly summer dominant in the north to winter dominant at the most southerly site. Several entries of subspecies varia and caerulea had herbage yields and persistence equivalent to that of M. sativa subspecies sativa cultivar Sceptre, a highly winter-active type that was used as a standard. The cultivar Cancreep, a cross of M. falcata and M. sativa, had a total yield over 3 years equivalent to 84–91% of Sceptre at the 2 sites where it was sown. In idual lines of subspecies varia demonstrated good persistence under grazing and were ranked 2nd and 6th out of 35 accessions for frequency in year 4 at Barmedman, the driest site, and 5th, 7th and 9th out of 33 accessions at Tamworth, the more summer-dominant rainfall site. Entries of subspecies falcata were among the least productive and persistent. The study indicated that germplasm from subspecies caerulea and varia offered hitherto unexploited potential for selection as persistent and drought-tolerant perennial legume alternatives to M. sativa for extensive low management grazing systems of south-eastern Australia.
Publisher: Informa UK Limited
Date: 24-05-2011
Publisher: Informa UK Limited
Date: 18-07-2018
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CP17139
Abstract: A growth-cabinet study was conducted to determine the optimum temperature range for seedling emergence of seven tropical grasses commonly sown in the frost-prone, summer-dominant rainfall region of inland northern New South Wales. The grasses were Bothriochloa bladhii subsp. glabra (forest bluegrass) cv. Swann, Bothriochloa insculpta (creeping bluegrass) cv. Bisset, Chloris gayana (Rhodes grass) cv. Katambora, Digitaria eriantha (digit grass) cv. Premier, Panicum coloratum var. makarikariense (makarikari grass) cv. Bambatsi, and Megathyrsus maximus (panic) cvv. Gatton and Megamax 059. Six constant temperatures were used, ranging from 10°C to 35°C in 5°C increments. Katambora Rhodes grass was the only grass to emerge at 10°C seedlings of all grasses emerged at temperatures °C. Optimal temperature range for emergence varied between species, falling into three groups: low (Bisset creeping bluegrass 16−22°C) intermediate (Premier digit grass 21−32°C, Swann forest bluegrass 23−31°C, Megamax 059 panic 23−35°C, Gatton panic 24−32°C) and high (Bambatsi makarikari grass 24−35°C, Katambora Rhodes grass 24−35°C). The temperature range at which 50% of optimum emergence occurred was 12−14°C for Katambora Rhodes grass, Bisset creeping blue and Premier digit, and 17−18°C for the panic grasses, Swann forest bluegrass and Bambatsi makarikari grass. These temperatures provide options for sowing earlier in spring or later in summer–autumn and may assist development of sowing time options in new environments and provide insight into competition between species.
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/EA05342
Abstract: Three winter-active populations of phalaris (Phalaris aquatica L.), selected over two generations for improved persistence under grazing, were evaluated with commercial cultivars of phalaris and other temperate perennial grasses from 1999–2003 in three environments of south-eastern Australia as part of a program to develop a cultivar for more sustainable pastures and to assess genotype × environment interaction. Grazed sites were located at Bulart in western Victoria, and Rye Park on the Southern Tablelands and Tamworth on the North West Slopes of New South Wales. At the conclusion of the experiment, the frequency of live plant base was highest at Rye Park despite soil acidity and drought. Significant variance among half-sib families in each population was also observed most frequently at this site. Frequency was intermediate at Bulart but lower than expected considering high soil fertility, probably because of high grazing pressure. Frequency was lowest at Tamworth where severe drought occurred from 2001 onwards. There was significant genotype × environment interaction for frequency among half-sib families. Significant common family variance for frequency across the Bulart and Rye Park sites was demonstrated, but not between Tamworth and either of the other sites in later years. The relationship between winter herbage mass potential and persistence differed with population and site, and was negative for one population at Bulart but positive for another population at Tamworth. Mean persistence of all families was 30% higher than winter-active controls at Rye Park and at least 40% higher at Bulart. Phalaris generally persisted better than cultivars of tall fescue (Festuca arundinacea Schreb.), cocksfoot (Dactylis glomerata L.) and perennial ryegrass (Lolium perenne L.) with some exceptions, particularly at Bulart. Development of a winter-active phalaris cultivar with improved persistence under grazing was considered possible for the Southern Tablelands and western Victorian environments with these populations but a separate program using additional germplasm will be needed for the North West Slopes environment.
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/EA07108
Abstract: Ninety-one perennial legumes and herbs (entries) from 47 species in 21 genera were evaluated at sites in New South Wales, South Australia and Western Australia over 3 years from 2002 to 2005 to identify plants with superior herbage production, persistence and the potential to reduce ground water recharge. Evaluation was undertaken in three nurseries (general, waterlogged soil and acid soil). Medicago sativa L. subsp. sativa (lucerne) cv. Sceptre was the best performing species across all sites. In the general and acid soil nurseries, Cichorium intybus L. (chicory) cv. Grasslands Puna was the only species comparable with Sceptre lucerne in terms of persistence and herbage production. Trifolium fragiferum L. cv. Palestine and Lotus corniculatus L. SA833 were the best performing species on heavy clay soils prone to waterlogging. Three Dorycnium hirsutum (L.) Ser. accessions persisted well on acid soils, but were slow to establish. Short-lived perennial forage legumes, such as Onobrychis viciifolia Scop. cv. Othello, and three Hedysarum coronarium L. entries, including cv. Grasslands Aokou, had high herbage production in the first 2 years and may be suitable for short-term pastures in phased pasture-crop farming systems. T. uniflorum L. and M. sativa subsp. caerulea SA38052 were highly persistent and could play a role as companion species in mixtures or ground cover species for undulating landscapes. Cullen australasicum (Schltdl.) G.W. Grimes SA4966 and Lotononis bainesii Baker cv. Miles had poor establishment, but were persistent. Chicory, T. fragiferum and L. corniculatus were identified as species, other than lucerne, with the most immediate potential for further selection to increase the ersity of perennial legumes and herbs adapted to southern Australian environments.
No related grants have been discovered for Suzanne Boschma.